10 MW Biomass Based Power Plant ABEIL G1. INTRODUCTION Amrit Bio Energy and Industries Ltd (henceforth abbreviated as ABEIL) has been incorporated as a Public Limited Company on 29th January,2004 . This company was promoted by Shri. K.C.Dujari, Chairman & Managing Director and Smt. Sudha Dujari, Director. ABEIL is planning to set up an 11 MW independent biomass based power plant at Jagi Road in Mayong Circle of Marigaon district in Assam. This will be the first Independent Biomass Based Power Plant at Assam. 1.1 BACKGROUND AND INTRODUCTION Biomass is known to be an important energy source for developing countries like India. Its importance is now being reaffirmed even by developed countries in view of its renewable and environment friendly character. In our country also, optimum utilization of biomass resources could not only lead to savings in conventional energy but also result in many indirect benefits. In view of this, the Ministry of Non Conventional Energy Sources has been promoting electricity generation from biomass as a means of full exploitation of its inherent energy value. Among the technologies being promoted for this purpose is the megawatt scale power generation through combustion using boiler and turbine and gasification, using Gasifier and producer gas engines. Combustion route is used for independent biomass power plants and also in cogeneration mode. These projects are covered under the Biomass Power/Cogeneration Programme of Ministry of Non Conventional energy Sources, Govt. of India. The Ministry initiated the programme for promotion of these routes of biomass utilization almost a decade back and significant achievements have been made in this period towards their commercialization and establishment as a viable and environment friendly electricity generation option. 1.2 POTENTIAL The annual generation of biomass materials covering residues from agriculture, forestry, and plantation operations, is estimated at more than 550 million tons. Biomass is classified into three categories. Crop residues like Cotton stalks, mustard stalks, etc, agro industry residues like rice husk, bagasse, etc and from waste lands and forest. Biomass is also categorized into two functional categories like, suitable for fodder and suitable for power generation. Biomass suitable for fodder is not considered for power generation, eventhough the biomass is surplus. It has been estimated that about 70-80% of these wastes are used as fodder, as fuel for
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10 MW Biomass Based Power Plant ABEIL
G1. INTRODUCTION
Amrit Bio Energy and Industries Ltd (henceforth abbreviated as ABEIL) has been incorporated
as a Public Limited Company on 29th January,2004 . This company was promoted by Shri.
K.C.Dujari, Chairman & Managing Director and Smt. Sudha Dujari, Director. ABEIL is planning
to set up an 11 MW independent biomass based power plant at Jagi Road in Mayong Circle of
Marigaon district in Assam. This will be the first Independent Biomass Based Power Plant at
Assam.
1.1 BACKGROUND AND INTRODUCTION
Biomass is known to be an important energy source for developing countries like India. Its
importance is now being reaffirmed even by developed countries in view of its renewable and
environment friendly character. In our country also, optimum utilization of biomass resources
could not only lead to savings in conventional energy but also result in many indirect benefits.
In view of this, the Ministry of Non Conventional Energy Sources has been promoting
electricity generation from biomass as a means of full exploitation of its inherent energy value.
Among the technologies being promoted for this purpose is the megawatt scale power
generation through combustion using boiler and turbine and gasification, using Gasifier and
producer gas engines. Combustion route is used for independent biomass power plants and
also in cogeneration mode. These projects are covered under the Biomass
Power/Cogeneration Programme of Ministry of Non Conventional energy Sources, Govt. of
India. The Ministry initiated the programme for promotion of these routes of biomass utilization
almost a decade back and significant achievements have been made in this period towards
their commercialization and establishment as a viable and environment friendly electricity
generation option.
1.2 POTENTIAL
The annual generation of biomass materials covering residues from agriculture, forestry, and
plantation operations, is estimated at more than 550 million tons. Biomass is classified into
three categories. Crop residues like Cotton stalks, mustard stalks, etc, agro industry residues
like rice husk, bagasse, etc and from waste lands and forest. Biomass is also categorized into
two functional categories like, suitable for fodder and suitable for power generation. Biomass
suitable for fodder is not considered for power generation, eventhough the biomass is surplus.
It has been estimated that about 70-80% of these wastes are used as fodder, as fuel for
10 MW Biomass Based Power Plant ABEIL
domestic cooking and for other economic purposes leaving behind 120-150 millions tons of
usable agro residues per year which could be made available for power generation. By using
these surplus agro residues and the wastes from forestry and plantations, it has been
estimated that more than 16,000 MW of grid quality power can be generated. In addition,
around 3,500 MW of power can be produced, if the sugar mills in the country switch over to
modern techniques of optimum co-generation. The States having the maximum potential for
bagasse based cogeneration include Maharashtra, Uttar Pradesh, Tamil Nadu, Karnataka and
Andhra Pradesh, while the States having greater potential for biomass based power
generation include Andhra Pradesh. Tamil Nadu, Karnataka, Chhattisgarh, Bihar, Punjab etc.
1.3 ACHIEVEMENTS
To tap this large potential, the Ministry has been implementing biomass power & bagasse co-
generation programme for the last 10 years. Over these years, 120 projects aggregating to
805 MW have been installed in the country for feeding power to the grid. In addition, it is
estimated that another 91 projects aggregating to 822.43 MW of electricity are under various
stages of implementation. The installed capacity includes 60 projects of bagasse based
cogeneration aggregating to 437 MW and the capacity under implementation includes 42
projects aggregating to 435.43 MW of bagasse cogenerated electricity. 60 Biomass based
power plants are already in operation with installed capacity of 342.5 MW and 49 projects are
under various stages of completion. With the commissioning of pipeline projects, Biomass
Based Power plants will contribute 730 MW, and bagasse based cogeneration projects – 898
MW. This capacity is in addition to the Biomass Gasifier systems, aggregating more than 62
MW. The States which have taken a leadership position in implementation of cogeneration
projects include Andhra Pradesh, Tamil Nadu, Karnataka and Uttar Pradesh, while for
biomass power projects, the leading States are Andhra Pradesh, Karnataka and Tamil Nadu.
Government of India, had announced the power policy, where captive power plants are not
needing any approval. With this policy, number of industries are opting for captive biomass
based power plants.
1.4 MNES POLICY
Ministry of Non Conventional Energy Sources (MNES) Govt. of India is promoting the power
generation from renewable energy sources in general and the Power Group of Ministry is
10 MW Biomass Based Power Plant ABEIL
specially promoting the Biomass Based Power Plants and Cogeneration power plants. MNES
is giving fiscal and financial benefits to the project developers.
Ministry had announced the fiscal incentives common for all renewable energy projects and
announced category wise financial incentives. These financial incentives are also
modified/revised from time to time.
Fiscal Incentives are:
1. Accelerated depreciation –100% in first year of investment
2. Income tax exemption for 10 Years
3. Sales Tax exemption for plant and machinery
a. Some states had given sales tax exemption for the equipment used in the
renewable energy project. Some states had given additional price per unit is
given from the sales tax revenue to the extent of project cost. And some
states have allowed to off set the Sales tax payment with other products of
industry
4. Excise duty or custom duty exemption
a. Excise duty and custom duty is exempted on the plant and machinery of the
project.
Ministry has also extended the Capital subsidy for Biomass Based Power plants and Bagasse
based cogeneration power plants.
At present, Government of India had announced that rapid depreciation will be upto 80% of
the project cost estimates in the first year, instead of 100% as announced earlier.
Even though notification was generally exempting the excise duty for renewable energy
projects, excise department had not given this concession to biomass based power plants and
bagasse based cogeneration systems, as the boiler and turbine can be used for conventional
systems also. Ministry of Finance, Govt. of India had issued notification no: 33/2005 dated
8.9.2005, clearly indicating that, plant and machinery needed to set up the biomass based
power plants are exempted for excise and custom duty. Copy of the notification is given below:
TO BE PUBLISHED IN PART II, SECTION 3, SUB-SECTION (i) OF THE
GAZETTE OF INDIA, EXTRAORDINARY, DATED THE 8TH SEPTEMBER,
2005
17 BHADRAPADA, 1927 (SAKA)
10 MW Biomass Based Power Plant ABEIL
GOVERNMENT OF INDIA
MINISTRY OF FINANCE
(DEPARTMENT OF REVENUE)
***
New Delhi, dated the 8th September, 2005
17 Bhadrapada , 1927 (Saka)
NOTIFICATION
No. 33/ 2005-Central Excise
G.S.R. (E).- In exercise of the powers conferred by sub-section (1) of
section 5A of the Central Excise Act, 1944 (1 of 1944), the Central Government
being satisfied that it is necessary in the public interest so to do, hereby exempts all
items of machinery, including prime movers, instruments, apparatus and appliances,
control gear and transmission equipment and auxiliary equipment (including those
required for testing and quality control) and components, required for initial setting
up of a project for the generation of power using non-conventional materials,
namely, agricultural, forestry, agro-industrial, industrial, municipal and urban waste,
bio waste or poultry litter, falling under any Chapter of the First Schedule to the
Central Excise Tariff Act, 1985(5 of 1986), from the whole of the duty of excise
leviable thereon which is specified in the said First Schedule, subject to the
following conditions,-
(i) before the clearance of the goods from the factory, the manufacturer produces
to the Deputy Commissioner of Central Excise or the Assistant Commissioner
of Central Excise, as the case may be, a certificate, from an officer not below
the rank of a Deputy Secretary to the Government of India in the Ministry of
Non-Conventional Energy Sources recommending the grant of this exemption
and the said officer certifies that the goods are required for initial setting up
of a project for the generation of power using non-conventional materials,
namely, agricultural, forestry, agro-industrial, industrial, municipal and urban
waste, bio waste or poultry litter; and
(ii) the manufacturer proves to the satisfaction of the Deputy Commissioner of
Central Excise or the Assistant Commissioner of Central Excise, as the case
may be, that there is a valid power purchase agreement between the importer
and the purchaser, for the sale and purchase of electricity generated using
non-conventional materials, for a period of not less than ten years from the
date of commissioning of the project.
[F.No. 460 / 44 /2005-Cus.V]
(Ajay)
Under Secretary to the Government of India
The indications are that, MNES is planning to give capital subsidy instead of interest subsidy.
This amount is paid to the financial institution through IREDA after commissioning of the
power project.
10 MW Biomass Based Power Plant ABEIL
1.5 STATUS OF BIOMASS BASED POWER PLANTS
Biomass Based power plants are in operation since 1992 in India, whereas these plants are in
operation in the world since mid eighties. In California, biomass based power plants of 50 MW
capacity are also in operation.
Status of Projects Commissioned and under Implementation as on 30.9.2005
PROJECTS BIOMASS POWER CO-GENERATION TOTAL
MW Nos. MW Nos. MW Nos
Commissioned 342.5 60 462.53 60 805.03 120
Under Implementation 387.04 49 435.43 42 822.43 91
Total 729.54 109 897.96 102 1627.46 211
State-Wise status of Commissioned & Under Implementation Biomass Power / Co-
Generation Projects as on 28/2/2005
S.N. State Commissioned Under Implementation
No. of Projects Capacity (in MW)
No. of Projects Capacity
(in MW)
1 Andhra Pradesh 48 257.25 19 135.96
2 Chhattisgarh 2 11 5 51
3 Gujarat 1 0.50 0 0
4 Haryana 2 6 0 0
5 Karnataka 15 151.98 20 155.66
6 Madhya Pradesh 1 1.00 0 0
7 Maharashtra 9 36.00 8 75.80
8 Punjab 3 22 1 6
9 Rajasthan 1 7.8 4 29.10
10 Tamil Nadu 19 173 9 77.00
11 Uttar Pradesh 10 73.00 8 64.30
Total 111 739.53 74 594.82
1.5.1 Status of Assam
Assam Energy Development Agency is the nodal agency to give the approvals for setting up
Biomass Based Power Plants in the state of Assam. Government of Assam is not yet
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announced the policy of power purchase from Renewable Energy Projects. This project will be
the first independent biomass based power project of Assam.
Assam State Electricity Regulatory Commission while issuing the tariff order for the financial
year 2005-06, had given special emphasis to promote renewable energy projects in the state.
Relevant portion of the order is reproduced below:
11.28 Under section 86 (e) of the Act, the Commission to:
“(e) promote co-generation and generation of electricity from renewable sources of energy by
providing suitable measures for connectivity with the grid and sale of electricity to any person,
and also specify, for purchase of electricity from such sources, a percentage of the total
consumption of electricity in the area of a distribution licence;”
11.29 The Commission has considered this requirement and decided that it is too early to
prescribe any purchase requirements on the Discom who have only been established late last
year.
11.30 The Commission is interested in encouraging renewable energy for stand alone power
systems or for remote villages not connected to the grid where a renewable energy source
may be a more cost effective option to improve the reliability of supply instead augmenting the
existing network.
11.31 ASEB had prepared a policy for small hydro power development up to 25 MW in the
State of Assam and sent the draft policy to Assam Electricity Regulatory Commission for
comment. AERC suggested a number of modifications in the policy.
11.32 To encourage generation of power from renewable sources, the Commission may
consider fixing appropriate tariff for such generation if such a generation system is connected
to grid. Wheeling charges for wheeling the generated energy will also be determined by the
Commission.
11.33 The Commission is also decided in this tariff order to create an incentive for consumers
to switch to solar hot water systems. In Assam, during winter months very high consumption of
10 MW Biomass Based Power Plant ABEIL
electricity is observed during the morning hours resulting in peaking of demand in morning in
addition to normal peak hours. One of the reason for Assam Electricity Regulatory
Commission Tariff Order FY 2005-06 this peaking of demand in the morning during winter
matters is use of water heating appliances like geysers, immersion rods etc. These heating
appliances consume high amounts of electricity.
11.34 For proper grid management it is essential that consumers should be encouraged to opt
for alternative methods to meet their water heating requirements. Solar water heaters offer an
excellent alternative to electrical water heating system and can help in a big way in reducing
the demand during the morning hours. It also results in substantial reduction in the
consumers’energy bills. So use of solar heating is, thus, a win-win situation for consumers as
well as utilities.
11.35 In order to encourage consumers to switch over to solar water heating system, the
Commission proposes to introduce a monthly rebate of Rs.30 for all consumers who have
installed such solar water heating systems for meeting their hot water requirements and these
are actually used. To avail this rebate, the consumer will be required to give the licensee an
affidavit to the effect that such a system has been installed on his premises and is being used
to meet his water heating requirements. The declaration can be verified by the licensee’s
meter readers / representative, if required. In case, any such declaration is found to be false,
the licensee apart from taking appropriate legal action against such consumer would be
entitled to recover the entire rebate allowed to such consumers with 100% penalty.
As per the estimates of 2006-07 the power requirement of ASEB is more than the availability
during the months of April, June and September-February.The deficit of 221MU for the year of
2006-07(after considering an export of 140 MU during the surplus months) has to be made up
by purchasing power from traders at an estimated average cost of Rs.3.57 per unit.To this the
indirect benefits of renewable energy needs to be added before fixing the tariff for biomass
based power.
.
1.6 ROLE OF FINANCIAL INSTITUTIONS
The leading financial institution extending the financial assistance is IREDA. Indian Renewable
Energy Development Agency (IREDA) the financial arm of Ministry also extends the financial
assistance for setting up these power plants. The other financial institutions like IDFC, IDBI,
10 MW Biomass Based Power Plant ABEIL
ICICI, HUDCO and nationalized banks like State Bank of India, Andhra Bank etc are also
extending the financial assistance.
IREDA is having the fixed rate of interest, irrespective of the promoter, but it is having different
rate of interest depending upon the capacity of the power plant and the boiler pressure.
Whereas, the other financial institutions interest rate is depending upon the credit rating of
promoter, i.e. PLR rate of financial institution and some points.
As per IREDA’s guidelines, the promoter has to bring minimum of 30% of project cost as their
equity. The interest rate for the biomass power projects is 10.5%. Repayment of loan is for the
period of 10 years after commissioning. This period is inclusive 3 years of moratorium followed
by loan repayment.
Special concession is given for North Eastern states
Concessions given to North Eastern States are given below:
Grid Connected Power Projects:
1. Rebate of 1.0% pa in interest rates
2. Exemption from Payment of
a. Registration Fees
b. Inspection Charges
c. Legal Charges (other than incurred for Recovery)
d. Expenditure Incurred on Nominee Directors
e. Front End Fee
3. Concession of 5% in Promoters contribution
4. Cost of DPR preparation for Grid Connected projects by BDAS
Security norms of IREDA are given below:
1. Equitable mortgage (Mortgage by deposit of title deeds) of all immovable properties; 2. Hypothecation of movable assets, both existing and future subject to prior charge of
Banks on specified current assets 3. Guarantees by promoters/promoter Directors and promoter companies 4. Deposit of post dated cheques in accordance with repayment schedule of principal loan
amount and interest.
HUDCO:
HUDCO also gives the term loan to the extent of 70% of the project cost. Conditions of
HUDCO are given below:
10 MW Biomass Based Power Plant ABEIL
For Bagasse/Bio-Mass Based Co-generation Schemes:
♦ Availability of bagasse and other secondary fuel (minimum 125%) of requirement for the proposed capacity of co-generation scheme
♦ Scheme may have provision for use of alternate fossil fuel such as coal as per MNES norms.
♦ Design parameter should be for 65 Kg per Sq. cm. pressure / 485 degree C temperature or higher steam parameters.
♦ The minimum capacity of the sugar unit should be 2500 TCD.
♦ Minimum annual DSCR of 1.2 and Average DSCR of 1.5.
♦ The minimum IRR of the project should be at least 15% or 3% more than HUDCO’s Rate of Interest whichever is higher.
♦ Track record of two successful crushing seasons of sugarcane with no outstanding dues in cane procurement and other goods in case of bagasse based co-generation project.
♦ The agency should not have been in loss during the last three financial years.
♦ However, in case of newly formed borrowing agencies, the proposal can be considered on the financial strength of the project/parent company with additional risk mitigation measures, such as, reduced debt exposure or increased margin of security for loan. In such cases, the balance sheet of the parent company should be examined.
Mortgage/hypothecation of all project properties (land, building and plant & machinery and
equipment) for private agencies. The total security cover should be minimum 150% (likely to
be increased to 175%)of the loan amount which shall include 125% (likely to be increased to
150%)cover towards prime security and minimum 25% in the form of collateral security (for
private sector schemes only):
The 25% collateral security cover can be through any or combination of the items indicated
below:
a. Cash deposits (minimum of 15% of loan amount) b. First charge (pledge of equity shares of any other listed Company / hypothecation /
mortgage) on personal properties of promoters. c. First charge (pledge / hypothecation/ mortgage) on other unencumbered properties of
the company (other than project assets) or other un-encumbered properties of any other person / company.
d. Pari-passu charge (hypothecation of movable properties and/or mortgage of immovable properties not financed by HUDCO) with other lenders.
In addition to the above, agency shall furnish the following: -
� Personal guarantee of Promoters. � Corporate Guarantee (if promoter is a Company) � A letter of Undertaking from the Agency to credit into the TRA all the Govt. subsidies
(including MNES subsidies) This TRA account will be under the control of HUDCO. � Assignment of contractual rights, title, interest, benefit, claims under various project
documents, agreements and all licenses, permits, approvals and consents in respect of the project.
10 MW Biomass Based Power Plant ABEIL
� Power of Attorney to sell the project assets. � Assignment of all insurance policies relating to the project up to the satisfaction of
HUDCO. � Pledging of 51% of equity shares (if available) to HUDCO. � Opening of Trust and Retention Account/Escrow Account as per HUDCO norms with
first charge on all receivables in HUDCO’s favour. � Corporate guarantee acceptable to HUDCO. � The valuation of the properties should be done by a valuer recognized by the Income
Tax Department / Nationalised Banks/ Government approved valuer for the purpose of mortgage of the properties.
Post dated cheques of the closely held Companies/Firms/Association of persons.
1.7 ASSAM GOVT POLICIES
Ministry of Non Conventional Energy Sources, Govt. of India, had given the guidelines on
power purchase by state electricity boards. Assam Government is yet to announce the policy
based on the guidelines of MNES. Based on the projected deficit of 221MU for 2006-07 for
which power is being purchased at an average rate of Rs.3.57 per unit,the cap ratef for the
sale of renewable power to the grid can be fixed at Rs.3.50 per unit for a quantum of 200MU
per annum.
1.8 ADVANTAGES OF BIOMASS BASED POWER PLANTS
Biomass based project situated in rural areas will contribute the following:
* Employment Generation
* Social Consideration
* Impact on National Power
1.8.1 Employment Generation
Biomass based power plant purely depends on the biomass collection. Biomass is obtained as
crop residue and agro industrial residue. As the biomass is having low bulk density and needs
a scientific approach for collection unemployed youths can form a NGO to collect the biomass
and sell the same to project. In nutshell biomass bank will be created. Biomass preparation
system followed by transportation will help the locals to be employed. Even power plant needs
the operating persons. This plant will keep the skilled manpower hence the local youth are
exposed to the skilled jobs. There is an indirect employment generation, as more industries
will come up in the area, due to less problems of power in that location. Hence there will be
requirement of additional manpower.
10 MW Biomass Based Power Plant ABEIL
1.8.2 Social Considerations
The setting up of the proposed plant will have a very positive impact on the purchasing
capacity of individuals as they will be able to get money for the crop residue, which at present
is either, burnt or too much under utilized.
1.8.3 Impact on National Power
Today most of the states are having distribution losses of more than 20%. As the power is
available at local point, this power will be equivalent to 120% of the conventional power plant
generation. This will save the transmission losses and also assures the reliability in power
supply.
The power generation from biomass plays an important role in supplementing the power
requirement in rural areas. This power generation leads to decentralized power generation
and improves the general condition of rural masses. At present biomass is being used to
generate steam and power in agro industries like Sugar Plants and rice mills. The biomass is
also used as fodder, domestic fuel and left out is burnt in the open areas.
Biomass is produced as crop residue, agro industry residue and waste from barren and
uncultivable land and forests. Even though cattle also generate biomass as dung, the quantity
is consumed as domestic fuel in combination with wood.
Biomass consumption is taken for domestic fuel, cattle feed, manure, thatching etc. Biomass
is consumed in industry, to generate steam. Today the surplus biomass is burnt in the open
fields due to non-availability of attractive proposal.
Biomass Based Power Plants will get the benefit of CDM.
1.9 Climatic Change Problem and Response
1.9.1 The United Nations Framework Convention on Climate Change, UNFCCC
In June 1992, the “United Nations Framework Convention on Climate Change” (UNFCCC)
was signed in Rio de Janeiro by over 150 nations. The climate convention is the base or
international co-operation within the climate change area. In the convention the climate
problem’s seriousness is stressed. There is a concern that human activities are enhancing the
natural greenhouse effect, which can have serious consequences on human settlements and
ecosystems. The convention’s overall objective is the stabilization of greenhouse gas
conncentrations in the atmosphere at a level that would prevent dangerous anthropogenic
10 MW Biomass Based Power Plant ABEIL
interference with the climate system.” The principle commitment applying to parties of the
convention is the adoption of policies and measures on the mitigation of climate change, by
limiting anthropogenic emissions Global Environmental Concerns greenhouse gases and
protecting and enhancing greenhouse gas sinks and reservoirs. The commitment includes the
preparation and communication of national inventories of greenhouse gases. The Climate
convention does not have any quantitative targets or timetables for individual nations.
However, the overall objective can be interpreted as stabilization of emissions of greenhouse
gases by year 2000 at 1990 levels. The deciding body of the climate convention is the
Conference of Parties (COP). At the COP meetings, obligations made by the parties are
examined and the objectives and implementation of the climate convention are further defined
and developed. The first COP was held in Berlin, Germany in 1995 and the latest (COP 10)
was held in December 2004,Buenos Aires, Argentina.
1.9.2 The Kyoto Protocol
There is a scientific consensus that human activities are causing global warming that could
result in significant impacts such as sea level rise, changes in weather patterns and adverse
health effects. As it became apparent that major nations such as the United States and Japan
would not meet the voluntary stabilization target by 2000, Parties to the Convention decided in
1995 to enter into negotiations on a protocol to establish legally binding limitations or
reductions in greenhouse gas emissions. It was decided by the Parties that this round of
negotiations would establish limitations only for the developed countries, including the former
Communist countries (called annex A countries). Negotiations on the Kyoto Protocol to the
United Nations Framework Convention on Climate Change (UNFCCC) were completed
December 11, 1997, committing the industrialized nations to specify, legally binding reductions
in emissions of six greenhouse gases. The 6 major greenhouse gases covered by the protocol
The only biomass available in surplus from agro industries is rice husk. Other biomass
generated from agro industries is fully consumed in industrial and other sectors. The district
wise surplus biomass available is given in the table below.
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3.21 District wise Biomass Surplus from Agro-industries in Tons
District Rice Husk Total
Kamrup 30524 30524
Morigaon 14806 14806
Grand total 45330 45330
3.6.3 Biomass Surplus from Forest and other land
The following table gives the details regarding the biomass available from the forest and
other wasteland within districts is given below.
3.22 District wise Biomass Surplus from Forest and other land in Tons
District Surplus Wood Total
Kamrup 110805 110805
Morigaon 5781 5781
Grand total 116586 116586
3.6.4 Summary of Surplus Biomass Availability
The following table gives the summary of surplus biomass from different sources within the
district.
3.23 Summary of surplus biomass in Tons
Districts Crop residue Forest and other land
Agro-industry
Total
Kamrup 0.00 110805 30524 141329
Morigaon 0.00 5781 14806 20587
Grand total 0.00 116586 45330 161916
3.7 POWER GENERATION POTENTIAL
The surplus available for the power generation purpose is 161916 tons/year, which mainly
consists of the wood from the forestlands and rice husk.
10 MW Biomass Based Power Plant ABEIL
The power potential available with the surplus wood is about 11.66 MW, and with the Agro-
industries residues i.e rice husk is about 4.53 MW. The total power potential available in
Kamrup and Morigaon districts is 16.19 MW.
3.8 BIOMASS CHARACTERISTICS, AVAILABILITY AND COST
3.8.1 Biomass Characteristics
Biomass is a renewable source of energy that can be made use of effectively for thermal as
well as electrical energy generation. All the processes in which biomass is used as fuel have a
definite bearing on the properties of the biomass material. Thus the characterization of
biomass material is essential. The characterization of biomass involves the Proximate and
Ultimate Analysis.
3.8.1.1 Proximate Analysis
The proximate analysis gives the proxy information of biomass constituents such as moisture,
volatiles, fixed carbon and ash content. The carbon content determined through this method is
not actual carbon content in the biomass but only the non-volatile part of carbon content, some
of the carbon present in the biomass escapes along with volatiles. The proximate analysis of
some biomass is given in the table.
Biomass Calorific Value
(kcal/kg) Ash (%) Volatile
matter (%) Fixed
Carbon (%)
Paddy straw 3730 15.50 68.30 16.20
Wheat straw 4146 7.70 80.60 11.70
Maize Stalks 3200 to 3800 1 to 20 60 to 85 10 to 20
Mustard stalk 4178 4.90 78.00 17.10
Cane trash 4120 10.90 70.40 18.70
Wood 3700 to 4200 1 to 3 70 to 85 15 to 20
Rice husk 3200 19.20 66.20 14.60
3.8.1.2 Ultimate Analysis
The ultimate analysis involves the determination of the elemental composition of the fuel i.e.
carbon, nitrogen, oxygen, hydrogen, sulphur etc. The determination of the total carbon and
10 MW Biomass Based Power Plant ABEIL
hydrogen and their (C/H) ratio gives an indication of the type of volatiles present in the
biomass i.e. saturated or unsaturated hydrocarbons which governs the tar formation. The
ultimate analysis of some biomass is given in the table.
Biomass Carbon (%)
Hydrogen (%)
Nitrogen (%)
Oxygen (%)
Ash (%)
Paddy straw 35.97 5.28 0.17 43.08 15.50
Mustard Stalks 40.89 5.92 6.37 39.12 7.70
Maize Stalk 35 to 40 6 to 8 0.5 to 1 50 to 55 1 to 20
Cane trash 39.75 5.55 0.17 46.82 7.71
Wood 45 to 50 5 to 7 0.5 to 0.9 40 to 48 1 to 3
Rice husk 36.42 4.91 0.59 35.88 22.20
3.8.2 Biomass Collection, handling, and preparation:
As mentioned earlier, biomass is generated from crop residues, agro industry, barren and
forest lands. The biomass obtained as crop residue and agro industry residue will have low
bulk density. The type of crop residue generated depends on the crop and also harvesting
methods. For example, if combines are used for harvesting of paddy crop, almost 5% of straw
is left in the field. The harvested straw is in the form of powder with low bulk density. This
straw needs to densified using briquetting technique. The straw left in the field, needs manual
harvesting. Manual harvested straw can be densified using bailing. If the paddy crop can be
harvested manual, total straw can be collected and can be efficiently used. Wheat straw is
also being harvested similarly.
Residue from oil seeds and pulses are brittle woody type. This type of material needs
mechanism to break into pieces of 2 to 6 inches. Usually choppers are used for this purpose.
Biomass obtained from energy plantation or wood from forest and barren land needs special
attention of preparation. This material is heavy and transportation problems are less compared
with low bulk residues.
Depending on the size and quality of material, shredders, cutters, choppers and chippers can
be used.
10 MW Biomass Based Power Plant ABEIL
3.8.3 Seasonal Biomass Availability and Cost
The major crops in this area are paddy, maize wheat, sugarcane and barley. The residues
from these crops like from these crops like paddy straw, wheat straw, maize stalks are used
as fodder. Maize cobs, cane trash, Til and Mustard stalks are used as domestic fuel. Rice
husk and Wood are the major biomass available this area which is used for industrial purpose
and domestic. After the consumption of different biomasses in various sectors cane trash,
Mustard and Til stalks, Maize cobs, wood and rice husk are available in surplus quantity,
which can be used for power generation.
As the power plant start working, biomass prices may increase to tune to 5 to 10 % in the off-
season.
3.8.4 Transportation Modes
Tractor trolleys and bullock carts are the most important means of transport available with
farmers. The farmers are having adequate means for the transportation of the biomass.
Different modes of transport like head load, hand carts, bullock carts, tractors, trucks etc. are
used for the wood transportation. Wood in large quantity is transported either by means of
tractor or trucks. While for transporting small quantity handcarts or bullock carts are used.
3.8.4.1 Bullock Carts
In rural areas, bullock cart has been the most common mode of transport. Although tractor
trolleys have also been adopted but still bullock cart is quite common particularly with the
small and medium farms even now. Farmers usually do not charge for hiring of bullock carts.
3.8.4.2 Tractor Trolleys
All the tractor owners do not own a trolley. As such special four-wheel wagons can be
developed which may carry large quantity of crop residue stalks and wood. One such wagon,
having capacity of 3-5 tones of crop residue stalks and 5-7 tones of wood. This capacity is less
than that of a truck. The initial cost of a wagon and trolley is Rs. 25000 and Rs. 20000
respectively.
3.8.4.3 Trucks
10 MW Biomass Based Power Plant ABEIL
Trucks are not at all common in rural areas for transport of agricultural wastes. However, for
handling large volumes of arhar stalks, the use of trucks may become necessary because of
time factor. These are fast moving vehicles. The capacity of a truck as mentioned above is
about 5-7 tonnes for crop residue stalks and about 8-10 tonnes for Wood.
3.8.5 Storage
Approximate biomass balance for year replicates the biomass is available in surplus in large
quantity only in the month of harvesting. This large surplus biomass quantity has to be stored
and should be used for rest of the year. Hence this biomass has to be procured in these
months and stored.
The following points may be taken into account while planning storage facilities:
• A well-drained site may be chosen.
• Leave at least 40 cms. Space between each stack to ensure proper drainage and
ventilation.
• Plan different storage sites as a safety precaution against the fire. Ample fireguards and
precautions may be taken at each of the site.
• There should be adequate natural ventilation arrangements and no natural shade of any
kind should be near the stacks.
On storage, the ash content increase, volatile matter decrease, fixed carbon increases and no
appreciable change on tone of material. The loss of VM is to be corrected with loss of weight.
3.9 BIOMASS REQUIREMENT:
Biomass Power plant will be operating at a PLF of 90% anf the rice husk requirement will be
108405 MT per annum.
3.10 CATEGORY WISE BIOMASS AVAILABLE:
The category wise biomass available from different sources is shown in the table below
3.25 Category wise availability of Biomass
10 MW Biomass Based Power Plant ABEIL
Biomass Type Residue Biomass Available
Agro Residue
Rice Husk Husk 45330
Forest & other lands
Wood Wood 116586
Grand Total 161916
3.10 AVERAGE COST OF BIOMASS:
The average cost of the biomass is taken as Rs.1500 per ton,as per current rates with annual
escalation of 5%. .
10 MW Biomass Based Power Plant ABEIL
4. PLANT AND EQUIPMENT DESIGN CRITERIA
4.0 GENERAL
This power plant will be using the combustion technology. The basic steps involve, biomass
handling, boiler, turbo generator and evacuation system.
Power generation is having direct bearing on the pressure and superheated temperature of
steam. Normally 67 bar and 490 Deg C, is used for biomass based power plants. Clearly, the
technological improvements can allow us to recover and put to use the energy, which would
otherwise be wasted. In that process, the need for new energy projects can be reduced,
resources can be preserved, and energy costs and environmental damage can be minimized,
and these benefits can be the greatest when abundant renewable biomass is the power
generation fuel. High pressure and high temperature cycles are crucial for increasing the
operating efficiency and the power output from the Biomass Power Plants. The choice of the
level of the pressure and temperature for the cycle depends on the level of confidence in the
plant operators, quality of the feed water and the water treatment systems available and the
cost of the high pressure/ temperature boiler and Turbo generator systems and the financial
benefits realizable from the power plant by way of the sale of the exportable power.
Thermodynamically, energy recovery from the Rankine Cycle is more dependent on the steam
inlet temperature than the pressure and the higher the inlet steam temperature, higher the
cycle efficiency. However, the practically attainable limits of temperatures are influenced by
the metallurgy of the boiler tubing, piping and the turbine components and the complexity of
the Creep fatigue interaction for the materials at higher temperatures.
Temperatures upto 400 0C require the use of ordinary carbon steel and beyond 400 0C low
alloy steels are employed. Above 500 0C, the requirements become stringent and expensive
and above 550 0C, the requirements are very stringent and prohibitively expensive. It is
extremely important that the selection of the temperature is done keeping in mind the nature of
the industry. Considerations such as cost, maintainability, provision of adequate safety
margins, the experience of the industry so far and the level of the operating personnel
available in the industry, force us to a selection of around 485 0C as the practical limit for the
steam temperatures. It is also important to keep in mind that the superheated steam
temperature response is a little erratic, even with a good steam temperature control system,
10 MW Biomass Based Power Plant ABEIL
mainly because of the nature of the fuel and the difficulty to ensure a correctly metered
quantity of fuel flow to the boiler. From this point of view also 485 0C is a safe selection.
Looking from purely the Cycle Efficiency point of view, with the selection of 485 0C as the
steam temperature, the Thermodynamics laws, typical construction of the turbine blading and
the practical extent of steam expansion possible in the turbines, dictate the limits of cycle
pressure. Keeping the above temperature, there is a little thermodynamic efficiency advantage
to be gained by pressures exceeding 67 ata.
The cycle parameters are decided as 64 Ata and 480 0C at the turbine throttle valve inlet.
Correspondingly the boiler outlet parameters shall be 67 Ata and 485 0C, accounting for the
pressure and temperature losses in the piping.
As the proposed power plant will be operating with the boiler outlet steam parameters of 67
Ata and 485 ± 5 0C, a feed water management program will be implemented whereby the
complete feed water requirements of the boiler will be met essentially by the condensate. The
steam Condensate will be available at 450C and will be directly used in the feed water circuit,
although with certain monitoring for certain circuits. The make up for the plant operation will be
demineralized water and a Demineralized water treatment plant of adequate capacity will be
provided.
The boiler being proposed for the biomass power plant, will be with the steam parameters of
67 Ata and 485 ± 5 0C at the boiler outlet. The boiler will be designed with a travelling grate
with electric drive to burn the biomass. The steam to biomass percentage will be achieved with
a minimum efficiency of 80 % with the dried biomass.
The power generation turbine will be a condensing machine. The turbine steam inlet
parameters will be 64 ata and 480 0C. The power plant will be operating for nearly 330 days.
The boiler will be operating on 100 % of each biomass and also in combination of various
biomasses.
The power generation cycle will be provided with a deaerator serving the dual purpose of
deaerating the feed water as well as heating the feed water with the extraction steam. The
deaerator will be operating at 2.7 ata pressure, with the deaerated feed water temperature at
105 0C. The power generation in the turbo generator will be at 11 kV level. The turbo
10 MW Biomass Based Power Plant ABEIL
generator will be operating in parallel with the ASEB Grid. The entire power requirements of
the plant and the power requirements of the auxiliaries amounting to 1 MW(approx) of the
power plant will be met by the power generated in the new turbogenerator. The balance of the
power generated i.e.10 MW in the plant will be exported to the grid.
The exportable power will be stepped up to 132 kV and will be connected to Jagi Road sub-
station 132/11 kV of ASEB located at 1-2 kms distance. Adequate space and transformer
capacities are available at the sub-station, for receiving the exportable quantum of power from
the power plant.
All the plant and systems shall be designed to achieve the best possible efficiency under the
specified operating conditions. The power plant cycle shall be designed with one Deaerator for
feed water heating. The steam requirements of the deaerator shall be met with the extraction
from the turbine & low load PRDS.
The complete plant instrumentation and control system shall be based on Distributed Control
System (DCS) philosophy, covering the total functioning requirements of measuring,
monitoring, alarming and controlling, logging, sequence interlocks and equipment protection
etc.
The ash collection points are, Grate ash from the furnace bottom and fly ash from the Air
Heaters and Electro Static Precipitator hoppers. Ash handling system will have a combination
of submerged scrapper conveyor or pneumatic conveyors. All the ash shall be taken and
stored in bins and disposed off in trucks to be used as landfill or to be used as nutrients to the
fields, or to be disposed of to Brick Kiln Owners.
The optimum arrangement of the equipment shall be determined by the consideration of
functional requirements, economy of equipment supports, installation and maintenance access
requirements.
This section of the report gives the basic criteria for design of the power plant. The design
parameters like the size, layout, ratings, quantities, materials of construction, type of
equipment etc., described in this report are approximate. Necessary changes could occur as
the detailed engineering of the plant progresses, and such changes are permitted as long as
the detailed engineering of the plant achieves the intent of this scheme.
10 MW Biomass Based Power Plant ABEIL
4.1 AMBIENT CONDITIONS
Plant Elevation above Mean Sea Level (MSL) : 262 meters
4.1.1 Temperatures
Maximum day temperature : 37 °C Minimum day temperature : 7 °C Average day temperature : 30 °C Plant design temperature (dry bulb) : 35 °C Plant design wet bulb temperature : 27 °C Plant design temperature for electrical equipment : 45 °C
The design and guarantee fuel for the power plant is rice husk and wood. Detailed availability
is given in Chapter 3.
4.3 RAW WATER
The raw water supply will be from canal / bore wells. The distance of canal from power plant is
2 Kms. This raw water is used as a makeup of the losses in the boiler blow down, cooling
tower blow down, service water etc. The raw water requirement for power plant is 1980 KL per
day. Borewells are to be dug. The raw water will be analyzed.
10 MW Biomass Based Power Plant ABEIL
4.4 MAIN PLANT AND EQUIPMENT
4.4.1 Steam Generator & Auxiliaries
The steam generating system for the power plant will use biomass collected from the fields,
sugar industry, and rice mills. Boiler will be designed to fire the biomass like cotton stalks, and
mustard stalks from crops, with a Maximum Continuous Rating (MCR) of 50 tph, with the outlet
steam parameters at 67 Ata and 485°C. The variation on the superheater outlet temperature
shall be ± 5 °C. The combustion system of the boiler shall be travelling grate with spreader
stoker. The boiler efficiency, firing 100% mustard stalks, shall be a minimum of 80.0 % on the
GCV basis. The dust concentration in the flue gases leaving the boiler shall be a maximum of
115 mg/Nm³.
The design of the boiler shall be of bi-drum, natural circulation; radiant furnace with water
cooled membrane walls, two-stage superheater with interstage desuperheater and balanced
draft. The boiler shall be top supported and shall be semi-outdoor type. The boiler shall be
capable of a peak generation of 110% of the MCR generation for a period of one (1) hour in a
shift. The operating excess air percentage at the outlet of the boiler shall be less than 30%.
1) Boiler Feed Water
The boiler shall be capable of operating with the following feed water quality
requirements
pH : 8.8-9.2 Oxygen : 0.005 ppm Hardness : 0 Total Iron : 0.01 ppm Total Copper : 0.01 ppm Total Silica : 0.02 ppm Hydrazine : 0.01-0.02 ppm Specific electrical conductivity : 0.5 micro ohms / cm At 25 °C measured after cation exchanger in the H + form and after CO2 removal (max)
2) Steam Purity
The boiler shall be capable of supplying uninterrupted steam at the MCR rating with
• Boiler efficiency at MCR on GCV basis while firing mustard stalks.
• Boiler efficiency at MCR on GCV basis while firing cotton stalks.
• Auxiliary power consumption under MCR operating conditions.
• Steam purity for all operating loads.
• Dust concentration in the flue gases leaving the ESP, while firing rice husk.
The boiler will be of multifuel type, with provision to burn individual biomass with
100%. The Stack shall be of RCC construction, 50 mtr high with total internal
refractory brick lining.
4.4.2 Turbo generator & Auxiliaries
The turbo generator shall be a bleed cum condensing machine. The bleed shall be at 2.5 Ata.
The following shall be the salient design parameters. The speed of the turbine shall be approx.
8000 rpm.
Steam flow at the turbine stop valve at turbine MCR (kg/hr) : 50,000 Steam pressure at the turbine stop valve (Ata) : 64 Steam temperature at the turbine stop valve (°C) : 480 Condenser operating pressure (Ata) : 0.1 Condenser cooling water inlet temperature (°C) : 32.0 Power Factor (lagging) : 0.8 Generation voltage (kV) : 11.0 + 10% Ambient temperature for electrical equipment design (°C) : 45.0 Parallel operation with grid : Required with ASEB grid. Grid voltage : 132 kV Duty requirements : Continuous 8000 hrs. Condenser sizing : 30 tph System frequency : 50 ± 5% Hz Atmospheric Conditions : Dusty Maximum noise pressure levels at 1.0 mtr distance for any : 85 dB(A) Equipment from the Equipment surface shall be equal to or Less than db (A)
4.4.3 Performance Guarantee Tests
The performance test shall be conducted for the following parameters as per ASME PTC 6
and DIN 1943.
• Power output at generator terminals with the inlet steam parameters of 64 Ata and 480°C specified power factor and cooling water inlet temperature of 32°C. Both the extractions shall be at the indicated Normal flow conditions.
• Uncontrolled extraction pressure and temperature with the inlet steam parameters of 64 Ata and 480 °C.
• Auxiliary power consumption under guaranteed conditions.
10 MW Biomass Based Power Plant ABEIL
• Cooling water consumption under guaranteed conditions.
• Maximum temperature rise in the generator windings.
• Heat rate under guaranteed conditions.
4.5 AUXILIARY PLANT AND EQUIPMENT
4.5.1 Biomass Handling
The fuel for the power plant is a rice husk and wood. There will be one separate bunker for
husk and wood. The fuel from the storage is conveyed to the boiler by a combination of belt
conveyors. The system shall have provision for returning the excess fuel to the storage yard
from the boiler. The fuel handling system shall be designed for a capacity of 16 TPH.
Allowable inclination for the belt conveyors is 18°. The belt speed shall be approximately 1.0
m/sec.
4.5.2 Ash Handling
The ash handling system envisaged for the power plant is of two types:
• Gravity system for fly ash
• Pneumatic System. The ash handling system shall be designed to take care of 100% biomass burning. The total
ash quantity generated in the boiler, by the burning of husk is approximately 1875 kg/hr. This
ash content is maximum, as wood will generate only 280 kgs/hr of ash. Ash removed from the
grate is approximately 750 kg/hr and the fly ash quantity is approximately 1125 kg/hr. The ash
density is 120 kg/m³.
The ash received in the grate discharge hoppers will be around 500°C, with ash lumps of size
200 mm maximum. The ash from ash ridding hopper will be dry and powdery in nature and
occasionally with hot solids. The temperature of the ash will be around 200°C maximum.
The fly ash from Electrostatic Precipitator Hoppers will be dry and powdery in nature and
occasionally with hot solids. The temperature of ash will be around 200°C maximum.
The fly ash from the Air Heater Hopper will be dry and powdery in nature and occasionally with
hot solids. The temperature of the ash will be around 250°C maximum.
10 MW Biomass Based Power Plant ABEIL
4.5.2 Cooling Tower
The cooling tower shall be RCC counter flow induced draft cooling tower of capacity of
1800 m³/hr capacity having two (2) cells. The cooling tower shall be designed for a cooling
range of 8°C, and an approach of 5 °C while operating under the atmospheric wet bulb
temperature of about 27°C. The cooling tower shall be of RCC construction. The RCC frame
of the tower shall be integral with the basin. The structure shall be designed for wind and other
load as per IS: 875 and earthquake resistance as per IS: 1893. The cooling tower shall be
carefully sited such that there is no re-entertainment of the vapors in to the cooling tower.
4.5.3 Pumps
The head/flow characteristic of pumps will be such that the head continuously rises with
decreasing capacity until a maximum head is reached at zero flow. Maximum runout flow
should at least be 130% of duty point flow.
The shut off head should be at least 1.1 times the duty point head and should not be more
than 1.2 times the duty point head.
The power curve should be non-overloading type with the maximum power occurring at or
near duty point or towards maximum runout flow.
NPSHR curve should be a continuously rising one in the range of operation, from the minimum
flow in the range to the maximum flow in the range. Required NPSH values shall not exceed
available values over the entire range from minimum to rated flow.
The efficiency curve should be fairly flat in the range of +1% of the BEP flow. The duty point
of the equipment should preferably lie in this flat region, but not at a flow higher than the BEP
flow.
4.5.4 Condensate System
The condensate from the surface condenser and the condensate from the process plant will
be used to meet the complete feed water requirements of the high-pressure boiler. Under the
normal circumstances the make up water for the cycle will be Demineralized water.
10 MW Biomass Based Power Plant ABEIL
4.5.5 DM Plant
The DM plant shall be designed to have single stream with a capacity of 8 TPH. The DM plant
shall be designed based on the raw water analysis furnished elsewhere in this section of this
report. D.M.Tank capacity shall be 36 m3.
The demineralized water quality at the outlet of the DM plant shall be as follows:
• Hardness (ppm) : 0
• pH @ 25 °C : 8.8-9.2
• Conductivity @ 25°C (microsiemens/cm) : 0.05
• Oxygen (max) (ppm) : 0.005
• Total iron (max) (ppm) : 0.01
• Total copper (max) (ppm) : 0.01
• Total silica (max) (ppm) : 0.02
• Residual Hydrazine (ppm) : 0.01-0.02
The raw water at the inlet of the DM plant will be delivered at a pressure of 3.0kg/cm². The
treated water at the outlet of the DM plant will be delivered at a pressure of 3.0 kg/cm².
All vessels shall be designed with adequate free boards. Only seamless pipe shall be used
wherever rubber lining is done. All fabricated vessels shall be designed according to IS
2825.The regenerants like Hydrochloric acid and Caustic Soda shall be stored in bulk in the
DM plant premises, and pumped to the DM plant for regeneration. Manual handling of the
regenerants shall be avoided to the maximum extent.
Adequately sized neutralizing pit shall be provided near the DM plant for collecting the
discharges from the DM plant and effectively neutralizing the same before pumping the waste
to the plant’s effluent treatment system.
4.5.6 Vessels & Heat Exchangers
The design shall be as per ASME Sec. VIII, HEI & TEMA. All heat exchangers and vessels for
steam application shall be designed for full vacuum conditions. The heat exchangers shall be
provided with startup vent connections. The design shall have provision for complete drainage
on both shell and tube sides. The heat exchangers shall be provided with emergency drains,
Tube & Shell side safety valves, and individual bypasses with manual valves.
10 MW Biomass Based Power Plant ABEIL
A minimum corrosion allowance of 1.6 mm shall be provided. The tube bundle shall be of
removable type. The tube material shall be stainless steel, unless otherwise specified in the
specifications.
4.5.7 Tanks
The power plant tanks will have storage capacities as required by design of the systems.
Tanks will be of the closed top type. Tanks will be fabricated in accordance with guidelines
established by API or AWWA as determined by the service. A corrosion allowance of 1.5 mm
shall be provided.
Overflow connections and lines shall be provided where required and will be atleast one pipe
size larger than the largest input line or combination of inputs that can discharge
simultaneously.
Maintenance drain connections shall be provided of an adequate size to facilitate drainage of
tanks within a reasonable time. Manholes where provided on tanks and pressure vessels shall
be of size 450 NB size. Ladders and cleanout doors shall be provided on large tanks. DM
water tank shall be internally lined with natural rubber or painted with three coats of Epoxy
Coating.
4.5.8 Piping
All piping system shall be designed as per ASME B 31.1. In addition statutory requirements of
Indian Boiler Regulations (IBR) shall be complied with for those lines under the purview of
IBR. Stress analysis shall be carried out for all possible operating modes and shall be as per
ASME B 31.1 requirements. Supports, guides, Directional Restraints and Anchors shall be
selected to satisfy all the operating conditions.
1) Pipe Sizing
All piping shall be sized considering the allowable velocity and allowable pressure
drop in the system. The suggested flow velocities of various mediums are
• Superheated : 40 to 55 m/sec
• Saturated steam : 15 to 30 m/sec
• Boiler feed water Pump suction : < 1 m/sec Pump discharge : 2.5 to 4 m/sec
The ash collected in the plenum chamber is extracted by rotary valves and conveyed to a silo
by pneumatic conveyor system.
The ash collected from the air heater and ESP hoppers will be transported to Ash Silo by
rotary valves and pneumatic conveyor.
5.2 TURBO-GENERATOR SYSTEM
5.2.1 Steam Turbine
The proposed power plant will be with one 11 MW turbogenerator. The turbine will be a bleed
cum condensing type and running at a high speed. The generator speed will be 1500 rpm.
Hence, the turbine will be coupled with the generator through a reduction gear unit.
Steam is admitted into the turbine through an emergency stop valve actuated by hydraulic
cylinders. The turbine speed is controlled by an electronic governing system. The turbine
exhaust pressure will be 0.1 ata.
The turbine will be preferably single cylinder, single exhaust, bleed condensing type. All casing
will be horizontally split and the design will be such as to permit examination of the blading
without disturbing shaft alignment or causing damage to the blades.
The design of the casing and the supports will be such as to permit free thermal expansion in
all directions. The blading will be designed to withstand all vibrations, thermal shocks, and
other loading that may be experienced during service and system disturbances. The blades
will be machined from forged bars or die forged and the materials used will be chromium
steels consistent with proven experience and standards.
The glands will preferably of labyrinth type and sealed with it. A vacuum system required by
the design will be provided. All piping and components of shaft seal and vacuum system will
be sized for 300 percent of the calculated leakage. Steam leaving the glands will be
condensed in seal steam condenser. It will be possible to inspect and replace the end seals
without opening the casing and without damaging the thermal insulation.
1) Bearings
The Turbine will be provided with liberally rated hydrodynamic radial and thrust
bearings. The radial bearings will be split for ease of assembly, and of the sleeve or
10 MW Biomass Based Power Plant ABEIL
pad type, with steel shell backed, babbitted replaceable pads. These bearings will be
equipped with anti-rotation pins and will be positively secured in the axial direction.
The thrust bearings will be of the steel backed babbitted multiple segment type,
designed for equal thrust capacity in both directions.
A liberal flow of lube oil under pressure will be supplied to all the bearings for
lubrication and cooling.
2) Lubrication and control oil system
A pressure lubrication and control oil system will be furnished for the turbo generator
unit to supply oil at the required pressure to the steam turbine, gearbox, generator and
governing system. Oil in the reservoir will be maintained at an appropriate
temperature when the TG set is idle by providing suitable electric heaters and
temperature controls.
The oil system will include the following:
• Main oil pump preferably driven by the turbine shaft.
• A 100% capacity AC motor driven auxiliary oil pump arranged to cut in automatically if the oil pressure falls to a preset value. This pump will also meet the requirements during the start up and shutdown.
• A D.C. motor driven emergency oil pump of sufficient capacity to provide adequate lubrication in the event of a failure of the unit AC motor driven pump. This pump also will cut in automatically at a pre set value of the oil pressure.
• Two 100% duty oil filters arranged in such a way by means of transfer valves that it is possible to clean one oil filter while the other is in service with continuous flow.
• Duplex 100% capacity oil coolers with changeover valves.
• An accumulator to maintain sufficient oil pressure, during servo control transients and while standby pump accelerates from idling to full speed.
• Oil storage and settling tank with adequate reservoir capacity, duplicate strainers, level indicators with float switches and alarm contacts, vent and oil mist eliminators.
• Flow and temperature indication for outlet oil from bearings and bearing metal temperature indication for all bearings.
• Centrifugal oil purifier.
3) Oil coolers
The oil coolers will be water-cooled with a duplicate arrangement and changeover
valves. The coolers will be of shell and tube type.
10 MW Biomass Based Power Plant ABEIL
The coolers will be constructed in accordance with TEMA class C. The provided
surface area will be adequate to cool the oil with Inlet cooling water temperature at 35
°C even with 20% of the tubes plugged.
4) Filters
Full flow oil filters will be used downstream of the coolers and will be piped in a
parallel arrangement with a continuous flow transfer valve. Filtration will be 10
microns nominal. Filter cartridges will be designed for minimum pressure drop and
suitable for maximum discharge pressure of the oil pumps.
5) Oil reservoir
The interior of oil reservoirs will be descaled and rust proofed with a permanent
coating. Reservoirs with top mounted equipment will have sufficient rigidity. All
openings for piping will be made dust and waterproof.
6) Oil purifier
A centrifugal type oil purifier will be provided for the removal of water, sediments and
other oxidation products. The purifier will be a separate complete package.
7) Steam Turbine Governing System
The turbine governing system will be electro-hydraulic or electronic designed for high
accuracy, speedy and sensitive response. The electrical/electronic and hydraulic
component of the control system will be selected on the basis of reliability over a wide
range of operating conditions.
All components used will be well proven to assure overall system reliability and will be
designed for easy and quick replacement when necessary. The governor will ensure
controlled acceleration of the turbo generator and will prevent overspeed without
tripping the unit under any operating conditions including the event of maximum load
rejection.
The governor will also ensure that the unit does not trip in the event of sudden
frequency fluctuation in the grid and also sudden grid failure / load through off.
10 MW Biomass Based Power Plant ABEIL
The governor will have linear droop characteristics with a suitable range for stable
operation and will have provision for adjusting the droop in fine steps.
The governing system will have the following important functions:
• Speed control
• Overspeed control
• Load control and speeder gear.
• Steam pressure control
• Master trip for Low Steam Pressure, Low Vacuum, High Vibration, eccentricity, over speed, Differential Expansion etc.
8) Condenser
The condenser will be of non-contact surface type condenser designed as per the
requirements of Heat Exchange Institute Standards for Steam Surface Condensers
and ASME Section VIII division 1. Condenser shell shall be cylindrical made of steel
plate and tubes shall be 19 mm O.D. and 18 BWG admiralty brass. Heat transfer
surface shall have 10% margin for tube plugging over and above fouling factor.
The condenser will be sized to condense the maximum quantity of exhaust steam (i.e.
when the extraction is minimum) with the inlet cooling water temperature at 32°C upto
a maximum of 40°C. (with part load operation).
The condenser design and supply will be complete with the neck, expansion joint,
condensing chamber and tubes, tube sheets, hot well, water boxes, water side, valve,
air removal system and accessories, rupture disc, Teflon padded sliding support,
bolted and hinged water box cover at front and back.
The condenser neck will be suitably designed to reduce the inlet steam velocity to
ensure low-pressure drop and to protect the tubes from impingement of steam.
The condenser will be adequately designed for the external pressure; stiffeners and
bracing wherever required would be provided.
The tubes will be provided with supports to eliminate any serious tube vibration
problems and sagging. The tubes will be expanded into the tube sheets at both the
ends and flared.
10 MW Biomass Based Power Plant ABEIL
The condenser neck will be connected to the turbine exhaust hood with a properly
designed stainless steel expansion bellow which allows free expansion of the
condenser unit without exerting undue thrust on the turbine exhaust hood and
facilitate independent supporting of the condenser on the foundations without
resorting to springs. Manholes will be provided for facilitating inspection of tubes both
at steam and watersides.
The hot well at the condenser bottom will have a minimum capacity of 2 minutes
storage while handling maximum quantity of exhaust steam.
The hot well will be provided with level gauges and connections for condensate
extraction and drain. A suitably designed level control system will be provided, with
provision for alarm tripping etc.
The condenser will be of divided water box design, and the water boxes will provide
easy accessibility to the tubes. It will be possible to clean one section of the tubes with
the condenser load suitably reduced. The circulating water inlet and outlet
connections will be of adequate size to reduce the waterside pressure drop to the
minimum.
The water boxes will be coated with epoxy resin, internally to prevent corrosion from
the cooling water and will be provided with sacrificial anodes.
9) Condenser Air Removal Equipment
One steam operated hogging ejector of single stage will be furnished for the initial
pulling of the vacuum in the system. The capacity will be so as to reach 80 – 90 %
vacuum in 20 minutes time.
Hogging Ejector will be, without any condenser, discharging to the atmosphere
through a suitably designed silencer.
2 x 100% steam operated main ejectors of two-stage twin element type with inter and
after condensers will be provided.
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10) Condensate Extraction Pumps
Two numbers 100% capacity condensate extraction pumps to pump the condensate
from the condenser hot well will be provided.
Both the pumps will be driven by electric motors and the flow will be controlled by
discharge throttling.
The pumps will be of centrifugal, horizontal, single stage type and will be supplied
complete with all valves, inlet and discharge piping with manifolds.
11) Gear Box
The reduction gearbox, if required, between the turbine and the generator will be of
proven design preferably of double helical arrangement with service factor of 1.2
It will be capable of transmitting the maximum rating of the set and be able to
withstand 20% over speed over a period of minimum five minutes. The gearbox will
also be designed for the short circuit condition of the generator.
All bearings of the gearbox will be readily renewable and it will be possible to inspect
the bearings and the gears readily without disturbing the shaft alignment.
Illuminated sight glasses will be provided to inspect the lube oil drain from each
individual bearing. The gearbox design will be as per the requirements of AGMA.
5.3 COOLING WATER SYSTEM
The cooling water is used in the surface condenser for condensing the steam, turbine
auxiliaries for cooling, boiler auxiliaries like feed pump, ID fan etc., for bearing and gland
cooling.
The cooling water after cooling the equipment will be cooled, so that the same water can be
reused again. For this purpose, a wet cooling tower of induced draft type will be used. The
cooling medium in the condenser will be raw water. The cooling water temperature rise in the
systems will be limited to 10 Deg C. The hot return water will be distributed uniformly over the
cells of the cooling tower.
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The raw water from the Canal/ Borewells will be pumped to the cooling towers after suitable
treatment, which will cool the cooling water. For this purpose, two nos (2 x 100%) pumps of
100% capacity each will be provided. The raw water will be stored in a raw water reservoir.
The water will be pumped to the cooling tower fore bay. The water from the fore bay will then
flow to the suction of the cooling water pumps. The cooling water pumps will have the head to
meet the pressure drop in the entire circuit. The cooling water will also be taken to the
turbogenerator, boiler area etc., through pipes of adequate size.
Isolation valves of type gate / butterfly will be provided at different locations, for easy
maintenance. Similarly suitable expansion joints will be provided in the piping, to facilitate
dismantling and also to take care of the misalignments / thermal expansion of the pipes.
The water in the cooling tower basin is prone for algae growth. If algae grow in the cooling
tower water, it will affect the equipment, which are cooled by the cooling water. To prevent the
growth of algae chlorine will be dosed in the water at appropriate quantity. To maintain the salt
concentration in cooling water to acceptable limits, blow down will be given periodically.
5.4 CHLORINATION SYSTEM
The Chlorination system will have two vacuum feed chlorinators, with one as standby. Each
chlorinator will be connected independently to individual evaporators, which in turn be
connected to two chlorine containers. The water for the Chlorination system will be supplied
from the auxiliary cooling tower pump discharge header. The capacity of chlorinators will be
base on a maximum dosing rate of five ppm on the total rate of main and auxiliary cooling
water systems.
5.5 CONDENSATE WATER SYSTEM
The condensate from the surface condenser will be collected in the hotwell. The condensate
will be pumped to a condensate tank by two condensate extraction pumps (CEP). One of the
pumps will be working and other serving as stand by.
The dissolved gases like oxygen etc., present in the condensate, when heated to the
saturation temperature, will dissociate from the condensate and will be vented out. Traces of
oxygen will be removed by dosing hydrazine solution. The make up water for the system will
10 MW Biomass Based Power Plant ABEIL
be DM water. The deaerator will have a storage tank with capacity equivalent to 20 minutes
MCR requirements of the boilers.
The feed water from the deaerator storage tank will be pumped to the economizer by one feed
water pump with one 100% stand by, each of capacity 40 m3/hr.
5.6 Pressure reducing and Desuperheating stations:
One No. PRDS with manual by pass will be provided for supply of low-pressure steam-to-
steam Jet Air Ejector and Turbine glands. One No. Separate PRDS with manual by pass will
be provided for supply of start up steam and pegging steam to deaerator. Pegging steam will
be automatically cut in when pressure of extraction steam from turbine drops below required
pressure.
5.7 DM WATER PLANT
The DM water, which will be used as the make up water, will be produced in the DM Plant.
The capacity of the plant proposed is 8 m3/hr. The DM plant will consist of sand filters,
activated carbon filters, anion and cation exchangers, degasser and mixed bed exchangers.
Two raw water pumps will pump the raw water. The regeneration of the DM plant will be 8
hrs/day. The DM water from this plant will be stored in a Storage tank of adequate capacity.
The acids and alkali required for the regeneration will be sufficiently provided in the plant. The
effluent from the DM plant will be neutralized in a neutralization pit. The outlet water from the
neutralization pit will have a pH of 7.0.
5.8 SERVICE WATER AND POTABLE WATER
The service water is required for general wash, gardening, toilets etc., and the potable water
required for the power plant will be taken from the outlet of the activated carbon filter in the DM
plant.
5.9 CRANES AND HOISTS
Cranes, hoists and monorails will be provided in the following areas of power plant for
maintenance purposes.
Hand operated overhead travelling crane in the turbo-alternator building. Monorails with hoists
for handling boiler feed water pumps located under the deaerator structure, Monorails with
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hoists for handling impellers and motors of ID fans. Monorails with hoists for handling
impellers and motors of FD/SA fans. Monorails with hoists for handling condenser
components.
The TG building would be provided with a hand operated overhead travelling crane of 15 / 5
tones capacity and about 16mts span for maintenance of all equipment in the TG building. The
capacity would be adequate to handle all equipment / component in the TG building including
the generator stator which is the heaviest equipment to be handled. The auxiliary hook would
handle the smaller components in the TG building such as lube oil coolers, ejectors, gland
steam condenser and ejector condenser. This crane will be hand operated.
5.10 COMPRESSED AIR SYSTEM
Instrument air is required for various pneumatically operated control valves in the boiler and
TG systems. The air is required to be supplied at a pressure of 5 to 6 Kg/cm2 (g) at the various
consumption points. Instrument air from the air compressors will be dried by heatless air drier
making use of the hot air from compressor for regeneration of the drier medium (desiccant).
Service air is required for cleaning of various areas of the plant. Accordingly, the service air
connections are proposed to be provided in the Boiler area, TG building, workshop, DM Plant
etc.
Considering the quantity of air required for the power plant, two (2) air compressors will be
required. These compressors will supply the instrument air and the required service air.
Compressors will be of non-lubricated type.
5.11 AIR-CONDITIONING AND VENTILATION SYSTEM
The following areas in the power plant will be air-conditioned.
- The main control room housing the control panels of boiler and TG, switchyard control
panels and auxiliary panel room housing the associated system cabinets. - Instrument maintenance room
The above areas will be air-conditioned using window type/spilt type air conditioners. The
capacity of the air conditioning units will be decided based on the area of the room and heat
load dissipated in the room.
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The following mechanical ventilation systems are proposed to be provided for various
buildings/rooms in the power plant.
- Two (2) axial type power roof ventilation of adequate capacity each for the TG
building. - Two (2) centrifugal type supply air fans of adequate capacity for the switch gear room,
battery room etc., - Suitable number of propeller type exhaust fans in the water pump house, DM Plant,
filtration plant, workshop and stores. 5.12 FIRE PROTECTION SYSTEM
The following systems of fire protection are proposed to be provided for the power plant:
- Hydrant system for the entire plant. - High velocity water spray (HVWS) system for transformers and lube oil tanks. - Carbon dioxide flooding system for the generator of the steam turbine. - Portable fire extinguishers.
The fire protection will basically comply with the Tariff Advisory Committee (TAC)
requirements, enabling rebate in the insurance premium rate.
5.12.1 Reserve Storage
Reserve storage of 350 m3 will be provided in the raw water storage tank with a suitable
partition to cater to the water requirements of the fire protection system. In view of the above,
pump house elevation will also be suitably lowered at the location of the fire water pumps as
compared to the floor elevation at the location of the raw water pumps.
5.12.2 Hydrant System
The hydrant system will comprise the following:
- One motor driven and one diesel engine driven firewater pump. These pumps will take
the suction from the water storage tank. As per TAC regulations, the above hydrant pump capacity will be adequate to cater to the total number of Hydrants provided in the plant.
- Two motor driven jockey pumps (one working and one stand by) each of 10 cum./hr capacity will be provided to keep both the hydrant and HVWS system mains pressurized. These pumps will also take suction from the raw water tank.
- External fire hydrants in all areas of the power plant including boilers, TG, DM Plant, control building, switch yard, canteen, stores, and workshop and administration buildings.
10 MW Biomass Based Power Plant ABEIL
- Internal fire hydrants in all storied buildings and structures such as Boiler platforms, TG building, canteen and administration building.
5.12.3 High Velocity Water Spray System
The HVWS system is proposed to be provided for the transformers and the steam turbine lube
oil tank. Water supply to the HVWS system will be provided by one motor driven pump. Since
the parameters for the HVWS system will be identical to that of the hydrant system, the diesel
engine driven pump described in the hydrant system, can serve as a common standby for both
HVWS system and hydrant system.
The HVWS system will consist of a number of high velocity water projectors mounted on a
pipe network around each transformer and steam turbine lube oil tank. Water supply to each
pipe network from the HVWS system mains will be through a deluge valve. The HVWS
system for the transformers will be of automatic type. In case of fire, quartzoid bulb sensors
mounted around the transformers will automatically actuate the deluge valve on the spray
water line. The HVWS system for the turbine lube oil tank will be manually actuated. Smoke
and heat detectors will be used strategically.
5.12.4 Portable Fire Extinguishers
It is proposed to provide an adequate number of wall/column mounted type portable fire
extinguishers in various areas of the plant including the control room, administration building,
canteen, stores, workshop, pump house, etc., These portable fire extinguishers would
basically be of carbon dioxide and dry power type.
5.12 TECHNICAL DATA FOR MAJOR MECHANICAL EQUIPMENT
5.12.1 Boiler
Number of boilers : One (1) MCR capacity tph : 50 Peak generation tph : 50 Steam pressure at SH outlet Kg/ cm2 (g) : 67 Steam temp. at SH outlet 0C : 485 +/- 5 Feed water inlet temp. 0C : 105 Boiler efficiency on mustard or cotton stalks GCV% : 78.5 Gas temperature at the outlet of AH 0C : 150
Type : Surface, divided Water box Steam flow tph : 30.5 Steam pressure ata : 0.1 Cooling water flow tph : 2100 Tube material 0C : 32 Outlet cooling water temperature 0C : 40
3) Condensate Extraction Pump
Type : Centrifugal Capacity m3/hr : 35 Suction pressure ata : 0.1 Discharge pressure Kg/cm2 (g) : 6.0 Number of pumps : 2
4) Cooling Water System
Cooling Tower:
Type : Induced draft Number of cooling towers : One (1) Capacity m3/hr : 2200 Cooling water supply temperature 0C : 32 Cooling water return temperature 0C : 42 Cooling water return pressure Kg/ cm2 : 0.5 Evaporation loss and blow down % : 2.5 No. of cells : Two (2) Design wet bulb temperature 0C : 27
5) Boiler Feed Pumps
Number of pumps : Two (2) Capacity m3/hr : 40 Head MLC : 1000 Type : Multistage Centrifugal Drive : Electric motor
10 MW Biomass Based Power Plant ABEIL
6) Deaerator
Type : Spray cum tray Capacity tph : 40 Outlet water temperature 0C : 105 Operating pressure Kg/cm2 (g) : 1.0 Design pressure Kg/cm2 (g) : 3.0 Steam inlet pressure Kg/cm2 (g) : 1.5 Oxygen content in the outlet water ppm : 0.007
7) DM Water Plant
Capacity m3/hr : 8 Regeneration hrs/day : 8
8) DM Water Specification
Hardness : Nil Chloride : Nil Silica as SiO2, max. ppm : <0.02 Iron as Fe, max. ppm : <0.01 Conductivity at 20 Deg.C max, : 0.5 microsiemens/cm pH : 9.0 to 9.4 DM water plant will be complete with activated carbon filter, anion, cation exchangers
degassers, pumps, mixed bed exchangers, acid/alkali tank and pumps, raw water pumps etc.,
10 MW Biomass Based Power Plant ABEIL
6 DESCRIPTION OF ELECTRICAL AND I & C SYSTEMS
6.0 GENERATOR
The generator will be rated 11 MW, 11 kV, 50 Hz, 3 pH, and 0.8 pf. The rated speed will be
1500 rpm. The generator winding will have class F insulation. The winding will be star
connected. The star point will be earthed through a resistor to limit the fault current to full load
current. The generator will be air-cooled with an air -water heat exchanger. The generators will
have brushless excitation system.
All the six terminals of the turbo generator winding will be brought out for external connections.
These connections will be taken to the Lightning Arrestor (LA) VT by suitably rated bus bars.
The LAVT will house necessary current transformers, voltage transformers, lightning arrestor
generator neutral grounding resistor, etc. Further connections to the generator circuit breaker
in the 11 kV switchgear will be by means of suitably rated 11 kV cables.
All six terminals of the steam turbine-generator will be brought out of the turbine pedestal wall,
through seal-off bushings. The connections between generator terminals and seal-off bushing
will be by open busbars. Outside the TG pedestal a short run of segregated phase busduct will
be provided on the phase side of the generator to house the current transformers and give
tap-off connections to LA & PT cubicle. This phase side bus duct will be terminated with a
cable termination box for further connection by 11 kV cables upto the 11 kV switchgear.
Similarly, a short run of segregated phase bus duct will be provided on the neutral side to
house the current transformers. The neutral formation and the disconnecting link will be
provided in an adaptor box after the current transformers. A short single-phase bus duct will
be provided between the adapter box and the NGR cubicle.
The generator shall be of closed circuit air-cooled type housed in an IP55 (CACW) enclosure
and driven by steam turbine through a speed reducer. The necessary coupling and coupling
bolts shall also form part of the supply.
1) Stator
The stator frame shall be a single piece consisting of a cylindrical casing of welded plate
construction, reinforced internally in the radial and axial direction by stationary web plates
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making the entire frame perfectly rigid. The stator winding shall be of the double layer lap type
with Class ‘F’ insulation.
2) Rotor
a) The generator rotor shall be forged from a single piece ingot of special alloy steel carefully heat treated to obtain excellent mechanical and magnetic properties and a comprehensive series of ultrasonic examinations on the rotor body shall be done to ensure that absolutely no inadmissible internal defects are present and that the material meets the quality standards.
b) The design and construction of the rotor shall be in accordance with the best modern
practice and shall be fully described in the offer. c) The insulation between turns of field winding shall be consistent class F insulation.
d) The field poles shall be provided with adequate damper windings to ensure stability under
fault conditions and to meet {(I2°C) 2*t} value of 20. 3) Earth Terminal
Two Nos. or more Earth terminals shall be provided. The earth terminals shall be designed to
terminate Galvanized iron conductors. The size shall be as specified in IEC 34-1.
4) Speed Regulation
The moment of inertia of the alternator together with that of the turbine shall be sufficient to
ensure stability and the speed regulation specified in the section- covering turbine for full load.
5) Shaft
a) The generator shaft shall be made of best quality forged alloy steel, properly treated. The
shaft shall be of ample size to operate at all speeds, including maximum over speed
without vibration or distortion and shall be able to withstand short circuit and other
stresses without damage. To prevent the flow of harmful shaft currents damaging the
bearings, suitable shaft earthling shall be provided.
b) A complete set of test reports covering metallurgical strength, crystallographic and
ultrasonic and boroscopic tests performed in each shaft during various stages of its
manufacturing shall be furnished as also the complete specifications of the shaft forging
material and its design parameters such as stresses and critical speed.
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c) The generator shaft shall have a suitably shaped flange for coupling to the
turbine/gearbox shaft. The coupling shall be forged integral with the shaft and the shaft
coupling shall comply with the requirements of IEC for shaft coupling. All coupling bolts,
nut and nut guards for coupling shall be furnished by the vendor. The alignment limit for
the shaft shall be as per the latest NEMA/DIN standards.
6) Space Heaters
Suitably rated heaters shall be installed within the enclosure of the generator. Location and
the maximum temperature of the heaters shall be such that no damage can be caused to any
insulation. Heaters shall be suitable for operation on a single-phase 230 V AC supplies.
A suitable thermostat controlled switch shall be mounted on or adjacent to the stator frame for
the switching off the heaters.
7) Excitation System
a) A brushless exciter shall be used and it shall be mounted on the out board end of the
generator frame. A static voltage regulator shall be included to control the voltage of the
synchronous generator by varying the current supplied to the field. Details of the
equipment shall be furnished along with the bid.
b) A self-excited static excitation system shall be provided. A high speed, fully tropicalised,
printed circuit, drawout type, automatic digital/analog voltage regulator shall be provided.
It should be complete with necessary sensing PT’s, cable entries, cast resin type current
transformer, adjusting rheostats, auto/manual and on/off selector switches. The following
meters of class one accuracy of size not less than 144 x 144 mm shall be provided in the
excitation cubicle and also in the unit control panel.
• Exciter Field Current • Generator Field Current • Generator Field Voltage • Generator Terminal Voltage
c) The excitation system shall be provided with the following features:
• Generator voltage control • Excitation current control • Excitation buildup during startup and fields suppression shutdown.
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• Limiter for the under excited range and delayed limiter for overexcited range. • Feature for parallel operation of the generator with the grid system incorporating
power factor control mode and feature for islanding operation during sudden grid failure.
d) The system offered shall have the following facilities:
• Manual mode of operation • Auto mode of operation • Follow on mode to have smooth transfer from one mode of operation to the other. Auto/Manual changeover facility shall be provided. For manual mode voltage lower/raise
pistol grip type / spring return type switch shall be provided. Following minimum alarms
shall be transmitted to the unit control desk. The excitation system shall have diode
protection relays to detect failure of the Rotating Diodes.
a) Terminal boxes shall be provided to enclose the leads and current transformer. The
terminal boxes shall be adequately designed to accommodate termination of Bus
duct/single core 11 kV XLPE cable per phase and its termination kits. The generator shall
be provided with various RTD’s (temperature sensors) installed various in the stator
winding with leads, brought out to a separate terminal box.
These RTD’s shall be hooked upto the temperature scanner in the control panel.
Necessary vibration transducer, displacement transducers with transmitters shall be
provided which shall be hooked up to the control panel in the control room.
b) Adequately rated neutral grounding resistor / neutral grounding transformer shall be
supplied, the resistor shall be stainless steel edge wound type mounted in shielded safe
enclosure. A current transformer shall be provided for ground fault current measurements
for protection. The rating of the resistor shall be furnished.
c) Necessary surge capacitors and lightning arrestors shall be provided for generator
protection. The surge capacitors shall conform to the latest IS 2834 and shall be rated
10 MW Biomass Based Power Plant ABEIL
0.25 Micro Farad. The capacitors shall be suitable for indoor mounting and shall be
provided with built-in discharge resistor.
6.1 SURGE PROTECTION EQUIPMENT
The surge protection equipment would comprise lightning arrestors with suitable discharge
characteristics to suit the generator insulation level in parallel with suitably rated capacitor for
smoothening the rate of rise of impulse voltage. The lightning arrestors will be located as close
as possible to the generator terminals.
6.2 POWER EVACUATION
The power generated from the proposed power plant will be evacuated at 132 kV through 1
No. 100% capacity transformer.
The generator is earthed through a resistor to limit the earth fault current to acceptable limits
so that generator core is not damaged. Hence this system will be of non-effectively earthed
type.
6.3 11 KV SWITCHGEAR
The power generated from the generator will be fed to an indoor metal clad 11 kV switchgear
through suitably rated cables.
The 11 kV switcher will comprise of draw out type circuit breakers housed in indoor, metal clad
cubicles. The calculated fault level of the 11 kV generator bus is 500 MVA. The circuit breaker
proposed is 750 MVA/40 kA for the generator bus. The breakers will be of either SF6 or
vacuum type.
6.4 POWER TRANSFORMERS
Based on a maximum estimated load of about 12.5 MVA to be evacuated at 132 kV, one No.
12.5 MVA, 11 kV/132 kV, Ynd11, Z = 8% transformers will be provided for interconnection with
the grid. The transformer will be ONAN cooled. It will be provided with OLTC on the HV side
having ± 10% range in steps of 1.25%. The HV neutral will be solidly earthed. The HV side
will be provided with bushings and LV side with cable box.
10 MW Biomass Based Power Plant ABEIL
6.5 132 kV SWITCHYARD
The 132 kV switchyard shall consist of single busbar arrangement, with one incomer from
transformer and one outgoing feeder for connecting the 132 kV line from ASEB. The fault
level at the 132 kV bus works out to 750 MVA. However, as the minimum available circuit
breaker rating at 132kV is 630 A, SF6 circuit breakers suitable for 26.3 kA breaking capacity
will be provided. The isolators will be horizontal center break type with motor operated closing
mechanism. The current and potential transformers will be of oil filled type.
The switchyard will be of outdoor type with galvanized steel lattice structures.
The station auxiliary switchgear will feed the following switchgear / MCCs / Distribution boards:
• Boiler MCC • Cooling Tower MCC • TG MCC • Ash handling system DB • DM Plant DB • Switchyard DB • Lighting DB • Crane DB • Administrator Building / Guest House • Fuel Handling System.
Loads of the power plant auxiliaries and other station loads will be fed directly from the station
auxiliary switchgear.
The main one-line diagram for the power plant, enclosed indicates the auxiliary power
distribution. The various auxiliaries of the power plant would be supplied at the following
nominal voltages depending upon their ratings and functions:
• 415 V, 3 phase, 3 wire effectively grounded AC supply for motors. • 240 V, 1 phase, AC supply for lighting, space heating of motors and panels, single phase
motors, etc. • 230 V, 1 phase grounded AC supply for AC control circuits. • 110 V, ungrounded DC supply for control and indication.
6.6 415 V SYSTEM
The 415V 3 phase, 3 wire power for the 415 V auxiliaries would be obtained from the auxiliary
transformer. The 415 V switchgear would be of metal enclosed design with symmetrical short
circuit rating of 50 kA.
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All the power and motor control centers would be compartmentalized and would be of double
front execution and fully draw-out design with all the circuit components mounted on a
withdrawal sheet metal chassis. The circuit breakers would be air break type. Motor starting
would be direct on-line. Motors rated above 125 kW will be controlled by air break, electro-
magnetic type contactors provided with ambient temperature compensated, time lagged, hand
reset type thermal overload relays, having adjustable settings and backed up by HRC fuses
for protection against short circuits. The switchgear would be located in the control building.
6.7 STATION AUXILIARY TRANSFORMER
The auxiliary transformer would be 1 no. 1.5 MVA 11 / 0.433 kV Dyn11 common for all units.
It will supply power to the 415 V auxiliaries of the power plant STG, CW/ACW system, water
treatment plant, lighting, battery chargers, etc. The neutral of the transformer would be solidly
earthed. The auxiliary transformer would be ONAN type and would be provided with ± 5% off
circuit taps in steps of 2.5% on the HV side.
6.8 CONTROL & PROTECTION SYSTEM
6.8.1 Generator
The following protections are proposed to be provided for the generators:
• Differential protection • Stator earth fault protection • Loss of field protection • Negative phase sequence current protection • Impedance or voltage restrained overcorrect back-up protection • Rotor earth fault protection • Reverse power protection • Over voltage protection • Low forward power protection (for steam turbine generation only) • Under voltage protection • Overload alarm
6.8.2 Capacity 11 kV / 415 V Station Auxiliary Transformer
The following protections are proposed for the station auxiliary transformer:
• 3-pole high set overcorrect protection on H.T. side. • D-pole I.D.M.T overcorrect back-up protection on H.T. side • Single pole instantaneous overcorrect earth fault protection
10 MW Biomass Based Power Plant ABEIL
6.8.3 12.5 MVA, 11 / 132 kV Transformer
The following protections are proposed for the above transformer:
• Differential protection • Directional back-up phase overcorrect protection on HV and LV side • REF protection • Overfluxing protection • Buchholz, oil and winding temperature protection
6.8.4 132 kV Lines
Distance protection would be provided at the generating station side.
6.8.5 132 kV Busbars
High impedance, circulating current type relay scheme with main and check features would be
provided for the 132 kV busbars.
6.9 EMERGENCY POWER SYSTEM
Two Nos. diesel generator sets, 500 kva each, 415 V, 50 Hz will be provided to make
available emergency power supply to the station in case of black-out. The diesel generator
set will be connected to the 415 V switchgear as shown in SLD.
6.10 DIRECT CURRENT SUPPLY SYSTEM
The Direct Current System (DC) is the most reliable source of supply in the power station and
will be used for the control and protection of the power plant equipment.
The DC system will be used for the following:
• Electrical control of equipment and indications on the control panel. • Power supply to the essential auxiliaries of the power plant and turbines in case of AC
power failure. • Power supply to the following services in case of total AC power failure. • Communication system • DC lighting of strategic areas for safe personnel movement. The battery sizing will be done to cater to the following type of loads:
• Momentary load for 1 minute • Emergency load for 2 hours • Continuous load for 10 hours
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Under normal conditions, the battery will be on float charger. The float charger is connected to
a distribution board and meets the requirements of DC load. In case of additional demand of
load or AC supply failure; the battery will meet the requirements of DC loads.
The boost charger will be designed to charger the fully discharged battery in 12 hours before
putting it back on float charge.
A set of two 110V battery blanks (100% standby) of suitable capacity with two float and boost
chargers and a direct current switch board will meet the DC load of power plant. The batteries
would be of stationary lead acid type, complete with racks, porcelain insulators, intercell and
interior connectors. The chargers would be of silicon rectifier type with automatic voltage
control and load limiting features.
6.11 UNINTERRUPTED POWER SUPPLY (UPS) SYSTEM
One battery bank of suitable capacity with associated two 100% float and boost chargers and
invertors would be provided to derive uninterrupted 230 V AC power supply through suitably
rated invertors. The batteries will be sized to cater to the loads for 30 minutes. This power
supply will be used to feed essential services such as control, instrumentation, and
annunciation etc. requiring UPS power. The type of batteries and chargers for the UPS
system would be similar to that described above for the DC system.
6.12 LIGHTING
The power station lighting system would comprise the following:
1) Normal 240 V AC Lighting System
The lighting circuit in the normal 240 V AC lighting system would be fed through 415/433 volts,
3 phase, 4 2wire lighting transformers connected to a 415 V distribution system.
Lighting transformers in each area in the power station would be fed from a convenient 415 V
switchgear/MCC located nearby. About 20% of the lighting fixtures will be connected to
receive emergency AC supply. During failure of normal AC supply, these fixtures will be fed
from emergency AC supply derived from the DG set.
10 MW Biomass Based Power Plant ABEIL
2) Direct Current Emergency Lighting
Direct current emergency lights would be provided at strategic points in the power station, viz.,
near entrances, staircases, the main control room, etc. These would be fed from the station
110 V DC systems and would be off when the normal AC power supply is available. These
would be automatically switched on when the normal AC supply fails.
The proposed illumination levels for various areas are given below:
Area illumination Level Control room 500 lux.
Switchgear / MCC rooms 200 – 250 lux Power house 200 lux. Outlying areas 50 lux. Transformer yard & switchyard 10 – 20 lux. Boiler Area 50 lux Air/Gas compressors house, DM plant 200 lux Workshop 300 lux Canteen 150 lux. Stores 100 – 150 lux. Parking area and cycle stand 70 lux. Battery room 150 lux. Cable vaults 100 lux. Administration building and office rooms 350 lux. Roads 10 lux.
6.13 CABLING
All cables would be selected to carry the load current under site conditions, with permissible
voltage drop. In addition, high voltage cables would be sized to withstand the short circuit
current.
The following type of cables would be used:
For 11 kV generator system: 11 kV unearthed grade, single / multi-core, stranded aluminum
Control, protection, signaling and supervisory cables would be of 650/1100 V grade, annealed
high conductivity stranded copper conductor, PVC / elastomer insulated and overall
PVC/elastomer sheathed. Signaling and supervisory cables would be twisted pairs and
screened wherever required.
The inner and outer sheaths of all the above cables would have fire retardant capabilities.
Cables would be laid in steel ladder type cable trays, suitably supported in the control building,
STG building, other auxiliary buildings. In outdoor areas, cables would be laid in racks/built-up
trenches or would be buried directly underground depending on the environment.
6.14 LIGHTNING PROTECTION SYSTEM
A lightning protection system would be provided as per IS 2309 and Indian Electricity Rules.
The protections would consist of roof conductors, air terminals and downcomers and would be
provided for tall structures such as the STG building.
6.15 FIRE ALARM SYSTEM
A fire alarm system would be installed to provide visual and audible alarm in the power station
for fire detection at the incipient stage. This system would comprise manual call points located
at strategic locations in areas which are normally manned, and automatic smoke and heat
detectors located at important points such as the cable vault, the control room, switchgear
room etc., to detect fire at an early stage, and provide visual and audible alarm.
6.16 FIRE CONTAINMENT
Strategic areas in the plant would be separated by adequately rated firewalls. All openings for
switchgears and cable entry would be sealed by fireproof seals to prevent spread of fire from
one area to another.
6.17 COMMUNICATION SYSTEM
In view of the high noise level in power plants, public address system is not recommended.
For effective communication in the plant, automatic dial type telephones would be set up,
having the following features:
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6.17.1 Inter-communication Telephones
This system would comprise a telephone exchange and an adequate number of dial type hand
set stations located in soundproof cabins with suitable flashing indication on top of it to
indicate incoming call.
The handsets in the control room would be provided with priority service facility to enable them
to have immediate access to any of the handsets even if the handsets are already engaged. A
private automatic exchange for communication with outside parties would also be provided.
6.17.2 Walkie-talkie Sets
Walkie-talkie sets would be provided for key personnel. This would, however require special
permission from the statutory authorities.
6.18 SAFETY EARTHING SYSTEM
A Safety earthling system consisting of a buried mild steel conductor earthling grid would be
provided for the power plant transformer yard, switchyard and other outlying areas. These
would be connected to the earth grids in various buildings. The buried earthling grid would be
further connected to earthling grid would be further connected to earthling electrodes buried
under ground and located at representative points.
The earth electrodes will be 40 mm diameter and 3000 mm long G.I rods and the main earth
conductors will be 75 mm x 12 mm flats. The earth conductors when buried will be of mild
steel and galvanized wherever exposed to atmosphere.
6.19 INSTRUMENTATION AND CONTROL
6.19.1 General
The instrumentation & control (I&C) system proposed to be provided for the power plant would
facilitate centralized automated and safe control of the power plant comprising of the Boilers,
TG and their auxiliaries, condensate system and the cooling water equipment. The I&C
system would be designed to ensure maximum efficiency, reliability, safety and availability so
that optimum plant control could be achieved with minimum staff.
The I&C system basically comprise of the following:
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• Functionally distributed microprocessor based I&C system • Hard wired annunciation system • Analytical Instruments • Control desks, panels and system cabinets • Power supply systems • Local instruments
6.19.2 Distributed Instrumentation & Control System (DCS)
The functionally distributed microprocessor based I&C system will have a hierarchically
distributed structure and will integrate the various plant functions/systems such as
measurements system, closed loop control system, open loop control system, sequence of
events record, data base system, fault monitoring diagnosis, man machine interface etc.,
The above I & C system will have complete redundancy at processor level and communication
level. At the sensor level, triple redundancy will be provided for all critical closed and open
loops and single sensors will be provided for all other open and closed loops. For critical
analog controls, Freudian selection from three measurements will be adopted while for critical
open loops triple sensors with two out of three logic will be provided. Considering the high
reliability of presently available processors, no further redundancy by way of hard-wired back
up systems is proposed for open loops.
1) The DCS shall include the following main subsystem
a) Control and Data Acquisition Subsystem for monitoring and control of process parameters like flow, temperature, pressure, level, power, current, voltage, analytical and status.
The system shall also platform the plant supervisory functions like performance calculations, utility display, operator guidance message displays, logs, historical storage and retrieval etc., as specified in the subsequent chapters.
b) Sequence & interlock, safety sub-system for monitoring and executing sequence
operation, plant shutdown, interlocks and plant start-up. c) Operator / Engineer interface sub-system for operator guidance message displays
and remote control, for tuning, configuring, programming and maintaining the system. d) Redundant Communication sub-system for interconnecting all the sub-system. e) The closed loop sub-system for continuous action on valves or other mechanical
devices which alter the plant operating condition to bring the plant parameters to stable condition.
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f) The open loop sub-system for operation on various inter related drives of plant safely, automatically and sequentially with the interlock and protection functions being available all the time under all conditions of operation to avoid mal-operation and to increase the plant availability.
The system shall communicate with the temperature scanners, other system using PLC in
serial communication mode using MODBUS protocol mode for monitoring/interlocking
purpose.
Functionality of these subsystems described in the corresponding chapters of the
specification.
Programmable Logic Controllers (PLC) or other special control devices shall be incorporated
in the subsystems.
These controllers shall be full informationally compatible with the DCS and shall allow an
information exchange through a mutual DCS/PLC Data Highway and corresponding gateways.
The list of alarms shall be sufficient for providing safe plant operation.
2) DCS General Characteristics
a) Process Controller Fire Characteristics:
The word “process controller file” refer to any combination of microprocessor
associated memory, data acquisition and output devices which can be configured to
perform a set of control and/or logic function, data acquisition, calculation and
complex analog & discrete strategies.
Means shall be provided to ensure the loss of power supply of any controller file does
not result in loss of memory requiring manual reconfiguration, without error, during a
power outage.
b) The minimum design features shall include but not limited to the following:
Redundancy shall be provided to the processing controller unit, power supply, I/Os for
critical signals and communication modules.
Redundancy shall also be provided for the data highway connections and serial
interfaces.
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Power supply used for interrogation with field devices shall also be redundant.
All input and output modules shall be short circuit proof.
The system shall be arranged so that the failure of any monitoring device or control
components or spurious intermediate grounding in the signal path shall not open the signal
loop nor cause the loss or malfunction of signal to other devices using the same signal and
unrelated control loops.
Necessary grounding facilities shall be available with the system; to take care of the earthling
related problems.
The design of the control system and the related equipment shall adhere to the principle of
fail-safe operation at all system levels. Fail-safe operation signifies that the loss of signal, loss
of excitation or failure of any component shall not cause a hazardous condition and at the
same time occurrence of false trips.
Upon restoration of power, the system will initialize itself to the established configuration and
operation. The contractor shall provide detailed explanation on system features provided for
power failure recovery.
If a transmitter fails for an analog input value exceeding preset limits, means shall be provided
to create an alarm and initiate appropriate protection action, such as transfer to manual or any
other protective action. It shall be possible to assign high or low limits to each analog input;
should a transmitter exceed either limit it shall be possible, through configuration, to transfer
the affected protections of the system to manual.
The system shall be able to withstand the electrical noise and surge as encountered in actual
service conditions.
Detailed marshalling cabinets shall be provided on as required basis for termination of all
analog and digital inputs to the system and all analog and digital outputs from the system.
A minimum of 20% spare terminals and a minimum of 20% additional modules shall provided
in excess of the total requirement of the system design.
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The system shall include self-surveillance and monitoring facilities, diagnostic features, tools
etc., so that a failure / malfunction shall be diagnosed automatically, and giving the details to
the operator stations.
- Closed loop control execution shall be done within 250 msec. - Sequence control/interlocks scan time shall be within 100 msec. - All the open loop shall be scanned at the rate of less than 1 sec. - DCS and PLC sampling time shall be adjusted after selection of the DCS and PLC
types. - Provision shall be included to produce a clear text, hard copy record of the detailed
configuration of each file. 6.19.3 Annunciation System
All abnormal operating conditions leading to unit shutdown will be simultaneously annunciated
on the distributed microprocessor based control system as well as on the conventional alarm
fascia units mounted on the control panel.
Additionally, group control function (i.e. related to the sub-system as a whole or the main
equipment) and individual equipment failure will be annunciated on the alarm fascia in the
control panel. All individual or subsidiary control function failure will be annunciated on the
DCS.
For safety and protection logic's, contacts will be taken only from primary sensing devices,
wherever feasible. Alarm contacts will be derived from the measurement signal using limit
value monitors.
6.19.4 Control desk and panel
The main control room in the control building will house the necessary control desks and
panels. The various I&C system cabinets will be housed in the auxiliary control room adjacent
to the main control room. The programmers console, computer cabinets, disc cabinets,
printer's etc., will be located in the computer room.
The control desks will incorporate CRTs with associated keyboard, illuminated push button for
pumps, dampers, valves, TG control devices etc., auto manual stations, control switches, push
buttons and synchronizing equipment for the boiler and TG. The control panels will be of
simplex free standing type and will house indicators / recorders for all controlled parameters
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and certain important non-controlled parameters, annunciation windows for all trip conditions
and critical process conditions and ammeters for all large capacity motors.
1) Operator Stations
The operator main interface to the control system shall be through operator stations
consisting of color CRT’s mouse/trackball and keyboards. In addition certain software-
assigned and hard-wired recorders shall be installed if required. The operator station
shall be suitable for Industrial Duty.
Non-disk based Man-machine interface is preferred.
2) Capabilities
Capabilities of a minimum 100 process graphic displays will be provided. This figure
does not include detail display, group display, trend display, alarm list and
maintenance displays.
3) DCS Highway Communication Requirements
A redundant network communication link (data highway) shall be provided. The data
highway shall provide the means by which process I/O, management information and
control information is accessible to the operator interface and to all other control files
and other highway devices. In the event of failure on one link, communication shall
continue without disturbance to on-going operation.
6.19.5 Power Supply
The complete I&C system would basically be designed to operate on 110 V AC supply which
would be provided from the uninterrupted power supply (UPS) system incorporating necessary
batteries, chargers, inverters etc., Certain other voltages required for the system, e.g. 24 V DC
power supply required for contact interrogation, 48 V DC required for certain electronics cards,
etc., will be derived from the 110V AC power supply made available from UPS system.
6.19.6 Local Instruments
In addition to the above, all necessary local instruments such as pressure, temperature and
level gauges, pressure, temperature, level and flow switches etc., will be provided in the power
plant to enable the local operator to supervise and monitor the equipment operation.
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1) Temperature Instruments
All temperature elements shall be provided with thermowells fabricated out of bar
stock of minimum SS 304 material. Any pipe lines less than 4” nominal bore shall be
increased locally to 4” size to install thermo wells.
Local temperature gauge shall be generally mercury in steel filled type, weatherproof,
with 150 mm dia dial gauge size, with shatterproof glass. Filled type with capillary
tubing shall be minimum of SS 304 with stainless steel flexible armoring. The gauges
shall have accuracy of ± 1 % FSD.
Duplex type thermocouples or RTD shall be used wherever required.
Adequate design care has to be taken to ensure thermal conductivity between
thermowell and temperature measuring element.
Thermocouples shall be as per ANSI MC 96.1 and shall be of 14 AWG magnesium
oxide insulated grounded type. For temperature above 800 dec. the sheath shall
made of Inconel 600. For temperatures above 800 dec. the sheath shall be made of
SS 316. The thermocouples shall be selected as follows:
a) Copper – Constantan (ISA-TYPE T) for ranges : - 200 to 200°C b) Chromel – Constantan (ISA-TYPE E) for ranges : - 200 to 600°C c) Chromel – Alumel (ISA – TYPE K) for ranges :- 600 to 1200°C
RTD shall be three wire type with platinum element with 100 ohms resistance at 0
dec. calibrated as per DIN 43760.
Twin element sensors, if used, shall have two separate conduit entries.
2) Pressure Instruments
Pressure gauges shall have an accuracy of ± 1% of FSD. These shall be weather
proof with dial size of minimum 150 mm and shall have features like screwed bezels,
externally adjustable zero, over range protection and blowout discs.
Pressure gauge sensing element shall be minimum of SS 316 and moving parts of SS
304. For important applications, 250 mm dial size shall be used. The glass shall be
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shatter proof. Bidder shall provide snubber / siphon along with the pressure gauges
wherever required.
Pressure transmitters – smart type with a minimum turndown ratio of 1:30 with local
indicator shall be electronic capacitance type or piezoelectric resistance type with
minimum of SS 316 element material and with a over range protection of minimum
130% of range.
Direct mounted pressure switch shall have element diaphragm or below of minimum
of SS 316 material with ½” NPTF connection.
3) Level Instruments
All gauge glasses shall be steel armored reflex or transparent type with body and
cover materials of carbon steel as a minimum and tempered imported borosilicate
glass.
Differential pressure transmitter shall be used for level measurement.
Level switches shall generally be external ball float type with flanged head.
For remote level indication of drum, a separate level transmitter shall be employed
which will be connected to a digital indicator with LED and barograph display.
4) Flow Instruments
Flow measurement shall be with flow nozzles for Main steam flow and thin plate
square edge concentric orifice plate mounted between a pair of weld neck flanges of
minimum 300 pounds ANSI rating with flange taps for other measurements. The
material of the orifice plates shall be SS 316.
Meter runs shall have sufficient straight line as per BS-1042.
DP type flow transmitter shall normally be electronic capacitance / piezo – resistive
type and smart type with a turndown ratio of minimum 1:30
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5) Control Valves
- Control valves shall normally be Globe type. Other types like butterfly valves, ball valves, angle valves, 3 way valves, etc., shall be selected as per service.
- Minimum body and flange rating of control valves shall be as per piping class. - Body material, as a minimum, shall be as per piping specifications. - Valve seat leakage shall be as per ANSI B 15.104. - Leakage of shut down valves shall be Class VI, as a minimum and leakage
for control valves shall be Class IV. - Valve positioners wherever used shall be side mounted force balance
pneumatic type. - For electronic instrumentation, I/P converter shall be used along with
pneumatic positioners. - Self actuating regulators for flow, pressure and temperature shall be used
where loads are constant and shall be of precision controls. The power cylinders shall be double acting piston modulating type, trunnion mounted,
with linear cam characteristics and provision for reversal action. The piston rod shall
be hard chrome plated high strength steel. The driving equipment shall be in “STAY
PUT” mode on air failure. The power cylinders shall be supplied with positioners, limit
switches and position transmitters.
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7 ENVIRONMENTAL IMPACT AND POLLUTION CONTROL
The type of pollution, which affects the environment, emanating from the power plant can be classified
as follows:
• Air pollution • Water pollution • Thermal pollution • Noise pollution
7.1 THE POLLUTANTS GENERATED FROM THE POWER PLANT ARE
* Dust and particulate matter in the flue gas * Fly ash from the hoppers * Furnace bottom ash * Effluent from water treatment plant * Sewage from the plant
CONTROL METHODS FOR AIR POLLUTION
7.2.1 Dust and particulate matters
The pollution control norms stipulates a maximum dust concentration of 115mg//N.cu.mt. The
proposed power plant will have an Electrostatic Precipitator (ESP), which will separate the
dust from the flue gas and has an efficiency of 98%. The dust concentration is the flue gas
leaving the ESP will be maximum 115 mg/Nm3.
The dust concentration level in the chimney will be periodically monitored. Corrective steps will
be taken, if the concentration is not as per the acceptable limits.
7.2.2 Sulphur-di-oxide and Nitrogen-di-oxide
The main fuel in the proposed plant is Bio Mass, which does not have significant Sulphur in it.
Hence, the Sulphur dioxide will not be produced. However, the stack height will be as per the
local pollution control board stipulations. The nitrogen-di-oxides are not produced in firing.
7.2.3 Fly Ash and Bottom Ash
The ash collected from the bottom of furnace (bed ash) and the ash collected in the air heater
hoppers and ESP hoppers are taken to an ash silo through a series of conveyors. The ash
from the silo will be disposed off to farmers, who can use the ash as manure for the crops.
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CONTROL METHODS FOR WATER POLLUTION
1) Effluents from Water Treatment Plant
The water drained from the water treatment plant will have to be treated so that the water let
out is neutral (pH 7.0). To achieve this the water drained from the water treatment plant is
pumped to a neutralization pit. The neutralization pit will have acid resistant brick lining.
Depending on the quality of water collected in the pit, either an alkaline medium or acidic
medium will be pumped into the pit to neutralize the water.
2) Boiler Blowdown
In order to maintain the solid concentration in the boiler feed water, two types of blow down
are employed in the boiler. One type is continuous blow down and the other intermittent blow
down.
The blow down water will be at a temperature of 100 0C. The quantity of blow down will be
around 1.5 tph. This water can be taken to the effluent ponds, where it will get cooled
naturally.
3) Sewage from the Power Plant Buildings
The sewage from the various power plant buildings will be taken to a common septic tank
through trenches. The sewage from the septic tank will be disposed off through concrete
trenches. As the sewage is taken in trenches the soil will not get contaminated.
7.3 CONTROL METHODS FOR THERMAL POLLUTION
The water used in the surface condenser to condense the steam will be cooled in a cooling
tower of either induced or forced draft type. The water let out from the cooling tower will have
a temperature very close to the ambient.
CONTROL METHODS FOR NOISE POLLUTION
The major source of noise pollution in the power plant power plant is from the following:
Rotating equipments like ID, FD and SA fans
- Feed pumps - Boiler and superheater safety valves - Start up vent - Steam turbine
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7.4.1 DG Sets
As per OSHA standards, the sound level from the rotating equipments shall be 85 to 90 dBA.
The rotating equipments will be designed to achieve this.
The start up vent, safety valve outlets and the DG sets will be provided with silencers to
reduce the noise level to the acceptable limits.
The power house building will be constructed suitably to keep the noise level within the
acceptable limits.
Promoters are aware of their social obligations and will be establishing an effluent treatment
plant to treat its liquid effluents.
The Pollution Control Board norms for air, water and sound is given below:
Tolerance Limits for Discharge of Trade Effluents
Characteristics
Tolerance Limits for discharge of Trade Effluents
Inland Surface Water On land for Irrigation
Suspended solids (mg/lit.) 100 200
Dissolved solids-Inorganic (mg/lit.) 2100 2100
PH value 5.5-9.0 5.5-9.0
Temperature (0C) 40 at the point of discharge
45 at the point of discharge
Oil and grease (mg/lit.) 10 10
Biochemical Oxygen Demand (BOD) for 5 days at 20 0C
30 100
Chemical Oxygen Demand (COD) (mg/lit.)
250
Chloride (as CL) (mg/lit.) 1000 600
Sulphates (SO4) (mg/lit.) 1000 1000
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Ambient Air Quality Standards
Characteristics Concentration (mg/m3)
SPM So2 CO NOX
Industrial and mixed use 500 120 5000 120
Residential & Rural 200 80 2000 80
Sensitive 100 30 1000 30
Emission Standards for Boilers
Capacity of Boilers (tons/h) Particulate Emission Limits (mg/Nm3)
Less than 2 1600
2 to 15 1200
More than 15 150
This requirement is applicable for boilers using any type of solid fuel. In the case of industries
where particulate emission control are adopted to the limits prescribed, the stack height can
be relaxed to H = 74 Qp0.27, where Qp = Particulate emission in Tons per hour.
Permissible Noise Levels
Exposure Duration per Day Sound Level dB (A)
8 90
6 92
4 95
3 97
2 100
1 102
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8. POWER PLANT LAYOUT
8.1 CRITERIA FOR THE POWER PLANT LAYOUT
The general criteria for the power plant layout are as follows:
a. The main steam piping to the turbogenerator shall be as short as possible. This is to avoid excessive pressure and temperature drop in the steam line, which would affect the turbine performance. Also, the material used will be alloy steel, which is very costly.
b. The length of the HT cables from the TG hall to the switchyard shall be minimum. c. The length of the slat conveyor from the storage area to the boiler etc. has to be
minimum. This is to reduce the auxiliary power consumption and the cost of the equipment.
d. Fuel storage yard shall be far away from the equipment so that there will not be any
dust nuisance. e. The switchyard, ash handling area and Fuel storage handling area has to be
accessible by roads. 8.2 BOILER LAYOUT
The layout for the boiler 1 x50 tph will be on the eastern side of the Plant. The feeding system
for fuel will be located in the boiler front. The operating floor for the boiler will be concrete and
at a elevation of 5 Mts. from the ground level. The boiler will be provided with 800 mm width
floors, wherever required.
The boiler will be top supported. The economizer and the air heaters will be located just after
the boiler bank one over the other. The air heater will consist of two blocks. Suitable space will
be provided and provision made for cleaning of the air heater tubes. The boiler feed water
pumps will be located below the deaerator storage tank, at the ground floor of TG building.
The feed water control station will be located in the boiler operating floor. The chimney height
will be decided based on the local pollution control norms.
8.3 TG BUILDING LAYOUT
The TG building will be located adjacent to the boiler area. The TG building will be sized to
accommodate the 11 MW turbogenerator and its auxiliaries. The turbine will be located at an
elevation of 6 Mts. from ground level. The building will be steel structure with regular roof with
side cladding. The floors will be made from pre cast slabs, which gives better appearance and
10 MW Biomass Based Power Plant ABEIL
the installation time will be less. The condenser will be located just below the TG at ground
level. The condenser extraction pumps and the evacuation system will also be located at the
ground floor. The TG building will be provided with a Crane for lifting the turbine parts for
maintenance.
8.4 ELECTRICAL AND CONTROL ROOMS
Both the electrical and control rooms will be located in the TG building. The battery charger
room and office will also be located at this floor at elevation 6 Mts. The location of the control
room will be such that the boiler and the turbine will be clearly visible from the control room.
8.5 FUEL STORAGE AREA
Power plant shall have a planned fuel storage yard to store the fuel quantity
8.6 ASH HANDLING SYSTEM
The ash handling system consists of scrapper conveyor, belt conveyors and screw conveyor.
The ash from the travelling grate hopper, plenum chamber, air heater hopper and the ESP
hoppers will be collected and conveyed to a main ash silo which will be located close to the
chimney.
8.7 SWITCH YARD
The biomass power plant shall have a well planned power evacuation switchyard of 132 kV.
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9. PROJECT SCHEDULE AND IMPLEMENTATION
9.0 PROJECT IMPLEMENTATION
9.1 PROJECT SCHEDULE
The schedule for the implementation of the biomass power project of Amrit Bio Energy and
Industries Ltd Jagi Road in Mayong Circle of Marigaon district in Assam with a capacity of 11
MW is enclosed. The project schedule indicates the various activities, which includes
Engineering, Detailed Engineering, Procurement, Erection and Commissioning of the project.
The project needs 18 months from the date of financial closure and placement of orders for
critical items like, Boiler and Turbine.
9.2 PROJECT MANAGEMENT
Engineering Management system, is a functional strategy developed to meet the tasks of the
engineering division keeping in view the overall project and the company’s objectives.
It is a set of planned and well-defined systems and procedures for each activity and sub-
activity for engineering tasks to complete the project from feasibility, conceptual design,
detailed engineering upto commissioning and operation of the plant. The following major
constituents of the Engineering management systems are being used for the execution of this
project:
Division of Responsibility & Authority, which defines the role and responsibilities against the
tasks identified for the engineering services, project engineering and Quality Assurance &
Inspection services in various disciplines such as Civil, Mechanical, Electrical, Controls and
Instrumentation.
Engineering and Monitoring System covers identification of various Engineering activities and
sub-activities both pre-award and post-award of the main plant equipment for this project.
The monitoring of the progress reports and look ahead planning is made on the basis of
Scheduled dates against the actual date of completion of the activities or anticipated dates to
complete the activities for every month.
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Vendor Drawing Control System provides the status reporting and monitoring for Vendor
submitted drawings, which give the clue to identify the vendor drawings, falling in different
approval categories, drawings which are over due for submission by the vendor, drawings
which are pending for transmittal of the comments / distribution etc. This is very important from
the point of vendor progress monitoring.
Drawing Control Procedure elaborates how to control drawings received from the vendor or
developed in-house. The system identifies how the drawings are to be processed and who has
the authority to approve these drawings / documents and transmittal of the drawings to the site
office concerned, project consultant and to the vendor.
9.2.1 System for Feed Back
This project has got a group of field engineers, which will perform the engineering tasks at site
office and support the engineering group concerned at the Head office. The engineering
group is the focal point for all engineering issues and the field problems pertaining to
engineering. They also receive drawings and documents and distribute amongst the various
departments of the project, provide any clarification or modification of any nature and give the
feed back during construction and commissioning stage of the project. They are also
responsible to generate project drawings and data to AS-Built information.
9.2.2 Computer Aided Design
The use of Computer Aided Design (CAD) for development of engineering design and
drawings is being emphasized by the company. Presently almost all the engineering tasks are
performed using CAD with the software programs already available and developed within the
company.
9.2.3 Assurance of Engineering Quality
With the use of standardized document, model technical specification, design guidelines and
checklist, the required engineering quality is possible to achieve.
Cost Control: In order to have control on the overall cost of the project, the project is split into
no. of packages and the cost is worked on the basis of the price data obtained from various
vendors, as well as on the basis of the trends of the cost variations in the present day market.
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Time Control: This is achieved during project planning and monitoring system. Monitoring is
done at every place - Regional office, Consultant’s office and the Site office.
9.3 CONSTRUCTION MANAGEMENT
9.3.1 Power Plant and Facilities
Site activities of project group shall be carried out as per Consultants, Construction
Management Manual advice prescribing systems and procedures, their scope of
responsibilities, inter-relationships as outlined in the various chapters.
Organization tasks and framework for construction management has been organized in four
distinct headings namely:
a) Construction Management Tasks.
b) Construction Management Organization. c) Functional Boundaries & Scope of Work. d) Construction Management Interface. The Construction Management Tasks cover the following: -
i) Infrastructure development ii) Construction execution supervision ii) Safety and security iv) Planning, Scheduling, Reviewing and Control. v) Field quality surveillance vi) Site contracting
vii) Material Management viii) Cost control ix) Liaison with external agencies x) Personnel administration and welfare xi) Finance and Account.
9.4 CONSTRUCTION MANAGEMENT ORGANISATION
Construction Organization at project site is headed by a project manager, a senior executive
from the plant assisted by a consultant engineer from the consultant side. The project
manager is assisted in carrying out site functions by functional heads viz.
Head of project construction, planning, scheduling and project co-ordination. Head of Personnel Management, which includes finance and accounts.
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The construction, erection and commissioning is carried out by the contractors with the
technical supervision from the Consultant / Customer Engineers in association with the
representatives of equipment manufacturer to the satisfaction of the plant engineers. The tools
and plants for construction are brought by the contractor.
The functional boundaries and scope of work cover the following areas: -
i) Construction planning and scheduling, ii) Civil construction
iii) Equipment erection iv) Site contract group, which provides centralized services at site for awarding work
contracts. v) Material management functions cover activities of material planning, procurement,
storage issue etc. vi) Site service is a centralized service group which provides and maintains all common
construction facilities, tools, plants and construction utility services. vii) Personnel and Administration group at site is guided by the HRD division at Head
quarters and it is responsible for man power planning, recruitment etc. viii) Finance & Accounts.
9.5 INFRASTRUCTURAL FACILITIES & CIVIL SYSTEM
The existing biomass power plant has well developed infrastructure facilities and civil for
structures like office building, power plant buildings and other storage yards etc. Separate
infrastructure facility is not required for this power plant.
9.6 QUALITY ASSURANCE & INSPECTION
The procedure for the Quality Assurance and Inspection is evolved by the consultant in co-
ordination with the power plant engineers. In order to ensure high reliability and better
performance, quality assurance programs have been developed for all packages. For this
purpose, bid documents for all contract packages stipulate that the bidders have to submit
their own quality assurance programs for manufacturing and field activities.
They include identification of
a) Quality organization. b) Documentation control. c) Procedure for purchase of materials, parts, components and selection of
subcontractors, services including vendor analysis, source inspection, raw material inspection etc.
d) Control and testing of calibration, testing of measuring and testing equipment. e) Handling, storage and delivery. f) Maintenance of records to meet all the contractual requirements.
10 MW Biomass Based Power Plant ABEIL
All the contractors are required to develop such QA programs after the review of all technical
specification and contract requirements. The QA programs of the vendors are taken into
consideration during bid evaluation by the consultants. At the time of finalization of the
agreement with the successful vendors, a detailed quality plan setting and the quality practices
and procedures, relevant standards and acceptance level for all the components of all the
equipment will be mutually discussed and agreed to.
Further, consultant / client witnesses tests / inspection etc as per the customer hold points
(CHP) to be selected by the consultant in quality plans, beyond which the work will progress
only with the consent of the consultant. Apart from this, the quality surveillance of the system
and procedures of the contractor’s quality control organization will be carried out for monitoring
the implementation status.
In addition, the consultant / customer will carry out quality audits on the systems and
processes for the areas of manufacture and field activities to determine the effectiveness of
implementation and to ensure conformance to code, contract and procedure requirements.
Control of quality in the field right from the stage of material receipt till final commissioning will
be effected by the field quality control group. This group will be independent of actual
execution schedules and costs and will function under technical guidance from the
consultant’s QA group.
9.7 MAN POWER TRAINING & PLACEMENT
The existing power plant is having proper Organization structure. The existing biomass power
plant has well trained technicians and other labors. This new plant needs some more
technicians and labors for its operation and maintenance.
10 MW Biomass Based Power Plant ABEIL
10 MW Biomass Based Power Plant ABEIL
10 MW Biomass Based Power Plant ABEIL
10. OPERATION AND MAINTENANCE
The proposed Organization structure for the operation and maintenance (O&M) of the power plant is
presented in the exhibit. In order to ensure a high level of performance of the power plant, it is
proposed to induct experienced O&M engineers from the very beginning of the project.
10.1 BASIC STRUCTURE OF THE O&M TEAM
The basic structure and the broad functional area within the O&M organization would be as
follows:
The Plant Manager would have the primary responsibility for the O&M of the power plant. The
organization will comprise of four broad functional areas viz. Operation, maintenance,
technical and administration. The basic duties covered under each of these functional areas
would be as follows:
10.1.1 Operation
• Operation of main generating equipment, fuel handling systems, water systems including water treatment plant, switch yard and other auxiliary plant.
• Except for the Power Station Superintendent all other operating personnel would work on three shift basis.
• Shift personnel manpower planning for key areas has been generally done on 3+1 concept, to take into account leave taken by shift personnel.
• The day to day operation of the power plant will be controlled by the Manager who will be assisted by the Control room operators and shift engineers.
10.1.2 Maintenance
• Maintenance of mechanical and electrical plant, control systems, buildings, roads, drainages and sewage systems etc.,
• Operation of the plant workshop, planning and scheduling maintenance works and deciding the requirement of spare parts.
• The Plant Manager will be assisted by departmental engineers, who take care of the maintenance aspects of all mechanical, electrical and I&C requirements.
• Trained technicians will be employed to assist the maintenance group in day to day maintenance of the plant
10 MW Biomass Based Power Plant ABEIL
10.1.3 Administration
The main responsibilities of this department will be as follows:
• Purchase
• Plant Security
• Liaison with local labor officers
• Stores management
• Finance & Accounts
• Medical Services
• Secretarial & Clerical
• Transport services
• HRD and Training
10.2 FACILITIES TO BE EXTENDED TO THE EMPLOYEES
The number of employees required for the proposed power plant will be around 40. The
personnel required for administration and finance & accounts also will be provided. The
following facilities will be provided in the power plant:
• Administration building and technical office
• Construction offices and stores
• Time and security offices
• First aid and fire fighting station
• Canteen and welfare center
• Toilets and change rooms
• Car parks and cycle/scooter stands. 10.3 STATION OPERATION PHILOSOPHY
The power generated from this plant is exported to ASEB Grid. Necessary software and
hardware features are required for effective operation and maintenance management system.
Software system manages and provides the information needed to manage daily operations,
improve labor productivity, reduce maintenance costs, and monitor preventive and predictive
maintenance programs.
Through more effective scheduled and preventive maintenance, the costs associated with
emergency breakdowns can be greatly reduced. This includes savings from reduced payroll
overtime, fewer defective products and reduced down time losses from disrupted production
schedules.
10 MW Biomass Based Power Plant ABEIL
10.4 STATION MAINTENANCE PHILOSOPHY
The based power plant maintenance philosophy is based on the following aspects:
10.4.1 Ordinary Maintenance
Ordinary Maintenance, which covers routine checking and minor and refurbishment activities
to be performed according to operating manuals on component / equipment in operating
conditions.
10.4.2 Emergency Maintenance
Emergency Maintenance, which is a corrective maintenance to be performed when a
significant failure occurs. To minimize forced outages duration, an effective Emergency
Maintenance must be supported by:
A proper stock of spare parts.
Permanent monitoring and diagnostic systems for main components.
10.4.3 Maintenance Plan and Scheduled maintenance
Scheduled maintenance is carried out according to maintenance plan, which should be
discussed and optimized according to the needs of the customer/client.
The maintenance plan is based on scheduled outages for the following components:
• Boiler
• Steam Turbine
• Alternator
• Switchyard equipment
10.5 MAINTENANCE MANAGEMENT SYSTEM
The maintenance of this plant will be carried out as per the above philosophy. This system
aims at maximizing the availability of the plant, while ensuring minimum maintenance cost and
safety of the plant and personnel.
Meetings are convened by various departmental Heads to accelerate the decision making
process and to lay down the priorities and guidelines for maintenance work to be taken up.
10 MW Biomass Based Power Plant ABEIL
10.6 SPARE PARTS MANAGEMENT SYSTEM
The primary objective of spare part management system will be to ensure timely availability of
proper spare parts for efficient maintenance of the plant without excessive build-up of non-
moving and slow moving inventory.
The spare parts management system for this project will cover the following areas:
• Proper codification of all spares and consumables.
• Spare parts indenting and procurement policy.
• Ordering of critical mandatory and recommended spares.
• Judicious fixation of inventory levels and ordering levels for spare parts based on experience.
• Development of more than one source of manufacturer/ supplier Whenever practicable.
10.7 AVAILABILITY OF O & M MANUALS
All contracts include provision of at least 6 sets of detailed O & M manuals, which will be
distributed to all departments concerned well in advance from the commissioning date of the
power plant to avoid problems in preparation of commissioning documents as well as proper
installation and commissioning procedures of various equipment.
10.8 SPECIAL TOOLS AND TACKLES
All contracts will include the provision for supply of one set of all types of special tools and
tackles, which are required for installation, commissioning and proper maintenance of plant
and equipment.
10.9 OPERATION REQUIREMENTS
With the completion of the official hydraulic test of the boiler, the pre-commissioning and
commissioning activities start. Pre-commissioning checks of the individual equipment will lead
to safe commissioning of the equipment. Installation procedure and commissioning procedure
as stipulated in the O & M manuals supplied by the various equipment suppliers shall be
carefully followed. Wherever possible, it is advisable to keep the vendor’s representative at
site for commissioning the auxiliary equipment of the power plant.
However, the boiler, turbo-alternator and other critical equipment have to be commissioned by
the supplier itself, as the performance guaranties lie with them.
10 MW Biomass Based Power Plant ABEIL
Controls and Instrumentation system along with alarm and trip interlocks should be put into
operation to safeguard the equipment as well as the operating personnel.
10.10 CHECKLISTS AND PROTOCOL
A detailed checklist for the various equipment, supplemented with the checklist submitted by
the supplier shall be drawn and logged for future reference. This will also form part of the
plant’s base history / datum.
Whenever an equipment in commissioned, the important parameters of that particular
equipment should be observed for a period of eight hours and the readings shall be logged as
per the log sheets. These activities shall be performed in the presence of the customer /
consultant and a protocol shall be signed.
10.11 ORGANISATION LEVELS & GRADING OF POSITIONS
Every position in an organization is graded within these decision-taking bands based on a
short description mentioned below. These grading levels range from A Band (unskilled labor)
to E- Band (Top Management). The definitions for the classification of different positions are
as follows:
A-Band Basic elementary decisions where the options and alternatives are limited.
Information required by the worker is limited, simple, and easy to understand. It mainly requires unskilled labor and training requirements are minimum.
B Band Operational decisions in a logical sequence of elements Experience and
practice is essential for taking decisions in this band. Training normally takes a few months.
C Band Process decisions in a systematic sequence of operational activities.
Problems have to be diagnosed and the best solution form a range of alternatives needs too be selected and implemented. A broad spectrum of intensive formal education, as well as experience, is required for these jobs.
D Band Interpretative decisions by middle Management. E Band Strategic decisions by Senior Management.
10 MW Biomass Based Power Plant ABEIL
. STATUTORY CLEARANCES REQUIRED
The following are the statutory clearances required for the proposed power plant of ABEIL at Jagi
Road in Mayong Circle of Marigaon district in Assam. Details of Approvals are given in the notification,
which is enclosed.
11.1 Approval from AEDA
ABEIL shall file an application with AEDA for sanction of project as per the Government of
Assam notification of power projects. ABEIL, will also need to enter an agreement with AEDA
as facilitator.
11.2 Tariff Fixation from AERC
ABEIL Ltd,should file an affidavit with AERC for obtaining the tariff.
11.3 Power Purchase Agreement with ASEB
After obtaining the approval from AEDA, and ASEB, ABEIL,need to enter Power Purchase
agreement with ASEB.
11.4 Approval for Parallel Operation
Approval of the Government of Assam through ASEB for parallel operation of generating set
with ASEBGrid, shall be sought. Scheme has to be approved by ASEB Inspectorate.
11.5 Pollution Control Board
Initially consent to establish to be obtained from the Assam State Pollution Control Board for
the air pollution, water pollution and noise pollution. The source of pollution and the control
methods proposed are discussed in the chapter, “Environmental Impact and Pollution Control”.
On commissioning, consent to operate need to be obtained from Pollution Control Board.
11.6 The Land Use Clarification Clearance From Govt. of Assam
Approval for the layout and buildings of the power plant is required from the Town Planning
Department of Govt. of Assam.
10 MW Biomass Based Power Plant ABEIL
11.7 Approval for the Electrical Installation
The electrical installations like transformers, switch yard equipment etc., shall be approved by
the Chief Electrical Inspector, for the safety features, location etc.
11.8 Boiler and Pressure Part Components
The approval from the Chief Inspector of Boilers, Assam is required for the installation and
operation of the boilers, steam and water piping.
11.9 Ground Water Board
The make up water for the power plant is proposed to be pumped from the nearby take and
borewell available in the site. Clearance from the Central Ground Water Board is required for
using the ground water.
11. 11 Irrigation Department
It is better to have the permission from Irrigation department for drawal of water from the
canals.
11.12 Information to MNES
Ministry of Non Conventional Energy Sources, (MNES) extends the capital subsidy. Promoter
need to apply to MNES through AEDA, after obtaining the loan sanctioned from Financial
Institution. MNES needs the following documents enclosed to their application and check list:
a. Detailed Project Report b. Project Approval from AEDA c. Power Purchase Agreement with ASEB d. Consent to Establish from Assam State Pollution Control Board. e. Sanction Letter from Financial Institution f. Appraisal Report from Financial Institution
MNES gives the principal approval initially, and sanctions the Capital subsidy after
commissioning. MNES is yet to issue administrative approval.
11.13 Duty Exemption:
Govt of India had issued the notification, exempting the Excise Duty and Custom Duty for
setting up these plants. Govt of India Notification is already given in Chapter 1. Promoter
should take advantage of this. Suppliers of the equipment are need to be taken, Duty
Exemption Certificates from MNES.
10 MW Biomass Based Power Plant ABEIL
12. COST ESTIMATES
12.1 GENERAL
ABEIL is planning to install 11 MW Biomass based Power Plant at Jagi Road, Mayong Circle,
Marigaon District. As this plant is situated in Assam, transportation charges, erection and
commissioning charges are more compared to the other parts of India. Even Govt. of Inia
gives the special incentives for the North Eastern States.
This chapter deals with the estimates of the total cost of the power project. The estimate is
also based on the budgetary offers received from the various manufacturers for the major
equipment and in house cost data compiled for power plants. Contingency provision has been
made, but not the escalation, as the project is expected to be implemented within short period.
Ministry of Finance, Govt of India, had issued the notification No: 33/2005 – Central Excise
dated 8th Sept 2005, exempting the custom duty and excise duty for the plat and machinery
required for biomass based power plants. Hence, the project cost is exclusive of these duties.
This chapter deals with the estimates of the total cost of the power project. The estimate is
also based on the budgetary offers received from the various manufacturers for the major
equipment and in house cost data compiled for power plants. Contingency provision has been
made, but not the escalation, as the project is expected to be implemented within short period.
The cost of the power plant given in this chapter, covers all the costs associated with the
construction of the plant, and includes the civil construction cost, cost of equipment for power
generation, cost of auxiliaries and utilities. The total cost is arrived at by adding to this cost,
the pre operative expenses inclusive of project design and engineering, start up and training
expenses, interest during construction and the margin money for working capital.
Table 12.1 to 12.4 gives the details of the project works cost estimate including Civil,
Mechanical and Electrical cost. Table 12.5 to 12.9 gives the details of the estimate of the
project cost which includes the contingency, preoperative expenses including the IDC and
working capital margin. The table also gives the drawl of the term loan during the project
construction period and the calculation of the IDC is based on that. It is presumed that the
10 MW Biomass Based Power Plant ABEIL
term loan disbursement is proportional to the amount of the equity invested. Table 12.10 gives
the consolidated details of the total cost of the project.
12.2 LAND AND SITE DEVELOPMENT
This company is planning to procure the land with the help from Revenue Officials of Morigaon
District. The proposed site is just behind 132 kV Substation of Jagi Road , Mayong Circle. .
Table 12.1 – Land and site Development
(Rs. Lakhs)
Particulars Amount
Cost of Land to be acquired 45.0
Cost of leveling and development 10.0
Cost of laying of roads
Internal roads for the Factory 5.0
Approach road connecting the Main Road 5.0
Internal roads for the Township 5.0
Cost of fencing/compound wall 15.0
Cost of Gates 2.0
Total 87.0
12.3 CIVIL AND STRUCTURALS
The civil work includes the earthwork and concrete work for the power house building,
equipment foundations, tanks, cooling tower basin etc. The cost of laying of in plant roads,
fencing drains and sewers is also included as part of civil cost. The RCC/structural steel work
for the turbogenerator building is also included under the heading of Civil Works cost. No piling
has been envisaged for the building as well as for equipment foundations and only open
foundations are considered.
The civil work quantities and the cost of civil are only estimates and will have to be suitably
modified and firmed up after the equipment supply is finalized and adequate data regarding
the loading dimensions of equipment are available from the manufacturers and suppliers
during the engineering stage, and also on the actual soil conditions encountered at different
stages of construction. The estimates given here are based on the soil bearing capacity of 35
Tones/Sq. mtr at 3.5 meter depth.
10 MW Biomass Based Power Plant ABEIL
The total cost of civil works including equipment foundations, buildings, cost of land
development, roads, and miscellaneous foundations etc is estimated at Rs. 317.78 Lakhs.
Table 12.2 Civil Works Cost Estimate
Sl. No.
Description Unit Quantity Rate Rs.
Cost (Rs. Lakhs)
7.0 Power plant building
7.1 Excavation m³ 2015 120 2.42
7.2 Backfilling with approved earth m³ 1495 108 1.61
7.3 PCC m³ 195 4560 8.89
7.4 RCC grade M20 including formwork m³ 371 6000 22.23
7.5 Reinforcement Steel T 36 48000 17.47
7.6 Brick work m³ 520 2400 12.48
7.7 Windows, doors etc. m² 260 2160 5.62
7.8 Plastering m² 13351 108 14.42
7.9 Flooring m² 1729 600 10.37
7.10 Painting m² 8671 84 7.28
7.11 Structural Steel T 87 43200 37.63
7.12 Grating m² 104 1800 1.87
7.13 Plumbing LS 1.50
7.14 Precast RCC Roof Slabs, 125 mm thick LS 1.50
7.15 Weathering Course LS 1.50
7.16 False ceiling LS 1.00
8.0 Foundation for boilers, turbogenerator, transformers & other equipment 0
8.1 Excavation m³ 2925 120 3.51
8.2 Backfilling with approved earth m³ 2470 108 2.67
8.3 PCC m³ 135 4560 6.17
8.4 RCC grade M25 including formwork m³ 527 6000 31.59
8.5 Reinforcement Steel T 60 48000 28.70
8.6 Micellaneous (Embedments, Foundations etc.) LS 2.20
9.0 Cooling tower basin, raw water tank, pumps and miscellaneous foundations 0
9.1 Excavation m³ 1300 120 1.56
9.2 Backfilling with approved earth m³ 1040 108 1.12
10 MW Biomass Based Power Plant ABEIL
9.3 PCC m³ 91 4560 4.15
9.4 RCC grade M20 including formwork m³ 455 6000 27.30
9.5 Reinforcement T 35 48000 16.85
10.0 RCC Chimney and foundation
10.1 Excavation m³ 1950 120 2.34
10.2 Backfilling with approved earth m³ 1560 108 1.68
10.3 PCC m³ 137 4560 6.22
10.4 RCC grade M20 including formwork m³ 644 6000 38.61
10.5 Reinforcement T 59 48000 28.08
10.6 Embedments, flanges, ladders & platforms T 20 50400 9.83
10.7 Refractory lining millboard etc. LS 6.00
11.0 Switch Yard Civil Foundation
12.0 Temporary stores, office building, garage, etc. LS 4.20
13.0 Misc. civil works for conveyor supports, ducitng supports, fuel handling system etc. LS 16.80
14.0 Factory buildings for auxiliary services like water supply, laboratary, workshop LS 14.00
15.0 Administrative buildings & guest house LS 25.20
16.0 Misc. non-factory buildings like canteen, time office, change room LS 11.20
17.0 Garage / Parking LS 2.80
18.0 Architect fees LS 35.00
TOTAL 475.58
12.4 MECHANICAL AND ELECTRICAL WORKS
The project cost estimate includes the cost of all other auxiliary systems of the power plant,
like the cooling water system consisting of cooling tower, and the pumps, DM water system,
compressed air system. AC and ventilation system, fire fighting etc. Steam piping, high
pressure and low pressure, feed water piping, cooling water piping and all other piping of the
power plant.
The 132 kV transmission lines for evacuating power are also considered in the electrical
estimates. The cost of the generator transformer for stepping up the generated voltage to the
exportable voltage level, the distribution transformers for meeting the power requirement at
415 level for power plant, the power control center for feeding power to the plant, the cables
10 MW Biomass Based Power Plant ABEIL
and bus ducts, complete earthling of the plant and lighting are included in the works cost
estimate.
Cost towards the plant erection, testing and commissioning have been included in the
equipment cost indicated. Also the cost estimates given in the report are inclusive of the taxes
and duties, freight and insurance.
The cost of the two years spares is estimated to be two percent of the mechanical and
electrical equipment cost which is included in the cost of the equipment included in the works
cost estimate.
The total cost of the mechanical and electrical works is expected to be around
Rs. 3236 Lakhs
Table 12.3 Machinery Cost including Electricals
(Rs. in Lakhs)
Equipment/ Machinery Amount
Steam Turbine & generator
(11 MW bleed cum condensing)
1050.00
Boiler & BOP
Boiler 1200.0
DM plant 30.0
Cooling water system and piping 60.0
Fuel handling system 140.0
Ash handling system 45.0
EOT Crane 25.0
Substation 210
Plant electricals 50.0
Cooling tower 60.0
Fire protection 25.0
Air conditioning & Ventilation 40.0
Utilities like water & comp.air 50.0
Erection 80.0
Transmission lines system 121.0
Miscellaneous like weigh bridge, chippers etc., 50.0
Total 3236.00
10 MW Biomass Based Power Plant ABEIL
Table 12.4 Electrical Cost Estimation
Sl. No Description Quantity Amount in Lacs
1 11 KV Panel 1 37.00
2 NGR and Surge arrestor 1 5.00
3 33 KV SF6 Breaker 1 8.00
4. 33 KV control & Relay Panel 1 8.00
5 33 KV Isolator 2 4.50
6. CT 1 1.00
7. PT 1 1.00
8. Power Transformer – 12.5 MVA 1 80.00
9. Auxiliary Transformer – 1.25 MVA 1 20.00
10. MCC Panel 1 7.50
11. 110 Volts Battery set 1 2.50
12 110 Volts Battery Charger 2 10.00
13 DCDB 1 1.00
14 UPS 1 1.00
15 Cables 1 10.00
16 Lighting materials 1 2.00
17 Earthing 1 2.00
18 Steel Structure in tonnes 5 3.50
19 Erection Charges - 6.00
Total 210.00
12.5 CONTINGENCIES
A provision of about 5% of the costs of the civil and structural work, mechanical and electrical
equipment and other costs has been provided towards the contingencies, during the
construction of project. This contingency provision works out to Rs. 220.92 Lakhs.
10 MW Biomass Based Power Plant ABEIL
Table 12.5 Contingencies
(Rs. in Lakhs)
Particulars Cost Contingency Provision
Amount
Site development 87.00 5% 4.35
Buildings 475.58 5% 23.78
Plant & Machinery 3236.00 5% 161.80
Misc. Fixed assets 92.00 10% 9.20
Pre-Operative Expenses 435.75 5% 21.79
Total 220.92
12.6 NODAL AGENCY’S REQUIREMENT
AEDA is the nodal agency to give approval to this project. They will also act as coordinators
for this project. As the policy is not yet announced, provision for nodal agency fee is taken as
Rs. 2.00 lakhs.
12.7 MISCELLANEOUS FIXED ASSETS
The cost of Miscellaneous fixed assets is estimated at Rs.92 Lakhs based on the budgetary
estimate received from the suppliers. The details are as under:
Table 12.6 Miscellaneous Fixed Assets
Particulars Amount Rs in Lakhs
The laboratory equipment 30.00
Workshop equipment 30.00
Vehicles 20.00
Furniture 5.00
Office equipment 7.00
Total 92.00
12.9 WORKING CAPITAL MARGIN
The working capital shall meet the requirements of raw material costs and the receivables.
70% will be bank finance and the 30% will be the margin money to be capitalized. The
financial analysis takes into consideration an interest rate of 12.25% for working capital
financed by bank. Working capital requirement in first year is Rs. 424.09 Lakhs. The total
10 MW Biomass Based Power Plant ABEIL
requirement of margin money for working capital is estimated at Rs. 106.02 Lakhs on the
basis of raw material for 180 days and the debtors for 60 days in first year. On the above
basis, the total working capital loan requirement for the first operation year is estimated at Rs
318.07 Lakhs. In third year working capital requirement increases to Rs.576.50 lakhs and the
requirement of working capital margin money increases to Rs. 148.49 Lakhs.
Table 12.7 Working Capital
(Rs. in Lakhs)
Particulars / Years 1st year 2nd year 3rd year 4th year 5th year
Bank Finance Required 318.07 373.70 432.38 445.47 458.97
12.9 INTEREST DURING CONSTRUCTION (IDC)
The interest during construction period is capitalized to calculate the project cost. The IDC is
calculated considering the phasing of the capital expenditure given below.
12.9.1 Phasing of Capital Expenditure
The project construction period is 18 months from the date of ordering the main equipment.
The following gives the phasing of the capital expenditure on quarterly basis from the date of
ordering of the boiler and the turbo generator, which contributes the major expenditure.
Interest on loan for the construction period is taken as 12.25%. Interest during construction is
rounded off to Rs.412.00 Lakhs.
Table 12.8 Phasing of Capital Expenditure & IDC
(Rs. in Lakhs)
Quarter Capital Expenditure
Equity Term Loan Interest till the date of Completion
1 1421.48 355.37 1066.11 171.90
2 947.65 236.91 710.73 96.61
10 MW Biomass Based Power Plant ABEIL
Quarter Capital Expenditure
Equity Term Loan Interest till the date of Completion
3 710.74 177.68 533.06 63.97
4 710.74 177.68 533.06 47.97
5 473.82 118.45 355.37 21.32
6 473.82 118.45 355.37 10.66
Total 4738.27 1184.57 3553.80 412.43
It is assumed that, equity will be 30% of the project cost, i.e. Rs1421lakhs
While calculating the IDC, it is considered that the drawl of long term loan from Financial
Institution will commence simultaneously with the bringing in the equity.
12.10 PRE OPERATIVE EXPENSES
Pre-Operative Expenses are estimated on the basis of expenditure incurred during the
implementation of the project. This is inclusive of the amount to be paid to AEDA, front end
fee, and the fees to be paid to obtain the statutory approvals including the registration of
company. Detailed engineering and consultancy charges are not included in the preliminary
expenses. Implementation period is around 18 months. The details of pre operative expenses
are as under:
Table 12.9 Pre Operative Expenses
(Rs. in Lakhs)
Particulars Amount
Nodal Agency's Fee 2.00
Travelling 10.00
Ireda Application Fee 0.00
Front end Fee 0.00
Company Incorporation Charges 8.00
Deposits 0.00
Trial run Expenses 3.75
Interest during the construction period 412.00
Total Pre-Operative Expenses 435.75
IREDA does not take the registration fee, and front end fee for the projects implemented in North
Eastern states. Hence this amount is not considered.
10 MW Biomass Based Power Plant ABEIL
12.11 Detailed Engineering Fee
A provision of Rs. 70.00 Lakhs has been made towards the fees for detailed Engineering.
12.12 TOTAL PROJECT COST
Project Cost : Rs. 4738.27 Lakhs
It is assumed that 30% of the above total project cost, i.e. Rs.1421Lakhs will be met from
equity. The loan component of the project cost works out to Rs. 3317Lakhs.
Table 12.10 Summary of Project Cost Estimate
(Rs. in Lakhs)
Particulars Amount
Land & Site Development 87.00
Buildings 475.58
Plant & Machinery 3236.00
Mice. Assets 92.00
Detailed Engineering 70.00
Contingencies .22092
Preliminary Expenses 15.00
Pre-Operative Expenses(incl.IDC) 435.75
Margin Money for Working Capital 106.02
Total 4738.27
10 MW Biomass Based Power Plant ABEIL
13. FINANCIAL ANALYSIS
13.1 GENERAL
Financial Analysis carried out with the assumption of finance from IREDA. IREDA gives the
special interest rate reduction of 1% from the regular states biomass based power plant
interest rate and they don’t charge registration fee and Front end fee.. Assumptions for
financial analysis is given below:
A. Debt equity ratio is 70:30 B. Interest rate 12.25% C. Repayment period of 9 years including 2 years moratorium D. Project completion period – 18 months E. Repayment of loan in 28 quarterly installments F. Biomass(rice husk) Price: Rs. 1500.00 per tonne in first year and increases by 5% per
annum 13.1.1 This section of the report gives the financial analysis of the power project using rice husk as
fuel and the proposed tariff calculations(based on the ‘Cost Estimates’under section 12) for
sale of power to the grid.
13.2 MODE OF FINANCING
13.2.1 The total project cost with the interest during construction and working capital margin is
estimated to be Rs. 4738 Lakhs as given in ‘Cost Estimate’. Since the project fulfills the
norms of renewable energy biomass based projects, it is expected that the project will get the
eligibility of 70% of the project cost as long term loan.
13.2.2 Thirty percent (30%) of the total project cost i.e. Rs. 1421 Lakhs will be brought in as the
equity for the project by the Management of the power plant. The balance of Rs. 3317 Lakhs
will be mobilized as long term loan from financial Institutions.
13.2.3 It is assumed that this loan amount will be repaid in Seven (7) years in 28 equal installments
and there will be an initial moratorium of two (2) years on the loan repayment. An interest rate
of 12 % is considered on the term loan, and it is assumed that the interest payment and the
loan repayment will be quarterly.
13.2.4 This Power Plant will be located at Jagi Road, Morigaon District.
10 MW Biomass Based Power Plant ABEIL
13.2.5 The project envisages no foreign exchange out flow, since all the equipment are assumed to
be bought from indigenous suppliers and foreign exchange if any will be organized by the
suppliers of the equipment.
13.3 PLANT OPERATION
ABEIL is planning to operate the plant for nearly 330 days. Installed capacity is 11 MW. The in
house consumption for power plant will be around 1 MW. It is estimated that, this plant will be
in a position to export around 10 MW to the grid. The plant load factor is taken as 90%
13.4 Raw Material Requirement and cost:
On an average biomass requirement is around 1.25 tonnes per generation of 1 MWh. Plant
will be operating for nearly 330 days, i.e. 7884 hours, including annual maintenance.. The
capacity utilization assumed is 90% from the first year itself. This assumption is mainly for
financial analysis. The price of rice husk is taken as Rs.1500 per ton as per current rate with
an escalation of 5% per annum.
13.5 SALABLE ELECTRICITY
13.5.1 The Gross generation of power in the new power plant will be 11000 kW. Out of this, around
10% of power will be consumed in the power plant, i.e.1000 kW. The balance power of 10000
kW can be supplied to the grid.
This exportable power with a plant capacity utilization of 90% will be supplied to the ASEB
grid. This will work out to (7884x10000)kwhr i.e.78.84 million units per annum.
13.5.2 The power generated is proposed to be sold to the ASEB at present, as ASEB is directed by
Govt. of Assam.
13.5.3 UNIT CAP PRICE OF ELECTRICITY
The Ministry of Non-Conventional Energy Sources, have recommended a price of Rs. 2.25 per
kWh, for the base year 94-95. They have also recommended an escalation of 5% on the Unit
price every year. While, many SEBs have not yet fully implemented these recommendations,
Govt. of Rajasthan had issued the notification indicating the base price of Rs.3.52 for the year
2004-05.
Since ASEB is having a deficit of 221 MU after the contractual purchases in 2006-07, it has to make up
the deficit by purchasing power from Power Traders at a high rate of Rs.3.57(avg) as indicated under
10 MW Biomass Based Power Plant ABEIL
clause 2.7 earlier.We are assuming that, Assam State Electricity Regulatory Commission will give the
cap rate of sale of biomass based power of at least Rs.3.50 per unit upto a limit of 200 million units in
the year 2007-08 to make up the deficit of power.
13.6 OPERATION AND MAINTENANCE COST
The repairs and maintenance cost for this project has been assumed as Rs.61.56 Lakhs in
first year with escalation of 5% per annum. The salaries and wages of the operation and
maintenance personnel of the power generation plant is separately considered (Refer table
enclosed to the section on Manpower and Training) and the same have been worked out as
Rs.68.36 Lakhs, including a provision for contract labor service charges.
Table 13.1 Price escalations
Expenses Amount Escalation per year
Repairs and Maintenance 61.56 5%
Salaries and Wages 68.36 5%
Consumables 15.00 5%
13.7 ADMINISTRATION, OVERHEADS AND SELLING EXPENSES
The Cost included under this head is Rs. 75.28 Lakhs including Rs. 25.00 Lakhs for insurance.
This also includes the general administrative expenses.
Table 13.2 Administration, Overheads and Selling Expenses
Expenses Amount Escalation per year
Managerial and Administrative salaries 45.28 10%
Selling and Other Expenses 5.00 0%
Insurance 25.00 0%
Both Operation & Maintenance and Administration Overheads/Insurance are considered under O&M Expenses in the calculations for generation cost.
13.9 TAXES ON GENERATION AND SALES
No expense under this head is considered since this is not applicable.
13.10 ESCALATION PROVISION FOR VARIOUS COSTS AND EXPENSES
10 MW Biomass Based Power Plant ABEIL
An escalation of 5% on the salaries and wages, 5% on the administrative expenses and 5%
on the cost of utilities is considered in the financial analysis. An escalation of 5% is considered
on the cost of fuel in the financial analysis.
13.11 DEPRECIATION
A straight line depreciation rate of 3.6% for the plant and machinery as provided in the Gazette
for a life span of 25 years is considered in the financial analysis. The depreciation based on
the above rates works out to Rs.170.57 Lakhs for a full year.
13.12 CAPITAL SPARES
1% of gross fixed assets amounting to Rs.Rs.47.38 lacs is taken as capital spares
per annum.
13.12 GENERATION COST and PROPOSED TARIFF
The annexed schedule gives the estimate of cost of production of electricity, for ten (10) years
operation from plant commissioning and the proposed tariff for sale of power to the grid after
considering a 14% ROI. Plant capacity utilization of 90% has been considered from first year