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Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
Glossary Abbreviations
GIZ Deutsche Gesellschaft für Internationale Zusammenarbeit GmbH
SREDA Sustainable and Renewable Energy Development Authority
SBI Supplied by the Industry
BDT Bangladeshi Currency (Taka)
IRR Internal Rate of Return
NPV Net Present Value
CNG Compressed Natural Gas
Cub. M Cubic Meter
CPP Captive Power plant
°C Degree Centigrade
ECM Energy Conservation Measures
kW Kilowatt
kWh Kilowatt hour
kVAR Kilo Volt Ampere Reactive
kVA Kilo Volt Ampere
kCal Kilo Calorie
MT Metric Ton
NG Natural Gas
PF Power factor
REB Rural Electrification Board
ROT Rule of Thumb
SEC Specific energy consumption
V Volt
A Ampere
hr Hour
CO2 Carbon Dioxide
sft Square Feet
GEG Gas Engine Generator
DG Diesel Generator
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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EXECUTIVE SUMMARY Purbani Composite Textiles Ltd. uses diesel from Bangladeshi Oil Co., natural gas from Titas Gas and Electricity from Rural Electrification Board
(REB) as its primary energy sources. The company reports to use 31,638 litres of diesel, 10.845 million cubic meters of natural gas for gas
generators and 0.889 million cubic meters of natural gas for production process and 533,105 kWh of electricity from REB during January 2017-
December 2017.
Table 1: Base year breakdown of energy consumption, cost and CO2 emission.
Total 31,638 11,734,748 533,105 450,258 100.0% 117,634,726 1,470,434 100.0% 25,451.4
The energy assessment of Purbani Composite Textiles Ltd identified energy efficiency cost savings worth BDT 43.289 million per year including
housekeeping measures against a proposed estimated investment of BDT 109.987 million. The savings amount is about 37% of the total energy
cost. An investment grade energy assessment in the plant identified the following opportunities for energy cost savings3:
2 Reduction of CO2 is taken as 56 kg/GJ for Natural Gas, 67.2 kg/GJ for Petrol, 74 kg/GJ for Diesel, 77.6 kg/GJ for Furnace oil, 95 kg/GJ for Bt. Coal and 168.8
kg/GJ for Grid Electricity. Source: CLEER tool: https://www.cleertool.org/Support 3 All calculations are based on present energy tariff prevailing during the time of visit. Rate of USD was taken BDT 80 per dollar.
4 Reduction of CO2 is taken as 56 kg/GJ for Natural Gas, 67.2 kg/GJ for Petrol, 74 kg/GJ for Diesel, 77.6 kg/GJ for Furnace oil, 95 kg/GJ for Bt. Coal and 168.8 kg/GJ for Grid Electricity
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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SL No.
Energy Conservation Measures (ECM)
Investment Cost Without subsidies
Annual Savings % share of Identified Savings
Payback Period (Years) BDT
USD Natural
Gas in Cub. M
Electricity in kWh
GJ tCO2 (MT/yr)4
BDT GJ BDT
14 Provide closed loop control for soft water pump
5 Low, medium and high investments have been considered as USD $ 0-10,000, $10,001-50,000 and $50,001+ respectively. 6 Reduction of CO2 is taken as 56 kg/GJ for Natural Gas, 67.2 kg/GJ for Petrol, 74 kg/GJ for Diesel, 77.6 kg/GJ for Furnace oil, 95 kg/GJ for Bt. Coal and 168.8 kg/GJ for Grid Electricity
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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Table 4: Medium Cost Energy Conservation Measures with Summary7
7 Low, medium and high investments have been considered as USD $ 0-10,000, $10,001-50,000 and $50,001+ respectively. 8 Reduction of CO2 is taken as 56 kg/GJ for Natural Gas, 67.2 kg/GJ for Petrol, 74 kg/GJ for Diesel, 77.6 kg/GJ for Furnace oil, 95 kg/GJ for Bt. Coal and 168.8 kg/GJ for Grid Electricity
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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Table 5: High Cost Energy Conservation Measures with Summary9
SL No.
Energy Conservation Measures (ECM)
Investment Cost Without subsidies
Annual Savings % share of Identified Savings
Payback Period (Years) BDT
USD Natural
Gas in Cub. M
Electricity in kWh
GJ tCO2 (MT/yr)10
BDT GJ BDT
1 Replace clutch type sewing machines with servo type sewing machines
9 Low, medium and high investments have been considered as USD $ 0-10,000, $10,001-50,000 and $50,001+ respectively. 10 Reduction of CO2 is taken as 56 kg/GJ for Natural Gas, 67.2 kg/GJ for Petrol, 74 kg/GJ for Diesel, 77.6 kg/GJ for Furnace oil, 95 kg/GJ for Bt. Coal and 168.8 kg/GJ for Grid Electricity
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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Table 6: Financial Analysis11
No. Energy Conservation
Measures (ECM) Investment (BDT)
Financial savings (BDT)
Payback period (Years)
IRR (%)
NPV (BDT)
Project lifetime (Years)
1 Improve existing lighting systems by energy efficient lamps
428,000 282,857 1.8 59 221,778 5
2 Install AC energy saver in all ACs
1,200,000 1,190,379 1.2 153 2,073,870 5
3 Insulate the back side of boiler-2 (6 Ton/hr)
520,000 156,278 3.9 18 48,467 10
4 Insulate the back side of boiler-1
520,000 155,200 3.9 18 42,023 10
5 Insulate the back side of EGB 70,400 20,424 4.0 16 2,181 10
6 Replace clutch type sewing machines with servo type sewing machines
8,450,000 950,694 10.3 2 -5,471,551 17
7 Replace old stenter machine with new efficient stenter machine
40,000,000 4,830,134 9.6 7 -
18,869,667 20
8
Replace the old inefficient gas engine generator with new energy efficient gas engine generator
35,000,000 8,480,124 4.8 24 19,130,540 20
9 Recover heat from hot/warm cooling water generated
1,000,000 3,715,488 0.3 933 11,681,616 5
10 Recover heat from hot process baths (Effluent)
1,000,000 5,575,443 0.2 1469 18,479,056 5
11 Reduce excess air in boiler by fine tuning the burner
- 1,783,434 - - - 5
12 Preheat boiler feed water using the hot flue gases of the boiler through an economiser
1,500,000 1,486,195 1.2 153 2,585,837 5
13 Optimisation of compressed air system
1,000,000 1,358,137 0.9 257 3,066,383 5
14 Provide closed loop control for soft water pump
200,000 602,724 0.4 731 1,823,309 5
15 Provide VFD for cooling tower fan
250,000 180,817 1.6 77 186,544 5
16 Relocate 50% of the lamps in the garment section to other parts of the plant
- 1,071,508 - - - 5
17
Replacement of old IE1/IE2 class motors by energy efficient IE3 class motors in Karim Spinning Mills Ltd
2,420,000 5,104,620 0.6 472 14,064,489 5
18 Install VFD for humidification pumps in Karim Spinning Mills Ltd
679,000 699,020 1.1 164 1,266,528 5
19
Improve existing lighting systems by energy efficient lamps in Karim Spinning Mills Ltd
450,000 283,752 1.8 50 183,312 5
20 Reducing pressure of compressed air system and
300,000 1,866,458 0.2 1655 6,252,073 5
11 Real discount equity=15%, Interest on bank loan=13%
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operating one compressor with VFD in Karim Spinning Mills Ltd
21 Practice energy management 1,000,000 2,086,588 0.6 465 5,728,596 5
22
Install solar panel of 100 kW capacity for Purbani Fabrics Ltd, Purbani Yarn Dyeing Ltd and Karim Textiles Ltd
7,000,000 719,626 11.3 4 -4,354,969 20
23 Install solar panel of 100 kW capacity for Karim Spinning Mills Ltd.
7,000,000 689,675 11.7 3 -4,605,925 20
Table 7: Overall ECM summary against base year
Annual Energy Savings Potential Annual Cost Savings Potential
Potential CO2
Savings (MT)
Natural Gas in Cubic Meter
Electricity in kWh12
GJ BDT USD
Savings from ECM 3,277,170 2,121,568 133,430 43,289,575 541,120 8,435.45
Savings Percentage
27.9% 7.03% 29.6% 36.8% 33.1%
Table 8: Overall financial summary
Investment (BDT)
Financial Savings (BDT)
Payback period (Years)
IRR (%) NPV (BDT) Overall project lifetime
109,987,400 43,289,575 2.94 36% 71,387,914 10 Years
12 Total baseline electricity consumption of the factory= REB + Electricity generated by GEG + Electricity generated by DG = 30,199,351 kWh. (Provided by the factory)
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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1. Introduction
Purbani Composite Textiles Ltd. is one of the largest export oriented composite textile industries
in Bangladesh since 1973. The factory is located at Noorbag, Mouchak, Kaliakoir, Gazipur,
Dhaka. The composite factory is comprised of four sister concerns namely Purbani Fabrics Ltd.,
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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5. Energy Use Analysis and Benchmark Information on consumed energy and production can be used to calculate Specific Energy
Consumption (SEC) for production. SEC shows periodic (monthly, annual etc.) energy usage per
unit of production. It is an important tool for comparative analysis within an industry or sector.
SEC gives an idea of overall energy usage and intensity and helps in setting achievable bench
marks for a company based on existing equipment and processes. SEC values are calculated
based on monthly consumption of total energy source and production for different months of
201720. Figures-21-24 present these values.
5.0.1 Purbani Fabrics Ltd
Figure 21: Specific energy consumption of Purbani Fabrics Ltd. in 2017
For Purbani Fabrics Ltd., the maximum SEC of 28.59 GJ/Ton reached in February, 2017.
Minimum SEC of 16.63 GJ/Ton achieved in December, 2017 with a variation of 42% between
them.
5.0.2 Purbani Yarn Dyeing Ltd
Figure 22: Specific energy consumption of Purbani Yarn Dyeing Ltd. in 2017
20 Please see Annexure-1 for production and energy use data for 2017
0
5
10
15
20
25
30
35
SEC for Diesel SEC for NG SEC for Electricity (REB) SEC total
0
5
10
15
20
25
30
35
40
SEC for Diesel SEC for NG SEC for Electricity (REB) SEC total
GJ/T
on
G
J/T
on
mahfuz.rahman
Comment on Text
Why this is only for NG?
mahfuz.rahman
Comment on Text
Why this is only for NG?
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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For Purbani Yarn Dyeing Ltd, the maximum SEC of 37.64 GJ/Ton reached in August, 2017.
Minimum SEC of 17.90 GJ/Ton achieved in March, 2017 with a variation of 52% between them.
5.0.3 Karim Textiles Ltd
Figure 23: Specific energy consumption of Karim Textiles Ltd. in 2017
For Karim Textiles Ltd., the maximum SEC of 38.15 GJ/Thousand pcs reached in October, 2017.
Minimum SEC of 16.71 GJ/Thousand pcs achieved in December, 2017 with a variation of 56%
between them.
5.0.4 Karim Spinning Mills Ltd
Figure 24: Specific energy consumption of Karim Spinning Mills Ltd. in 2017
For Karim Spinning Mills Ltd, the maximum SEC of 46.81 GJ/Ton reached in November, 2017.
Minimum SEC of 32.38 GJ/Ton achieved in December, 2017 with a variation of 31% between
them.
0
5
10
15
20
25
30
35
40
45
SEC for Diesel SEC for NG SEC for Electricity (REB) SEC total
0
5
10
15
20
25
30
35
40
45
50
GJ/T
ho
usa
nd
Pcs
G
J/T
on
mahfuz.rahman
Comment on Text
Why this is only for NG?
mahfuz.rahman
Comment on Text
Fuel type is not clear here. Would be good to have same color legend like previous SEC scenarios.
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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Benchmarking the industries for energy efficiency is a challenging and debatable issue due to
wide variations in the working environment. The variation can be due to geography, climate,
manpower, working conditions etc. Generally, staff of companies opposes any global benchmark
on these grounds. Therefore, the benchmarks the consultants propose are the minimum SEC
achieved in December, 2017 for Purbani Fabrics Ltd; March, 2017 for Purbani Yarn Dyeing Ltd;
December, 2017 for Karim Textiles Ltd and Karim Spinning Mills Ltd for the study period which
in this case are 16.63 GJ/Ton, 17.90 GJ/Ton, 16.71 GJ/Thousand Pcs and 32.38 GJ/Ton
respectively21. This level of intensity cannot be disputed as the company has already achieved it
under the existing conditions. It is important for the management of the company to analyse the
activities and practices of that particular month where the minimum SEC was achieved and drive
the staff to replicate them going forward.
5.1 Month-wise production and energy use Month-wise production and energy use graphs show the usage pattern of the factory for the year
2017. After implementing the Energy Conservation Measures (ECMs), these graphs can be
compared with the graphs achieved after installation to identify energy savings or increase in
production.
5.1.1 Purbani Fabrics Ltd The graph below shows the month-wise production of Purbani Fabrics Ltd for 2017. Average
production for the year was 437 Ton. Maximum production of 530 Ton was achieved in
November, 2017 and minimum production of 287 Ton was achieved in September, 2017.
The graph below shows the month-wise diesel consumption of Purbani Fabrics Ltd. for 2017.
Average diesel consumption for the year was 1,077 liters. Maximum 1,308 liters of diesel was
consumed in March, 2017 and minimum 915 liters of diesel was consumed in February, 2017.
21 As the demand is variable for these products, it is up to the management to chalk out the minimum SEC possible depending on the market condition to maximize the product utilization.
0
100
200
300
400
500
600
Month-wise Production
Ton
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The graph below shows the month-wise natural gas consumption of Purbani Fabrics Ltd. for
2017. Average natural gas consumption for the year was 244,706 Cub. M. Maximum 282,790
Cub. M of natural gas was consumed in November, 2017 and minimum 191,266 Cub. M of natural
gas was consumed in September, 2017.
The graph below shows the month-wise electricity from REB consumption of Purbani Fabrics Ltd.
for 2017. Average electricity from REB consumption for the year was 17,772 kWh. Maximum
28,620 kWh of electricity was consumed in June, 2017 and minimum 3,604 kWh of electricity
was consumed in January, 2017.
0
200
400
600
800
1000
1200
1400
Month-wise Diesel Consumption
-
50,000
100,000
150,000
200,000
250,000
300,000
Month-wise Natural Gas Consumption
0
5000
10000
15000
20000
25000
30000
35000
Month-wise REB Consumption
Lite
r
Cu
b. M
kW
h
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5.1.2 Purbani Yarn Dyeing Ltd The graph below shows the month-wise production of Purbani Yarn Dyeing Ltd. for 2017.
Average production for the year was 206 Ton. Maximum production of 287 Ton was achieved in
March, 2017 and minimum production of 130 Ton was achieved in September, 2017.
The graph below shows the month-wise diesel consumption of Purbani Yarn Dyeing Ltd for 2017.
Average diesel consumption for the year was 908 liters. Maximum 1,046 liters of diesel was
consumed in July, 2017 and minimum 784 liters of diesel was consumed in March, April and
September, 2017.
The graph below shows the month-wise natural gas consumption of Purbani Yarn Dyeing Ltd. for
2017. Average natural gas consumption for the year was 149,244 Cub. M. Maximum 164,508
Cub. M of natural gas was consumed in January, 2017 and minimum 116,330 Cub. M of natural
gas was consumed in September, 2017.
0
50
100
150
200
250
300
350
Month-wise Production
0
200
400
600
800
1000
1200
Month-wise Diesel Consumption
-
50,000
100,000
150,000
200,000
Month-wise Natural Gas Consumption
Ton
L
ite
r
Cu
b. M
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The graph below shows the month-wise electricity from REB consumption of Purbani Yarn Dyeing
Ltd. for 2017. Average electricity from REB consumption for the year was 15,546 kWh. Maximum
25,042 kWh of electricity was consumed in June, 2017 and minimum 3,153 kWh of electricity
was consumed in January, 2017.
5.1.3 Karim Textiles Ltd The graph below shows the month-wise production of Karim Textiles Ltd. for 2017. Average
production for the year was 161 Thousand pieces. Maximum production of 240 Thousand pieces
was achieved in November, 2017 and minimum production of 110 Thousand pieces was
achieved in October, 2017.
The graph below shows the month-wise diesel consumption of Karim Textiles Ltd. for 2017.
Average diesel consumption for the year was 652 liters. Maximum 784 liters of diesel was
consumed in June, 2017 and minimum 523 liters of diesel was consumed in March and August,
2017.
0
5000
10000
15000
20000
25000
30000
Month-wise REB Consumption
050
100150200250300
Month-wise Production
0
200
400
600
800
1000
Month-wise Diesel Consumption
Kw
h
Th
ousand p
ieces
L
ite
r
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The graph below shows the month-wise natural gas consumption of Karim Textiles Ltd. for 2017.
Average natural gas consumption for the year was 106,603 Cub. M. Maximum 117,505 Cub. M
of natural gas was consumed in January, 2017 and minimum 83,093 Cub. M of natural gas was
consumed in September, 2017.
The graph below shows the month-wise electricity from REB consumption of Karim Textiles Ltd.
for 2017. Average electricity from REB consumption for the year was 11,108 kWh. Maximum
17,887 kWh of electricity was consumed in June, 2017 and minimum 2,252 kWh of electricity
was consumed in January, 2017.
5.1.4 Karim Spinning Mills Ltd The graph below shows the month-wise production of Karim Spinning Mills Ltd. for 2017. Average
production for the year was 445 Ton. Maximum production of 474 Ton was achieved in October,
2017 and minimum production of 388 Ton was achieved in September, 2017.
-
20,000
40,000
60,000
80,000
100,000
120,000
140,000
Month-wise Natural Gas Consumption
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
20000
Month-wise REB Consumption
0
100
200
300
400
500Month-wise Production
Cu
b. M
kW
h
Ton
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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The graph below shows the month-wise natural gas consumption of Karim Spinning Mills Ltd. for
2017. Average natural gas consumption for the year was 477,343 Cub. M. Maximum 558,016
Cub. M of natural gas was consumed in November, 2017 and minimum 387,500 Cub. M of natural
gas was consumed in December, 2017.
5.2 Energy consumption ratio Energy consumption ratio shows the ratio between electricity consumption from grid and thermal
energy consumption (natural gas, diesel etc.) of the factory.
5.2.1 Purbani Fabrics Ltd, Purbani Yarn Dyeing Ltd and Karim Textiles Ltd. The pie chart below shows the energy consumption ratio of Purbani Fabrics Ltd., Purbani Yarn
Dyeing Ltd and Karim Textiles Ltd. These factories consume a very small amount of electricity
from grid (1%) and rest of the consumption is thermal energy for power generation (84%) and
thermal energy for production process (15%).
-
100,000
200,000
300,000
400,000
500,000
600,000
Month-wise Natural gas Consumption
84%
15%
1%
Energy Consumption Ratio of Purbani Fabrics Ltd, Purbani Yarn Dyeing Ltd and Karim Textiles Ltd.
Thermal Energy used for power generation
Thermal Energy used for production process
Electrical Energy
Cu
b. M
mahfuz.rahman
Comment on Text
color legends are not clear enough
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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5.2.2 Karim Spinning Mills Ltd. The pie chart below shows the energy consumption ratio of Karim Spinning Mills Ltd. This factory
does not use any electricity from the grid. Therefore, the total consumption of the factory is
thermal energy for power generation.
100%
0
Energy Consumption Ratio of Karim Spinning Mills Ltd.
Thermal Energy Electrical Energy
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6. Energy Conservation Measures (ECMs) of Purbani Fabrics Ltd, Purbani Yarn Dyeing Ltd and Karim Textiles Ltd.
Based on an examination of the production process, auxiliary operations, and general practices
followed in the plant, the energy audit experts identified several Energy Conservation Measures
(ECMs). These are listed below:
ECM 1: Improve existing lighting systems by energy efficient lamps Current Practice The plant has around 535 numbers of conventional 40W T8 lights.
Proposed measure Replace the T-8 tube lights by 20 Watt LED lights. A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment 428,000 BDT
Annual Energy Saving 48,150 kWh of electricity
Annual Monetary Saving 282,857 BDT
Percentage of Savings 50%
Payback Period 1.8 Years
IRR 59%
NPV 221,778 BDT
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ECM 2: Install AC energy saver in all ACs Current Practice The plant has 80 air conditioners with total connected power around 790 kW and tons of refrigeration is 225 TR. 70 pcs of the ACs are split type with 750 kW and 10 pcs are window type with 40 kW motor rating. Proposed measure Install AC Energy Saver (AES) in all AC. It significantly reduces carbon emissions, improves air
quality and can save you up to 30% on your energy costs for air-conditioning. The standard
design of air conditioning is to operate continuously until the thermostat is satisfied, running the
compressor and producing a greater cooling capacity than the air can absorb. This of course
wastes energy. AES controls the thermostat and the compressor to achieve optimum balance
between efficiency and minimum energy consumption.
The AES principle of operation is to optimize the consumption of generated cooling thereby
leading to a reduction in the cooling generator’s utility consumption.
The AES contains a software “three dimensional model of cooling performance” that can be
continually and dynamically applied to any cooling unit during its operation. The AES will use its
connected sensor to compare the cooling unit’s actual performance against the software model
and determine when the best point of optimization is.
A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment 1,200,000 BDT
Annual Energy Saving 202,635 kWh of electricity
Annual Monetary Saving 1,190,379 BDT
Percentage of Savings 15%
Payback Period 1.2 Years
IRR 153%
NPV 2,073,870 BDT
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ECM 3: Insulate the back side of boiler-2 (6 Ton/hr) Current Practice The boiler is equipped with condensate heat recovery. However, the back side of boiler-2 is not
properly insulated. Therefore, a significant amount of energy is being wasted through heat
radiation.
Proposed measure Insulate the back surface of the boiler with proper insulating material (ceramic wool or ceramic
fibre).
A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment 520,000 BDT
Annual Energy Saving 20,139 Cub. M of natural gas
Annual Monetary Saving 156,278 BDT
Payback Period 3.9 Years
IRR 18%
NPV 48,467 BDT
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ECM 4: Insulate the back side of boiler-1 Current Practice The boiler is equipped with condensate heat recovery. However, the back side of boiler-1 is not
properly insulated. Therefore, a significant amount of energy is being wasted through heat
radiation.
Proposed measure Insulate the back surface of the boiler with proper insulating material (ceramic wool or ceramic
fibre).
A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment 520,000 BDT
Annual Energy Saving 20,000 Cub. M of natural gas
Annual Monetary Saving 155,200 BDT
Payback Period 3.9 Years
IRR 18 %
NPV 42,023 BDT
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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ECM 5: Insulate the back side of EGB Current Practice The back side of the Exhaust Gas Boiler (EGB) is not properly insulated. Therefore, a significant
amount of energy is being wasted through heat radiation.
Proposed measure Insulate the back surface of the boiler with proper insulating material (ceramic wool or ceramic
fibre).
A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment 70,400 BDT
Annual Energy Saving 2,632 Cub. M of natural gas
Annual Monetary Saving 20,424 BDT
Payback Period 4.0 Years
IRR 16%
NPV 2,181 BDT
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ECM 6: Replace clutch type sewing machines with servo type sewing machines Current Practice The plant has 338 clutch type sewing machines which consume around 269,724 kWh per year.
Production capacity of these types of sewing machines is very low and consumes more energy
compared to the servo type sewing machines.
Proposed measure Replace the clutch type sewing machines with new energy efficient servo type sewing machines.
These types of modern sewing machines use servo motor, which is operated only when the
operator needs to sew. These machines have very good starting torque and immediately provide
power to the machine's needle. A servo motor is a direct current (d.c.) machine - to run on an
alternating current (a.c.) they need an electronic pack to convert the power supply. Although this
increases the initial investment, the savings can have a significant positive impact on the factory's
energy cost.
A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment 8,450,000 BDT
Annual Energy Saving 161,834 kWh of electricity
Annual Monetary Saving 950,694 BDT22
Percentage of Savings 60%
Payback Period 10.3 Years
IRR 2%
NPV -5,471,551 BDT
22 Resale value of the clutch type sewing machines and increase in production for new sewing machines were not considered
mahfuz.rahman
Comment on Text
Would it be wise to go for this ECM with this weak financial indicators?
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
Page | 36
ECM 7: Replace the old stenter machine with new efficient stenter machine Current Practice The plant has an old stenter machine which consumes around 161 Cub. M/hr of natural gas and
production capacity is around 6 tons/day. The plant already has another stenter machine which
is new and efficient compared to the old one.
Proposed measure Replace the old stenter machine with the new one which will consume around 70 Cub. M/hr of
natural gas and production capacity is around 9.5 tons/day.
A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment 40,000,000 BDT
Annual Energy Saving 622,440 Cub. M of natural gas
Annual Monetary Saving 4,830,134 BDT 23
Percentage of Savings 56%
Payback Period 9.6 Years
IRR 7%
NPV -18,869,667 BDT
23 Resale value of the old stenter machine and increase in production for new machine were not considered
mahfuz.rahman
Comment on Text
Would it be wise to go for this ECM with this weak financial indicators?
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
Page | 37
ECM 8: Replace the old inefficient gas engine generator with new energy efficient gas engine generator
Current Practice There are two 900 kW GEGs and one 750 GEG for meeting the electrical energy requirements
of the plant. One of the 900 kW GEG i.e. GEG No.2 has completed 1,18,000 hours of operation.
The energy performance of the engine has deteriorated and currently produces 2.3 kWh/Cub. m
of natural gas.
Proposed measure It is suggested to replace this No.2 GEG with a new energy efficient GEG of 900 kW which will
produce 3.22 kWh/Cub. M of natural gas.
A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment 35,000,000 BDT
Annual Energy Saving 531,429 Cub. M of natural gas
Annual Monetary Saving 8,480,124 BDT
Percentage of Savings 40%
Payback Period 4.8 Years
IRR 24%
NPV 19,130,540 BDT
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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ECM 9: Recover heat from hot/warm cooling water generated Current Practice The dyeing process involves several steps of heating and cooling. The hot processes need to be
cooled subsequently by circulation of cooling water. This water which attains a temperature of
50oC is collected in a separate underground sump. The steam condensate from the process is
also collected in the same sump.
Proposed measure Since the condensate is high in purity and available at a higher temperature (80oC), it is
suggested to segregate steam condensate and cooling water by providing a partition in the sump.
A separate pump may be installed to pump the condensate to the boiler feed water tank. The
cooling water at 50oC may be circulated through a ring main system in the dye house with a VFD
driven pump. The pressure may be set at 1.5 kg/cm2. This water can be used to fill the dyeing
machines whenever hot wash is to be used in the machines. Since the water enters at a higher
temperature of 50oC considerable amount of steam can be saved. In addition, cycle time for the
process can be reduced leading to higher production and improved productivity.
A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment 1,000,000 BDT
Annual Energy Saving 478,800 Cub. M of natural gas
Annual Monetary Saving 3,715,488 BDT
Payback Period 0.3 Years
IRR 933%
NPV 11,681,616 BDT
mahfuz.rahman
Comment on Text
?
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
Page | 39
ECM 10: Recover heat from hot process baths (Effluent) Current Practice The hot process/dye baths are discarded to the ETP in hot condition. This not only wastes the
energy in the hot baths but also causes nuisance to the proper operation of ETP. An enormous
amount of energy is also spent in operating the twin lobe air blowers in ETP for cooling purpose.
The following high temperature baths are released to the ETP:
Process Temperature
Scouring 80oC
BD hot wash 80oC
Enzyme 70oC
Dyeing 1 70oC
Dyeing 2 70oC
Proposed measure The hot dye effluents are to be collected separately in an underground tank. This should be
preceded by segregation of hot and cold effluents in separate pipes by automatic valve control
programmed with machine PLC. If it is hot wash, then valve opens to hot tank. If cold wash, then
it is directed to ETP. This will ensure maximum heat recovery from the effluents. After cooling
down of the effluents the process baths may be sent to ETP. This will ensure minimum operating
temperature in ETP leading to better operation of ETP and reduction of electrical energy
consumption for blowers in ETP.
A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment 1,000,000 BDT
Annual Energy Saving 718,485 Cub. M of natural gas
Annual Monetary Saving 5,575,443 BDT
Payback Period 0.2 Years
IRR 1469%
NPV 18,479,056 BDT
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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ECM 11: Reduce excess air in boiler by fine tuning the burner Current Practice There are three 6 T/h natural gas fired boilers apart from one 3 T/h exhaust gas boiler. The steam
generation pressure is 6 kg/cm2. Normally two boilers are in operation. Flue gas analysis was
performed in all the three gas fired boilers. The results are shown in the following table.
Boiler Flue gas temperature, oC Oxygen % Excess air %
1 164 11.3 117
2 191 12.6 152
3 196 4.9 30
Proposed measure Boiler 3 is being operated efficiently as the excess air is around the desirable level of 30%. In the
other two boilers the excess air level is very high and the burners require tuning.
A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment Nil
Annual Energy Saving 229,824 Cub. M of natural gas
Annual Monetary Saving 1,783,434 BDT
Payback Period Immediate
IRR -
NPV -
Boiler-1 Boiler-2 Boiler-3
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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ECM 12: Preheat boiler feed water using the hot flue gases of the boiler through an economiser Current Practice The average exhaust temperatures in the three boilers is about 180oC. Inlet temperature of boiler
feed water is 70 oC. The flue gas from the boiler is currently disposed off to the environment and
hereby being unutilized.
Proposed measure An economiser may be provided to preheat the boiler feed water which will attain 90oC at the
outlet. This can be fed to the boiler. The temperature gain by the feed water is 20oC. This measure
is about to be implemented by the factory.
A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment 1,500,000 BDT
Annual Energy Saving 191,520 Cub. M of natural gas
Annual Monetary Saving 1,486,195 BDT
Payback Period 1.2 Years
IRR 153%
NPV 2,585,837 BDT
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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ECM 13: Optimisation of compressed air system Current Practice The plant has seven air compressors to meet its pneumatic requirement. They are:
Machine no. Brand Motor Rating (kW)
1 Boge 75 kW
2 Ally-win 75 kW
3 Boge 45 kW
4 Boge 30 kW
5 Boge 30 kW
6 Kaiser 30 kW
7 Atlascopco 37 kW
All the compressors are in operation barring one 30 kW compressor. The pressure maintained
is between 5-6 kg/cm2.
Proposed measure
The knitting unit requires a pressure of only 3 kg/cm2. Hence one 75 kW compressor can be
moved near the knitting section and provided with a VFD. The system pressure for knitting unit
may be maintained between 3-3.2 kg/cm2.
For the remaining requirement, 1x 45, 1 x 37, 2 x 30 kW may be operated at full load and is not
likely to unload. This will meet the base load air requirement. The other 75 kW may be provided
with VFD for meeting the fluctuating variable requirement. This will avoid the unnecessary
unloading power consumption.
A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment 1,000,000 BDT
Annual Energy Saving 231,192 kWh of electricity
Annual Monetary Saving 1,358,137 BDT
Percentage of Savings 45%
Payback Period 0.9 Years
IRR 257 %
NPV 3,066,383 BDT
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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ECM 14: Provide closed loop control for soft water pump Current Practice The soft water for process is supplied through a ring main system by 30 kW pump with VFD.
However, the VFD is in manual mode.
Proposed measure It is suggested to provide a constant pressure controller and provide a feedback to VFD to
maintain the pressure while varying the flow. The pressure may be maintained at 2 kg/cm2.
A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment 200,000 BDT
Annual Energy Saving 102,600 kWh of electricity
Annual Monetary Saving 602,724 BDT
Percentage of Savings 50%
Payback Period 0.4 Years
IRR 731%
NPV 1,823,309 BDT
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
Page | 44
ECM 15: Provide VFD for cooling tower fan Current Practice The gas generators are water cooled with cooling towers. The cooling tower fan is of 7.5 kW and
is continuously in operation round the clock. When the cold water temperature reaches close to
wet bulb there is no use operating the fan.
Proposed measure It is suggested to provide VFD for all the three fans and control may be set for a fixed cold water
temperature.
A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment 250,000 BDT
Annual Energy Saving 30,780 kWh of electricity
Annual Monetary Saving 180,817 BDT
Percentage of Savings 20%
Payback Period 1.6 Years
IRR 77%
NPV 186,544 BDT
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
Page | 45
ECM 16: Relocate 50% of the lamps in the garment section to other parts of the plant Current Practice The garment section appears to over illuminated. There are 4000 LED lamps of 20 W. This alone
contributes to a load of 80 kW.
Proposed measure It is suggested to remove one lamp from each fitting and relocate to other areas which contains
40 W tubes. There are about 2000 tubes of 40 W.
A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment Nil
Annual Energy Saving 182,400 kWh of electricity
Annual Monetary Saving 1,071,508 BDT
Percentage of Savings 50%
Payback Period -
IRR -
NPV -
mahfuz.rahman
Comment on Text
Please mention the measured illumination data and justification of replacing 50% of the installed lamps. Also mention what will be the illumination once the ECM takes place.
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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6.1 Energy Conservation Measures (ECMs) of Karim Spinning Mills Ltd. Based on an examination of the production process, auxiliary operations, and general practices
followed in the plant, the energy audit experts identified several Energy Conservation Measures
(ECMs). These are listed below:
ECM 17: Replacement of old IE1/IE2 class motors by energy efficient IE3 class motors Current Practice The plant has around 500 nos of old IE1/IE2 class motors with a total rating of 1100 kW. The
average efficiency of the motors is around 79%.
Proposed measure Replace the IE1/IE2 class motors with IE3 class motors which will increase the efficiency to 86%. A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment 2,420,000 BDT
Annual Energy Saving 906,682 kWh of electricity
Annual Monetary Saving 5,104,620 BDT
Percentage of Savings 9%
Payback Period 0.6 Years
IRR 472%
NPV 14,064,489 BDT
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
Page | 47
ECM 18: Install VFD for humidification pumps Current Practice The three humidification plants currently have pumps of 30 kW, 22 kW and 45 kW capacity. These
humidification pumps do not have variable frequency drive installed.
Proposed measure Water injection should be based on humidity. It is suggested to install a humidity sensor with a
feedback to VFD for the pumps.
A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment 679,000 BDT
Annual Energy Saving 124,160 kWh of electricity
Annual Monetary Saving 699,020 BDT
Percentage of Savings 20%
Payback Period 1.1 Years
IRR 164%
NPV 1,266,528 BDT
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
Page | 48
ECM 19: Improve existing lighting systems by energy efficient lamps Current Practice There are around 1600 fittings of lights. Most of the tubes have already been replaced with 22 W
LED. 450 nos of lights are 36 W T5 lights.
Proposed measure It is suggested to replace rest of the 450 lights also with LED. In addition, optimisation of Lamps
with respect to need is suggested. De-lamp (remove) one lamp from twin tube wherever lighting
is sufficient. These removed lamps can be utilized for partly replacing remaining 450 lamps to
LED.
A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment 450,000 BDT
Annual Energy Saving 50,400 kWh of electricity
Annual Monetary Saving 283,752 BDT
Percentage of Savings 38%
Payback Period 1.8 Years
IRR 50%
NPV 183,312 BDT
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
Page | 49
ECM 20: Reducing pressure of compressed air system and operating one compressor with VFD Current Practice The plant currently has 4 compressors of rating 37 kW each. Existing pressure setting is set to
7.6 to 8.5 kg/cm2.
Proposed measure It is suggested to operate three compressors with an unload setting of 7 kg/cm2. The forth
compressor is to be connected to VFD and operated between 6.8 to 6.9 kg/cm2 with pressure
feedback to VFD.
A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment 300,000 BDT
Annual Energy Saving 331,520 kWh of electricity
Annual Monetary Saving 1,866,458 BDT
Percentage of Savings 28%
Payback Period 0.2 Years
IRR 1655%
NPV 6,252,073 BDT
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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ECM 21: Practice energy management Current Practice There are several areas the plant is currently losing energy inadvertently such as improper
combustion, electrical appliances management according to occupancy, leakage in steam
pipeline, use of day light, measurement and monitoring etc. These housekeeping options are not
being properly maintained.
Proposed measure An energy management team should be created and this team should include an internal energy
auditor, factory manager, production manager and utility manager as members. This team would
develop energy programs, communicate to all staff regarding energy efficiency and provide
monthly updates on the implementation and results. The team should also set an annual target
for energy saving. Generally, if there are staffs allocated for such tasks they will continuously find
areas for improvement. The team should be trained so that they are equipped with adequate
skills. Some areas for coverage for the team could be:
Ensure optimized combustion. This can be done by analyzing the flue gas of the generator
and controlling the air-fuel ratio.
Repair the leakage if there is any to prevent losses of gas, steam and air.
Ensuring proper maintenance of motors, compressors, generators, boilers etc.
Monitoring the use of lights and fans according to occupancy.
Use of daylight as much as possible.
Measuring energy consumption parameters of each machine and monitoring. A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment 1,000,000 BDT
Annual Energy Saving 216,901 Cub. M of natural gas
Annual Monetary Saving 2,086,588 BDT
Percentage of Savings 2%
Payback Period 0.6 Years
IRR 465%
NPV 5,728,596 BDT
mahfuz.rahman
Comment on Text
Is this an assumption on energy savings earned by energy management? if so, please explain properly to make it easier to the reader to understand.
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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7. Renewable Energy Options In addition to the energy conservation measures presented above, there are some renewable
energy options which can provide a significant amount of energy savings:
ECM 22: Install solar panel of 100 kW capacity for Purbani Fabrics Ltd, Purbani Yarn
Dyeing Ltd and Karim Textiles Ltd
Current Practice The plant uses electricity from GEG, DG and it has grid connection from REB. The generation
cost of electricity from GEG is BDT 5.63 per kWh and rate of REB is BDT 8.15 per kWh.
Proposed measure It is proposed to install 100 kW solar PV plant. The solar panel will utilize the solar power falling
upon a large area of the roof of the factory.
A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment 7,000,000 BDT
Annual Energy Saving 122,500 kWh of electricity
Annual Monetary Saving 719,626 BDT
Payback Period 11.3 Years
IRR 4%
NPV -4,354,969 BDT
mahfuz.rahman
Comment on Text
Is the roof-top has enough space considering the shading and structural strength for 100kWp solar project? Also please justify the capacity i.e. 100kWp? Please insert a picture of the roof-top.
mahfuz.rahman
Comment on Text
Indicators seem weaker than expected.
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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ECM 23: Install solar panel of 100 kW capacity for Karim Spinning Mills Ltd. Current Practice The plant uses electricity from GEG. The generation cost of electricity from GEG is BDT 5.63 per
kWh.
Proposed measure It is proposed to install 100 kW solar PV plant. The solar panel will utilize the solar power falling
upon a large area of the roof of the factory.
A snapshot of the Cost and Benefit Analysis is provided in the table below. For detailed
calculations, please refer to Annexure-8.
Investment 7,000,000 BDT
Annual Energy Saving 122,500 kWh of electricity
Annual Monetary Saving 689,675 BDT
Payback Period 11.7 Years
IRR 3%
NPV -4,605,925 BDT
Carbon Dioxide (CO2) Emission Reduction Adoption of the above mentioned ECMs are estimated to reduce CO2 emission by 8,435 MT per year.
mahfuz.rahman
Comment on Text
Is the roof-top has enough space considering the shading and structural strength for 100kWp solar project? Also please justify the capacity i.e. 100kWp? Please insert a picture of the roof-top.
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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8. Additional Energy Conservation Measures ECM: Recovery of heat from engine jacket water Current Practice The plant is currently using Gas Engine Generators of capacity 2x900 kW and 1x750 kW. The
average load of the plant is about 1800 kW.
Proposed measure The heat available in the engine jacket water is equivalent to power generated. The primary
cooling circuit operates between 70oC (inlet) to 80oC (outlet). This heat from the primary circuit is
taken away by secondary cooling water circulation which in turn rejects the absorbed heat in the
cooling tower and then to the atmosphere. Instead of wasting the heat it is suggested to produce
hot water at 70oC which can be used in the process. The calculation projects the potential but
the utilisation depends on the need.
A snapshot of the cost, benefit analysis and detailed calculations are provided below:
Investment 5,000,000 BDT
Annual Energy Saving 1,484,280 Cub. M of natural gas
Annual Monetary Saving 11,518,012 BDT
Payback Period 0.5 Years
IRR 527%
NPV 32,608,519 BDT
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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ECM Calculation: Recovery of heat from engine jacket water
Average load on the engines 1800 kW
Heat rejected to the jacket 1800 kW
1800 x 860 =1,548,000
kcal/hr
Quantity of hot water that can be produced with 30oC inlet and 70oC outlet
1,548,000/ (70-30) x 1000 =38.7
Cub. M /hr
38.7 x 24
=929 Cub. M /day
Gas saving in steam boiler consumption 1,548,000/ (0.85 x 8400)
=217 Cub. M /hr
Annual gas saving potential @6840 hours per year operation
217 x 6840 =1,484,280
Cub. M /year
Annual monetary savings potential @BDT 7.76 per Cub. M
1,484,280 x 7.76 =11,518,012
BDT
Investment 5,000,000 BDT
Project lifetime 5 Years
Payback period 0.5 Year
IRR 527 %
NPV 32,608,519 BDT
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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9. Operational Practices This section outlines the operational practices adopted by different companies that have been
successful in composite textile industries. Purbani Composite Textiles Ltd may like to consider
their adoption for improving efficiency and quality. We have not taken them into the analysis as
we consider them to be housekeeping measures.
Improving and maintaining proper power factor
Normally industrial loads possess a low power factor which is a drawback for a power system.
The power supply companies impose penalty for low power factor (PF). At the same time this is
harmful for the companies also due high current flowing in the equipment’s and high distribution
losses. The consultants have suggested maintaining proper power factor using a power factor
unit of proper size.
Energy efficient motors
Existing motors are conventional and consume excess energy. Consultants suggest replacing
those motors with latest energy efficient motors gradually. The big motors should be given the
priority.
Cooling tower maintenance
It has been observed that cleaning and maintenance of cooling towers is less frequent than
required. Regular maintenance will obviously improve the performance of the towers and will
reduce the lot on compressors.
Instrumentation Instrumentation in the boilers and other equipment is inadequate. A few vital instruments in these
areas will certainly improve scope for better monitoring and control of process parameters. An
amount of BDT 0.5 million may be spent for the instrumentation.
Energy Assessment It is recommended by the consultants to perform energy assessment in the factory every two or
three years. This practice will enable the factory management to identify new energy savings
options and will help to measure achieved savings for previous energy efficient investments. In
addition, regular energy assessment will provide an energy benchmark of factory’s own
perspective which will assist to analyze the production performance of the factory.
Preventive Maintenance Preventive maintenance is maintenance that is regularly performed on a piece of equipment to
lessen the likelihood of it failing. Preventive maintenance is performed while the equipment is still
working, so that it does not break down unexpectedly. It is advised by the consultants to practice
preventive maintenance and plan it accordingly so that any required resources are available
beforehand.
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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10. Organizational Analysis An analysis of the current state of energy management at the company was done using the
Energy Management Matrix developed by the UK Oxfordshire based Carbon Trust’s Energy
Efficiency – Best Practice Programme (EEBPP) – Good Practice Guide 119: Organizing Energy
Management – A Corporate Approach. The matrix presented in the next page is used to rate an
organization in six different areas of management, namely: policy, organization, communication,
information, marketing and investment. A summary of the company’s rating is as follows:
Area of Management Matrix Reading
Policy 1
Organization 0
Communication 1
Information 1
Marketing 1
Investment 2
As indicated in the Energy Management Matrix, there are five rating levels, from 0, which means
that an organization has no provisions for energy management, to 4, which represents industry
best practice. The current status of the company against these parameters has been highlighted
in the table. The cells in the matrix of the next page identify the steps to be taken by the company
to improve its rating.
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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11. Energy Management Matrix
Rank
Policy Organization Communication Information Marketing Investment
4
Energy policy, action plan and regular review have commitment of top management as part of an environmental strategy.
Energy management fully integrated into management structure. Clear delegation of responsibility for energy consumption.
Formal and informal channels of communication regularly exploited by energy manager and energy staff at all levels.
Comprehensive system sets targets, monitors consumption, identifies faults, quantifies savings and provides budget tracking.
Marketing the value of energy efficiency and the performance of energy management both within the organization and outside it.
Positive discrimination in favour of ‘green’ schemes with detailed investment appraisal of a new-build and refurbishment opportunities.
3
Formal energy policy but no active commitment from top management
Energy manager accountable to energy committee representing all users, chaired by a member of the managing board.
Energy committee used as main channel together with direct contact with major users
M&T reports for individual premises based on sub-metering. But savings not reported effectively to users
Programme of staff awareness and regular publicity campaigns
Same pay back criteria employed as all other investment
2
Unadopted energy policy set by energy manager or senior departmental manager.
Energy manager in post, reporting to ad-hoc committee but line management and authority are unclear
Contact with major users through ad-hoc committee chaired by senior departmental manager.
Monitoring and targeting reports based on supply meter data. Energy unit has ad-hoc involvement in budget setting
Some ad-hoc staff awareness training
Investment using short term pay back criteria only
1
An unwritten set of guidelines
Energy management the part time responsibility of someone with only limited authority or influence
Informal contacts between engineer and a few users
Cost reporting based on invoice data. Engineer compiles reports for internal use with technical department
Informal contacts used to promote energy efficiency
Only low cost measures taken
0
No explicit policy No energy management or any formal delegation of responsibility for energy consumption
No contact with users
No information system. No accounting for energy consumption
No promotion of energy efficiency
No investment in increasing energy efficiency in premises
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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12. Conclusion Purbani Composite Textiles Ltd. has some guideline regarding energy policy however there is no
energy manager responsible for reporting to the top management regarding energy efficiency.
But all technical staffs are aware of energy efficiency improvements in their facility. There are
informal contacts between engineer and a few users. There is monitoring and targeting reports
based on supply meter data. Regular staff awareness training is required for better improvement
in energy efficiency.
An Investment grade energy audit identifies a number of scopes for implementation to ensure
better energy efficient operation. This report gives specific energy saving calculations and their
financial viability. The management is enthusiastic in implementing such measures towards
conserving energy.
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd.
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13. Recommendations The consultants suggested to:
a) improve existing lighting systems by energy efficient lamps
b) install AC energy saver in all ACs
c) insulate the back side of boiler-2 (6 Ton/hr)
d) insulate the back side boiler-1
e) insulate the back side of EGB
f) replace clutch type sewing machines with servo type sewing machines
g) replace old stenter machine with new efficient stenter machine
h) replace the old inefficient gas engine generator with new energy efficient gas engine
generator
i) recover heat from hot/warm cooling water generated
j) recover heat from hot process baths (Effluent)
k) reduce excess air in boiler by fine tuning the burner
l) preheat boiler feed water using the hot flue gases of the boiler through an economiser
m) optimisation of compressed air system
n) provide closed loop control for soft water pump
o) provide VFD for cooling tower fan
p) relocate 50% of the lamps in the garment section to other parts of the plant
q) replacement of old IE1/IE2 class motors by energy efficient IE3 class motors in Karim
Spinning Mills Ltd
r) install VFD for humidification pumps in Karim Spinning Mills Ltd
s) improve existing lighting systems by energy efficient lamps in Karim Spinning Mills Ltd
t) reducing pressure of compressed air system and operating one compressor with VFD in
Karim Spinning Mills Ltd
u) practice energy management
v) install solar panel of 100 kW capacity for Purbani Fabrics Ltd, Purbani Yarn Dyeing Ltd
and Karim Textiles Ltd
w) install solar panel of 100 kW capacity for Karim Spinning Mills Ltd.
The consultants suggested to install solar panel, energy efficient machineries, inverters in motors,
VFD in compressors, LED lights in future expansion program. Sub-metering should be installed
in all the machineries for monitoring and measuring the energy efficiency of the individual
equipment. An energy management team should be created to develop energy programs,
communicate to all staff regarding energy efficiency and set an annual target for energy saving.
All the suggested recommendations put together presents a very attractive measures towards
conserving energy. The proposals are financially attractive as overall IRR, NPV and payback
period are 36%, BDT 71,387,914 and 2.94 years respectively.
mahfuz.rahman
Comment on Text
It was requested to comment on the space constraints and its impact on the proposed ECMs. Please include the same. Also please provide an analysis on the most attractive ECMs based on the financial indicators. Recommendation like no. f) does not seem to be that interesting. Presentation of a clear picture in very important.
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd
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ANNEXURE 1: ENERGY USE IN 2017
Total energy consumption
Month
Diesel Consumption NG Consumption Electricity Consumption
Measure Parameters: O2 0-21% CO 0-4,000ppm (hydrogen compensated) Differential pressure Temperature - inlet / flue gas / differential CO 0-100,000ppm NO 0-100ppm NO 0-5,000ppm O2 0-1,000ppm SO2 0-100ppm SO2 0-5,000ppm Excess air Combustion efficiency
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd
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ANNEXURE 6: RULE OF THUMB (ROT) USED IN ANALYSIS
1. 1% gas can be saved for every 200 C rise of air temperature.
2. 1 Kg of natural gas requires 17 kg of air for combustion. If we include 5% of excess air it
should be 17.85 Kg air for burning properly 1 kg of natural gas.
3. The conversion efficiency of heat exchanges (Economizer, air pre-heaters, recuperator
etc. is 60-65%)
4. Replacement of T8 light by T5 lights saves Energy by 25%.
5. Heat rate of waste heat recovery power plant is 4,000 Kcal/kWh
6. The cost of waste heat recovery power plant is 100 million BDT/MW
7. Pl. add one BDT/kWh towards capital cost, financing charge, O & M etc while calculating
cost of kWh generation from gas generators
8. In a compressor reduction of one discharge pressure by one kg/cm2 normally saves
power by 9-10 %.
9. 1 Ton AC requires 3,000 Kcal /hr.
10. Increase in feed water temp by 60C reduces fuel consumption by 1%.
11. 10% reduction in excess air improves Boiler efficiency by 1%.
12. Waste Heat Boiler (WHB) produces 500 kg steam per 1,000 kW heat input.
13. Insulation cost is BDT 8,000 per square meter for HVAC system.
14. Cost of high efficiency motor with inverter is BDT 2,200 per kW power rating.
15. Cost of VFD/Inverter is BDT 7,000 per kW power rating.
16. Energy management can save up to 2% of the overall energy consumed by the plant.
17. Every 1°C increase in the set temperature of air conditioner reduces the power
consumption by 3%
18. Every one percent reduction in oxygen in flue gas will reduce gas consumption by 1%
19. Every 1 bar reduction in compressed air pressure reduces the power consumption by
8%
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ANNEXURE 7: ASSUMPTIONS OF FINANCIAL ANALYSIS
Assumptions Value
Base year 2017
Currency unit used in the analysis BDT
Capital-linked payments Unit
Total equipment cost BDT
Cost of Engineering and Civil work BDT 10% of capital cost
EPC (engineering, procurement, construction) cost
BDT
Import duty and taxes BDT 10% of capital cost
Construction time insurance BDT 2% of the cost of Engg--
Contingencies BDT 5% of EPC
Operation-linked payments Unit
O&M costs (in first year) BDT 5% of Capital Cost
Insurance cost BDT 1% of capital cost
Economic variables Unit
Real Discount rate Equity % 15%
Sources of funds Unit
Loan Financing % 70%
Equity Capital % 30%
Loan repayment term Year 5 years
Interest on Bank Loan % 13%
Real annual escalation rate (Growth rate) Unit
Fuel cost (Gas and HSD) % 5%
Electricity cost % 5%
Other consumption-linked costs % 5%
O&M cost % 5%
Salary and Adm. Costs % 10%
Insurance cost % 5%
Other operational costs % 5%
Tax Payment Unit
Tax (1st - 5th year) % 30%
Tax (6th - 10th year) % 30%
Tax (11th - 15th year) % 30%
Tax (16th year onwards) % 30%
Any other tax % 0%
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ANNEXURE 8: CALCULATIONS OF ECMs
ECM 1: Improve existing lighting systems by energy efficient lamps
Total number of 40W T8 Tube Lights 535
Annual energy savings by replacing with Energy efficient lights
{No.of lights x (Previous Wattage-Energy efficient light wattage) x Annual
Running Hours}/1000 = {535 x (40-20) x 4500}/1000
=48,150
kWh
Annual monetary saving @BDT 5.63 per kWh for GEG, BDT 8.15 per kWh for REB and BDT 20 per kWh for DG24
48,150 x (5.63 x 0.95 + 8.15 x 0.04 + 20 x 0.01)
=282,857
BDT
Total Investment @BDT 800 per light 428,000 BDT
Project lifetime 5 Years
Payback period 1.8 Years
IRR 59 %
NPV 221,778 BDT
ECM 2: Install AC energy saver in all ACs
Connected power of the AC 790 kW
Annual Electricity consumption Power x Running Hour =790 x 1710 =1,350,900
kWh
Annual Electricity savings after installing AC energy saver 15% at conservative scale
202,635 kWh
Annual monetary saving @BDT 5.63 per kWh for GEG, BDT 8.15 per kWh for REB and BDT 20 per kWh for DG12
202,635 x (5.63 x 0.95 + 8.15 x 0.04 + 20 x 0.01)
=1,190,379
BDT
Investment @BDT 15,000 per AC 1,200,000 BDT
Project lifetime 5 Years
Payback period 1.2 Years
IRR 153 %
NPV 2,073,870 BDT
24 The plant uses GEG, REB and DG for power generation. 95% power is generated using GEG, 4% using REB and 1% using DG.
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ECM 3: Insulate the back side of boiler-2 (6 Ton/hr)
Ambient temperature 30 Deg C
Surface temperature at present 124 Deg C
Surface temperature after installing proposed insulation
80 Deg C
Area 65 sq. meter
Operating hours 6,840 hour
Annual reduction in heat lost through surface25 24 kW
Natural gas calorific value 38.109x1,000 kJ/cubic meter
Boiler efficiency 77 %
Annual NG savings (24x6840x3,600)/
(0.77 x38.109x1,000) = 20,139
cubic meter
Annual monetary saving @BDT 7.76 per Cub. M 156,278 BDT
Investment @ BDT 8,000 per square meter 520,000 BDT
Project lifetime 10 Years
Payback period 3.9 Years
IRR 18 %
NPV 48,467 BDT
ECM 4: Insulate the back side of boiler-1
Ambient temperature 30 Deg C
Surface temperature at present 127 Deg C
Surface temperature after installing proposed insulation 80 Deg C
Area 65 sq. meter
Operating hours 6,840 hour
Annual reduction in heat lost through surface26 26 kW
Natural gas calorific value 38.109x1,000 kJ/cubic meter
Boiler efficiency 80 %
Annual NG savings (26x6840x3,600)/
(0.80 x38.109x1,000) = 20,000
cubic meter
Annual monetary saving @BDT 7.76 per Cub. M 155,200 BDT
Investment @ BDT 8,000 per square meter 520,000 BDT
Project lifetime 10 Years
Payback period 3.9 Years
IRR 18 %
NPV 42,023 BDT
25Using standard radiation formula 26Using standard radiation formula
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ECM 5: Insulate the back side of EGB
Ambient temperature 30 Deg C
Surface temperature at present 124 Deg C
Surface temperature after installing proposed insulation 80 Deg C
Area 8.8 sq. meter
Operating hours 6,840 hour
Annual reduction in heat lost through surface27 3.3 kW
Natural gas calorific value 38.109x1,000 kJ/cubic meter
Annual NG savings (3.3x6840x3,600)/
(0.81 x38.109x1,000) = 2,632
cubic meter
Annual monetary saving @BDT 7.76 per Cub. M 20,424 BDT
Investment @ BDT 8,000 per square meter 70,400 BDT
Project lifetime 10 Years
Payback period 4.0 Years
IRR 16 %
NPV 2,181 BDT
ECM 6: Replace clutch type sewing machines with servo type sewing machines
Annual power consumption 338x350x2,280/1000 =269,724
kWh
Annual savings 60% for servo motors 269,724x0.6 =161,834
kWh
Annual monetary saving @BDT 5.63 per kWh for GEG, BDT 8.15 per kWh for REB and BDT 20 per kWh for DG12
161,834 x (5.63 x 0.95 + 8.15 x 0.04 + 20 x 0.01)
=950,694
BDT
Investment @BDT 25,000 per machine 8,450,000 BDT
Project lifetime 17 Years
Payback period 10.3 Years
IRR 2 %
NPV -5,471,551 BDT
27Using standard radiation formula
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ECM 7: Replace old stenter machine with new efficient stenter machine
Old machine NG consumption 161 Cub. M/hr
New machine NG consumption 70 Cub. M/hr
Running hour/yr 6,840 hr
Annual NG savings for the same amount of kWh generation for the proposed heat rate
(161-70) x 6840 =622,440
Cub. M
Annual monetary saving @BDT 7.76 per Cub. M 4,830,134 BDT
Investment 40,000,000 BDT
Project lifetime 20 Years
Payback period 9.6 Years
IRR 7 %
NPV -18,869,667 BDT
ECM 8: Replace the old inefficient gas engine generator with new energy efficient gas engine generator
No of units generated by 900 kW GEG (No.2) in the previous year (SBI)
4,278,000 kWh
No of units per Cub. M of gas (SBI) 2.3 kWh/Cub. M
Gas consumption for GEG No. 2 per year 4,278,000/2.3
=1,860,000 Cub. M
Projected no of units per Cub. M of gas for new energy efficient gas engine (SBI)
3.22 kWh/Cub. M
Expected gas consumption with new energy efficient gas engine
4,278,000/3.22 =1,328,571
Cub. M
Annual savings in gas consumption 1,860,000-1,328,571
=531,429 Cub. M
Annual monetary saving @BDT 9.62 per Cub. M 531,429 x 9.62
=5,112,346 BDT
Total REB energy utilised per year(SBI) 533,105 kWh
Minimum energy allowable 267,120 kWh
Excess REB energy utilised 265,985 kWh
Cost of excess energy used @BDT 8.15/kWh 265,985 x 8.15
=2,167,778 BDT
Excess Lube oil consumption per year (SBI) 1,200,000 BDT
Total Monetary savings 5,112,346 + 2,167,778 +
1,200,000 =8,480,124
BDT
Investment for new GEG 35,000,000 BDT
Project lifetime 20 Years
Payback period 4.8 Years
IRR 24 %
NPV 19,130,540 BDT
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ECM 9: Recover heat from hot/warm cooling water generated
Production per day 20,000 kgs
Liquor ratio 1:6
No of process steps 14
Total Water requirement per day for dyeing 20,000 x 6 x 14/1000
=1,680
Cub. M /day
No of steps with hot wash 5
Hot water requirement per day for dyeing 20,000 x 6 x 5/1000
=600 Cub. M /day
Heat rejected by hot effluent to cooling water 600,000 x 1 x (80-30)
=30,000,000 kcal/day
Temperature rise in cooling water (50-30)
=20 oC
Amount of cooling water at 50oC per day 30,000,000/ (20 x 1000)
=1500 Cub. M /day
Requirement of warm water for process 600 Cub. M /day
Energy saving by supplying warm cooling water to process bath
600 x 1000 x 20 =12,000,000
kcal/day
Efficiency of steam boiler 85 %
Calorific value of gas 8400 kcal/ Cub. M
Savings in natural gas 12,000,000/ (0.85x 8400)
=1,680 Cub. M /day
Annual gas savings @285 days operation per year 1,680 x 285
=478,800 Cub. M /year
Annual monetary savings @BDT 7.76 per Cub. M 478,800 x 7.76
=3,715,488 BDT
Investment for piping and controls near machine 1,000,000 BDT
Project lifetime 5 Years
Payback period 0.3 Year
IRR 933 %
NPV 11,681,616 BDT
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ECM 10: Recover heat from hot process baths (Effluent)
Production per day 20,000 kgs
Liquor ratio 1:6
No of process steps with hot discharges 5
Quantity of hot discharges 20,000 x 6 x 5/1000
=600 Cub. M /day
Average temperature of hot discharges 65 oC
Heat rejected by hot effluent to circulating water 600,000 x 1 x (65-35)
=18,000,000 kcal/day
Temperature rise in circulating water (55-30)
=25 oC
Amount of cooling water at 55oC per day 18,000,000/ (25 x 1000)
=720 Cub. M /day
Availability of warm water for process 720 Cub. M /day
Savings in natural gas 18,000,000/ (0.85x 8400)
=2,521 Cub. M /day
Annual gas savings @285 days per year 2521 x 285
=718,485 Cub. M /year
Annual monetary savings @BDT 7.76 per year 718,485 x 7.76
=5,575,443 BDT
Investment for heat exchanger, piping and controls near machine
1,000,000 BDT
Project lifetime 5 Years
Payback period 0.2 Year
IRR 1469 %
NPV 18,479,056 BDT
ECM 11: Reduce excess air in boiler by fine tuning the burner
Average steam production from two boilers 10,000 kgs/hr
Enthalpy of steam 600 kcal/kg
Efficiency of the boiler 84 %
Calorific value of gas 8400 kcal/Cub. M
Natural gas consumption 10,000 x 600/ (0.85 x 8400)
=840 Cub. M/hr
Average consumption per boiler 420 Cub. M/hr
Gas saving by reducing the excess air in one of the boilers28
420 x (12-4)/100 =33.6
Cub. M/hr
Annual gas saving @6,840 hours per year operation 33.6 x 6,840
=229,824 Cub. M /year
Annual monetary savings @BDT 7.76 per Cub. M 229,824 x 7.76
=1,783,434 BDT
Investment nil BDT
Project lifetime 5 Years
Payback period immediate Year
IRR - %
NPV - BDT
28 Every one percent reduction in oxygen will reduce gas consumption by 1%
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ECM 12: Preheat boiler feed water using the hot flue gases of the boiler through an economiser
Average exhaust temperature 180 oC
Gas consumption in boiler 840 Cub. M/hr
Quantity of steam generated in boiler ( two in operation @5 T/hr) 10 T/hr
Inlet temperature of boiler feed water without economiser 70 oC
Outlet temperature of the economizer feeding to the boiler 90 oC
Natural gas savings 10,000 x (90-70) /
(0.85 x 8400) =28
Cub. M/hr
Annual gas saving @6840 hours per year operation 28 x 6840 =191,520
Cub. M /year
Annual monetary savings @BDT 7.76 per Cub. M 191,520 x 7.76
=1,486,195 BDT
Investment 1,500,000 BDT
Project lifetime 5 Years
Payback period 1.2 Years
IRR 153 %
NPV 2,585,837 BDT
ECM 13: Optimisation of compressed air system
Reduction in power consumption by reducing pressure from 5-6 kg/cm2 to 3 kg/cm2 29
16 %
Power consumption for knitting with loading and unloading (0.6x75+0.4x25)
=55 Cub. M/hr
Power consumption with VFD 0.6 x 75
=45 kW
Savings due to VFD for knitting compressor 55-45
=10 kW
Savings due to pressure reduction for knitting 0.16 x 55
=8.8 kW
Total savings for knitting compressor 10+8.8 =18.8
kW
Savings @20 % for the centralised compressors assuming other than 75 kW compressors the remaining compressors will be operating without unloading
0.2 x 75 =15
kW
Total savings in compressed air system 18.8 + 15
=33.8 kW
Annual Electrical energy saving @6840 hours per year operation 33.8 x 6840
=231,192 kWh/year
Annual monetary saving @BDT 5.63 per kWh for GEG, BDT 8.15 per kWh for REB and BDT 20 per kWh for DG30
231,192 x (5.63 x 0.95 + 8.15 x 0.04 +
20 x 0.01) =1,358,137
BDT
Investment 1,000,000 BDT
Project lifetime 5 Years
Payback period 0.9 Year
IRR 257 %
NPV 3,066,383 BDT
29 Every 1 bar reduction in compressed air pressure reduces the power consumption by 8% 30 The plant uses GEG, REB and DG for power generation. 95% power is generated using GEG, 4% using REB and 1% using DG.
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ECM 14: Provide closed loop control for soft water pump
Power consumption for the soft water pump 30 kW
Average speed of operation expected with closed loop control of VFD
80 %
Power consumption with VFD 30 x (80%)3
=15 kW
Savings due to VFD with closed loop system 15 kW
Annual Electrical energy saving @6840 hours per year operation 15 x 6,840 =102,600
kWh/year
Annual monetary saving @BDT 5.63 per kWh for GEG, BDT 8.15 per kWh for REB and BDT 20 per kWh for DG31
102,600 x (5.63 x 0.95 + 8.15 x 0.04 +
20 x 0.01) =602,724
BDT
Investment 200,000 BDT
Project lifetime 5 Years
Payback period 0.4 Year
IRR 731 %
NPV 1,823,309 BDT
ECM 15: Provide VFD for cooling tower fan
Power consumption of each cooling tower fan 7.5 kW
Total load for all the three fans 22.5 kW
Expected energy reduction with VFD 20 %
Power Savings due to VFD 20% x 22.5
=4.5 kW
Annual Electrical energy saving 4.5 x 6840
=30,780 kWh/year
Annual monetary saving @BDT 5.63 per kWh for GEG, BDT 8.15 per kWh for REB and BDT 20 per kWh for DG32
30,780 x (5.63 x 0.95 + 8.15 x 0.04 + 20 x 0.01)
=180,817 BDT
Investment 250,000 BDT
Project lifetime 5 Years
Payback period 1.6 Years
IRR 77 %
NPV 186,544 BDT
31 The plant uses GEG, REB and DG for power generation. 95% power is generated using GEG, 4% using REB and 1% using DG. 32 The plant uses GEG, REB and DG for power generation. 95% power is generated using GEG, 4% using REB and 1% using DG.
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ECM 16: Relocate 50% of the lamps in the garment section to other parts of the plant
Power consumption of 4000 lamps @ 20 W per lamp 80 kW
Power savings by removing one lamp 40 kW
Power savings by replacing 2000 nos of 40 W lamps by the removed 20 W LED lamps
2000 x (40-20)/1000 =40
kW
Total power saving 80 kW
No of hours of lamp use in garments section 8 hours
Annual Electrical energy saving @ 8 hours per day and 285 days per year operation
80 x 8 x 285 =182,400
kWh/year
Annual monetary saving @BDT 5.63 per kWh for GEG, BDT 8.15 per kWh for REB and BDT 20 per kWh for DG33
182,400 x (5.63 x 0.95 + 8.15 x 0.04 + 20 x
0.01) =1,071,508
BDT
Investment nil BDT
Project lifetime 5 Years
Payback period Immediate Year
IRR - %
NPV - BDT
ECM 17: Replacement of old IE1/IE2 class motors by energy efficient IE3 class motors in Karim Spinning Mills Ltd
No. of old motors 500
Efficiency of old motors 79 %
Efficiency of new motors 86 %
Total rating of the motors 1100 kW
Annual savings @8000 hours per year operation 1100 x (1/0.79-1/0.86) x 8000
=906,682
kWh
Monetary savings @BDT 5.63 per kWh for GEG 906,682 x 5.63 =5,104,620
BDT
Investment @BDT 2,200 per kW 2,420,000 BDT
Project lifetime 5 Years
Payback period 0.6 Year
IRR 472 %
NPV 14,064,489 BDT
ECM 18: Install VFD for humidification pumps in Karim Spinning Mills Ltd
Total pump connected motors 30+22+45 =97
kW
Actual operating load 97 x 80% =77.6
kW
Conservative savings achievable 20 %
Energy savings 77.6 x 0.2 x 8000 =124,160
kWh
33 The plant uses GEG, REB and DG for power generation. 95% power is generated using GEG, 4% using REB and 1% using DG.
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd
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Monetary savings @BDT 5.63 per kWh for GEG 124,160 x 5.63 =699,020
BDT
Investment @BDT 7000 per kW 679,000 BDT
Project lifetime 5 Years
Payback period 1.1 Years
IRR 164 %
NPV 1,266,528 BDT
ECM 19: Improve existing lighting systems by energy efficient lamps in Karim Spinning Mills Ltd
No of existing lamps 450
Power consumption per lamp 36 W
Power consumption with LED 22 W
Annual energy savings 450 x (36-22) x 8000/1000
=50,400
kWh
Monetary savings @BDT 5.63 per kWh for GEG 50,400 x 5.63 =283,752
BDT
Investment 450,000 BDT
Project lifetime 5 Years
Payback period 1.8 Years
IRR 50 %
NPV 183,312 BDT
ECM 20: Reducing pressure of compressed air system and operating one compressor with VFD in Karim Spinning Mills Ltd
Number of compressors 4
Compressor rating 37 kW
Energy savings by pressure reduction of 1 bar34 37 x 4 x 8% =11.84
kW
Annual energy savings 11.84 x 8000 =94,720
kWh
Energy savings by avoiding power with VFD 20 %
Annual energy savings 37 x 4 x 20% x 8000 =236,800
kWh
Total energy savings 94,720 + 236,800 =331,520
kWh
Monetary savings @BDT 5.63 per kWh for GEG 331,520 x 5.63 =1,866,458
BDT
Investment 300,000 BDT
Project lifetime 5 Years
Payback period 0.2 Year
IRR 1655 %
NPV 6,252,073 BDT
34 Every 1 bar reduction in compressed air pressure reduces the power consumption by 8%
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ECM 21: Practice energy management
Annual NG use in GEG 10,845,057 Cub. M
Annual NG savings 2% at conservative scale 10,845,057 x 0.02 =216,901
Cub. M
Annual Monetary saving @BDT 9.62 per Cub. M 2,086,588 BDT
Investment 1,000,000 BDT
Project lifetime 5 Years
Payback period 0.6 Year
IRR 465 %
NPV 5,728,596 BDT
ECM 22: Install solar panel of 100 kW capacity for Purbani Fabrics Ltd, Purbani Yarn Dyeing Ltd and Karim Textiles Ltd
No of units per day 3.5 kWh/kW
Energy generation through solar @350 days/year 3.5 x 100 x 350 =122,500
kWh/year
Annual monetary saving @BDT 5.63 per kWh for GEG, BDT 8.15 per kWh for REB and BDT 20 per kWh for DG12
122,500 x (5.63 x 0.95 + 8.15 x 0.04 + 20 x 0.01)
=719,626
BDT
Investment @BDT 70,000 per kW 70,000 x 100 =7,000,000
BDT
Project lifetime 20 Years
Payback period 11.3 Years
IRR 4 %
NPV -4,354,969 BDT
ECM 23: Install solar panel of 100 kW capacity for Karim Spinning Mills Ltd.
No of units per day 3.5 kWh/kW
Energy generation through solar @350 days/year 3.5 x 100 x 350 =122,500
kWh/year
Monetary savings @BDT 5.63 per kWh for GEG 122,500 x 5.63 =689,675
BDT
Investment @BDT 70,000 per kW 70,000 x 100 =7,000,000
BDT
Project lifetime 20 Years
Payback period 11.7 Years
IRR 3 %
NPV -4,605,925 BDT
Investment Grade Energy Efficiency Assessment of Purbani Composite Textiles Ltd
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List of persons met/contacted for the investment grade energy audit
SL No
Contact Person Designation Contact No/ E-mail
Signature
01 Md. Golam Kabir Sr. AGM (Maintenance)
01712600569 golam.kabir @purbanigroup.com
02 Md. Aktar Hossain Sr. Manager 01738078701
03 Md. Mahmud Hasan Manager
Compliance 01975538057
04 A.K.M Nurul Islam DGM 01713228988
05 Sheikh Md. Shamim GM 01713228989
06 Ratan Kumar Roy Manager 01713228997
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Some machineries of the plant and the audit process