full report

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CONCEPTUAL DESIGN AND ECONOMIC ANALYSIS

FOR INTEGRATING SOLAR PV AND SOLAR

THERMAL SYSTEMS IN ELECTROPLATING

INDUSTRY

A SUMMER INTERNSHIP

PROJECT REPORT

Submitted by

ARAVINDH.M.A

as a part of

MASTER OF TECHNOLOGY

in

GREEN ENERGY TECHNOLOGY

CENTRE FOR GREEN ENERGY TECHNOLOGY

PONDICHERRY UNIVERSITY

PUDUCHERRY – 605014

JUNE - 2013

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ACKNOWLEDGEMENT

First, foremost I thank God Almighty for his grace in enabling me to

complete this project work in successful way.

I thank my Centre Head Dr. P.ELUMALAI., Centre for Green Energy

Technology, Pondicherry University for permitting me to do this project and

for his guidance.

I also thank all faculty and non teaching staffs of Centre for Green Energy

Technology, Pondicherry University for their support.

I also thank Mr. Bhoovarahan Thirumalai, CEO, Aspiration Energy and his

colleuge for letting me to do the project in his organisation.

I also like to spell our sincere thanks to my parents and friends for their

support and encouragement.

M.A.ARAVINDH

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ABSTRACT

Development in solar energy utilization has been booming day after day and

hence utilizing it for different applications is much welcomed now a days.

Industries are direct market for such applications. Solar power can be

utilized for producing electricity and heating applications using solar PV and

solar thermal technologies respectively. In this project, electroplating is

studied for finding the possibility of integrating solar power into the current

process. Conceptual design is made for integrating solar power systems to

the industry and its approximate economic analysis is done.

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TABLE OF CONTENTS

CHAPTER NO. TITLE PAGE NO.

ABSTRACT iii

LIST OF TABLES v

LIST OF FIGURES v

1 INTRODUCTION 1

1.1 SOLAR POWER 1

1.1.1 SOLAR PV SYSTEMS 1

1.1.2 SOLAR THERMAL SYSTEMS 4

1.2 ELECTROPLATING INDUSTRY 7

1.3 INDUSTRIAL PROCESS HEATING 9

1.4 INTEGRATING SOLAR POWER 10

INTO INDUSTRIAL PROCESSES

1.5 ECONOMIC CONSIDERATION 12

2 LITERATURE REVIEW 13

3 METHODS AND METHODOLOGY 14

3.1 COMPANY PROFILE 14

3.2 SYSTEM CONCEPTUAL DESIGN 14

3.2.1 SOLAR THERMAL SYSTEM 15

3.2.2 SOLAR PV SYSTEM 15

4 RESULTSAND DISCUSSIONS 16

4.1 ECONOMIC ANALYSIS 16

5 CONCLUSION 17

REFERENCES 18

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List of Figures

Figure 1 Functioning of the photovoltaic cell 2

Figure 2 Parabolic trough 4

Figure 3 Central Receiver or Solar Tower 5

Figure 4 Parabolic Dish 6

Figure 5 ETHP 7

Figure 6 Electroplating Process 8

Figure 7 Electroplating industry process 8

Figure 8 Solar thermal energy feeding into the existing 11

hot water system

Figure 9 Conceptual design 14

List of Tables

Table1 Basic parameters of electroplating baths 9

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1. INTRODUCTION

1.1 SOLAR POWER

The sun is the central star of the solar system in which the Earth is. It has a

form of a large glowing ball of gas, the chemical composition of mostly

hydrogen and helium, but also other elements that are in it to a lesser extent,

like oxygen, carbon, iron, neon, nitrogen, silicon, magnesium and sulphur.

Energy from the Sun comes to the Earth in the form of solar radiation.

Nuclear reactions take place in the interior of the Sun, during which

hydrogen is transformed into helium by a fusion process, accompanied by

the release of large amounts of energy, where the temperature reaches 15

million °C. Part of this energy comes to Earth in form of heat and light, and

allows all processes, from photosynthesis, production of electricity in

photovoltaic systems, heating in solar thermal systems.

Under optimal conditions, the earth's surface can obtain 1.000 W/m2, while

the actual value depends on the location, i.e. latitude; climatological location

parameters such as frequency of cloud cover and haze, air pressure, etc.

Harvesting solar power can be done in two ways

Solar to electricity - Solar PV

Solar to heat - Solar Thermal

1.1.1 SOLAR PV SYSTEMS

Converting solar energy into electrical energy by PV installations is the most

recognized way to use solar energy. Solar photovoltaic modules, which are a

result of combination of photovoltaic cells to increase their power, are highly

reliable, durable and low noise devices to produce electricity. The fuel for

the photovoltaic cell is free. Sun is the only resource that is required for the

operation of PV systems, and its energy is almost inexhaustible. Typically

photovoltaic cell efficiency is about 15-20%, which means it can convert 1/6

of solar energy into electricity. Photovoltaic systems produce no noise, there

are no moving parts and they do not emit pollutants into the environment.

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Taking into account the energy consumed in the production of photovoltaic

cells, they produce several tens of times less carbon dioxide per unit in

relation to the energy produced from fossil fuel technologies. Photovoltaic

cell has a lifetime of more than thirty years and is one of the most reliable

semiconductor products. Most solar cells are produced from silicon, which is

non‐toxic and is found in abundance in the earth's crust.

FUNCTIONING OF THE PHOTOVOLTAIC CELL

PV junction (diode) is a boundary between two differently doped

semiconductor layers; one is a P‐type layer (excess holes), and the second

one is an N‐type (excess electrons). At the boundary between the P and the

N area, there is a spontaneous electric field, which affects the generated

electrons and holes and determines the direction of the current.

Figure 1 Functioning of the photovoltaic cell

To obtain the energy by the photoelectric effect, there shall be a directed

motion of photoelectrons, i.e. electricity. All charged particles,

photoelectrons also, move in a directed motion under the influence of

electric field. The electric field in the material itself is located in

semiconductors, precisely in the impoverished area of PV junction (diode). It

was pointed out for the semiconductors that, along with the free electrons in

them, there are cavities as charge carriers, which are a sort of a by product in

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the emergence of free electrons. Cavities occurs whenever the valence

electron turns into a free electron, and this process is called the generation,

while the reverse process, when the free electron fills the empty spaces ‐ a

cavity, is called recombination. If the electron‐cavity pairs occur away from

the impoverished areas it is possible to recombine before they are separated

by the electric field.

Photoelectrons and cavities in semiconductors are accumulated at opposite

ends, thereby creating an electromotive force. If a consuming device is

connected to such a system, the current will flow and we will get electricity.

In this way, solar cells produce a voltage around 0.5‐0.7 V, with a current

density of about several tens of mA/cm2 depending on the solar radiation

power as well as on the radiation spectrum.

TYPES OF SOLAR PHOTOVOLTAIC CELLS

Electricity is produced in solar cells which, as noted, consist of more layers

of Semi conductive material. When the sun's rays shine down upon the solar

cells, the electromotive force between these layers is being created, which

causes the flow of electricity. The most common material for the production

of solar cells is silicon. Silicon is obtained from sand and is one of the most

common elements in the earth's crust, so there is no limit to the availability

of raw materials. Solar cell manufacturing technologies are:

• Monocrystalline. •Thin-film technology.

•Polycrystalline. •Polymer based solar cell.

PHOTOVOLTAIC SYSTEM TYPES

Photovoltaic systems can be generally divided into two basic groups:

1. Photovoltaic systems not connected to the network, stand‐alone

systems (off‐grid)

2. Photovoltaic systems connected to public electricity network

(on‐grid)

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1.1.2 SOLAR THERMAL SYSTEMS

Solar thermal power is a relatively new technology which has already shown

enormous promise. With few environmental impacts and a massive resource,

it offers a comparable opportunity to the sunniest countries of the world as

offshore wind farms are currently offering to European nations with the

windiest shorelines. Solar thermal power uses direct sunlight, so it must be

sited in regions with high direct solar radiation.

Solar thermal power plants, often also called Concentrating Solar Power

(CSP) plants, produce electricity in much the same way as conventional

power stations. The difference is that they obtain their energy input by

concentrating solar radiation and converting it to high-temperature steam or

gas to drive a turbine or motor engine. Four main elements are required: a

concentrator, a receiver, some form of transport media or storage, and power

conversion. Many different types of systems are possible, including

combinations with other renewable and non-renewable technologies, but the

most promising solar thermal technologies are:

PARABOLIC TROUGH

Figure 2: Parabolic trough

Parabolic trough-shaped mirror reflectors are used to concentrate sunlight on

to thermally efficient receiver tubes placed in the trough’s focal line. A

thermal transfer fluid, such as synthetic thermal oil, is circulated in these

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tubes. Heated to approximately 400°C by the concentrated sun’s rays, this

oil is then pumped through a series of heat exchangers to produce

superheated steam. The steam is converted to electrical energy in a

conventional steam turbine generator, which can either be part of a

conventional steam cycle or integrated into a combined steam and gas

turbine cycle.

CENTRAL RECEIVER OR SOLAR TOWER

Figure 3: Central Receiver or Solar Tower

A circular array of heliostats (large individually tracking mirrors) is used to

concentrate sunlight on to a central receiver mounted at the top of a tower. A

heat-transfer medium in this central receiver absorbs the highly concentrated

radiation reflected by the heliostats and converts it into thermal energy to be

used for the subsequent generation of superheated steam for turbine

operation. To date, the heat transfer media demonstrated include

water/steam, molten salts, liquid sodium and air. If pressurised gas or air is

used at very high temperatures

of about 1,000°C or more as the heat transfer medium, it can even be used to

directly replace natural gas in a gas turbine, thus making use of the excellent

cycle (60% and more) of modern gas and steam combined cycles.

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PARABOLIC DISH

A parabolic dish-shaped reflector is used to concentrate sunlight on to a

receiver located at the focal point of the dish. The concentrated beam

radiation is absorbed into the receiver to heat a fluid or gas (air) to

approximately 750°C. This fluid or gas is then used to generate electricity in

a small piston or Stirling engine or a micro turbine, attached to the receiver.

Figure 4: Parabolic Dish

ETHP

Evacuated Tube Heat Pipe (ETHP) is composed of multiple

evacuated glass tubes each containing an absorber plate fused to a heat

pipe. The heat from the hot end of the heat pipes is transferred to the transfer

fluid (antifreeze mix—typically propylene glycol) hydronic space heating

system in a heat exchanger called a "manifold”. The vacuum that surrounds

the outside of the tube greatly reduces convection and conduction heat loss

to the outside.

Glass evacuated tubes are the key component of the Evacuated Tube Heat

Pipe solar collectors. Each evacuated tube consists of two glass tubes. The

outer tube is made of extremely strong transparent borosilicate glass. The

inner tube is also made of borosilicate glass, but coated with a special

selective coating, which features excellent solar heat absorption and minimal

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heat reflection properties. Evacuated tube heat pipe collectors use a copper

pipe attached to an absorber plate, inside a vacuum sealed solar tube.

The heat pipe is hollow and the space inside is also evacuated inside the heat

pipe is a small quantity of liquid, such as alcohol or purified water plus

special additives. The vacuum enables the liquid to boil at lower temperature

than it would be at normal atmospheric pressure. When sunlight falls on the

surface of the absorber, the liquid in the heat tube quickly turns to hot vapor

and rises to the pipe. Water glycol flows back down the tube. This process

continues, as long as the sun shines. Since there is a “Dry” connection

between the absorber and header installation, it is much than the direct flow

collectors. Individual tubes can also be exchanged without emptying the

entire system of its fluid and should one tube break, there is little impact on

the complete system.

Figure 5: ETHP

1.2 ELECTROPLATING INDUSTRY

Electroplating is an electro deposition process for producing a dense,

uniform, and adherent coating, usually of metal or alloys, upon a surface by

the act of electric current. The coating produced is usually for decorative

and=or protective purposes, or enhancing specific properties of the surface.

The surface can be conductors, such as metal, or non-conductors, such as

plastics. Electroplating products are widely used for many industries, such as

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automobile, ship, air space, machinery, electronics, jewellery, defence, and

toy industries. The core part of the electroplating process is the electrolytic

cell (electroplating unit). In the electrolytic cell (electroplating unit) a

current is passed through a bath containing electrolyte, the anode, and the

cathode. In industrial production, pre-treatment and post-treatment steps are

usually needed as well.

Figure 6: Electroplating Process.

Figure 7: Electroplating industry process

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Table1: Basic parameters of electroplating baths.

1.3 INDUSTRIAL PROCESS HEATING

Process heating is essential in the manufacture of most consumer and

industrial products, including those made out of metal, plastic, rubber,

concrete, glass, and ceramics. Process heating systems can be broken into

three basic categories:

(a) Fuel-based process heating with fuel-based systems, heat is

generated by the combustion of solid, liquid, or gaseous fuel, and transferred

either directly or indirectly to the material. The combustion gases can be

either in contact with the material (direct heating), or be confined and thus

be separated from the material (indirect heating, e.g., radiant burner tube,

retort, muffle). Examples of fuel-based process heating equipment include

furnaces, ovens, kilns, etc.

(b) Electric-Based Process Heating Electric-based process heating

systems (sometimes called electro technologies) use electric currents or

electromagnetic fields to heat materials. Direct heating methods generate

heat within the work piece, by either (1) passing an electrical current through

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the material, (2) inducing an electrical current (eddy current) into the

material, or (3) exciting atoms and/or molecules within the material with

electromagnetic radiation (e.g., microwave). Indirect heating methods use

one of these three methods to heat an element, which transfers the heat to the

work piece by either conduction, convection, radiation, or a combination of

these.

(c) Steam-Based Process Heating Steam has several favourable

properties for process heating applications. Since most of the heat content of

steam is stored as latent heat, large quantities of heat can be transferred

efficiently at a constant temperature, which is a useful attribute in many

process heating applications. Steam-based process heating has low toxicity,

ease of transportability, and high heat capacity.

Hybrid systems use a combination of process heating systems by using

different energy sources or different heating methods of the same energy

source. Electric infrared, in combination with either an electric convection

oven or a gas convection oven is a hybrid system.

1.4 INTEGRATING SOLAR POWER INTO INDUSTRIAL PROCESSES

Integration of solar power to industry can be done in for their major

requirements such as heat and electricity. Both the requirements can be met

using solar PV and solar thermal technologies.

For integrating solar PV system, their electricity requirement and the

available spacing are the factors to be considered. Power requirement is

calculated for the entire load to be connected to the system for the operation

of the industry. Also for the same power requirement there should be

sufficient area for erection of PV systems. The cost consideration is done by

the requirement of the industry whether they need a standalone system or a

grid connected or with or without battery backup.

The integration of solar heat into industrial production processes is a

challenge to both: the process engineer and the solar expert. Usually the

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thermal solar system will be only a part of the total process energy system

and will supply only a fraction of the total energy demand.

Existing heating system – based on steam or hot water from a boiler – don’t

have to take care of temperature level too much. In general they are designed

at much higher temperatures compared to what the processes need in order

to keep temperature differences – and by that heat exchanger surfaces –

small. Very often we can find steam temperatures at 150 to 180°C while the

processes run below 100°C or even much lower. Applying solar heat, much

more attention has to be paid to the temperature levels.

Another challenge in applying solar thermal energy to industrial production

processes is the time dependency of the solar energy supply and the heat

demand of the processes. Only very few production lines run at constant

loads all over the day. Most processes in smaller companies run for one or

two shifts per day and are batch processes by themselves. Direct process

heating or feeding into existing heating system. The easiest way of

integrating solar thermal heat into industrial energy systems, is to supply it

to the existing heating system. In that case, the solar collector has to be

operated at the same temperature level as the existing heating system, which

will be above 100°C in general. The heat transfer medium should be water

and not steam if possible. Such a set up is easy to install and to control, but

the thermal efficiency will be low.

Figure 8: Solar thermal energy feeding into the existing hot water system

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1.5 ECONOMIC CONSIDERATION

In industry the demands on the economic performance of investments

usually is very high. Payback times of 3 years and less are required for

production equipment, but 10 years are accepted for infrastructure as

buildings and energy systems. Such numbers are difficult to obtain with

solar systems if energy savings are considered as the only benefits but there

exist examples that it is possible even at present energy and equipment

prices. There are also new and promising considerations offering solar-

contracting solutions to industry. In these contracting models, the solar

energy supplier takes the investment costs of the solar equipment and the

enterprise pays for the energy delivered.

Looking closer to the energy systems of industrial installations, one can find

other options for energy conservation or energy efficiency in many cases.

Heat exchange can provide low temperature heat from outgoing process

streams. Cogeneration with gas turbines, steam turbines and/or diesel motors

provides low temperature heat at reasonable prices as well. More than this,

new technological developments can shift the energy demand from heat to

power and will change the future demands. But there is a market for solar

thermal energy in the process industry as soon as strategic considerations are

being made in addition to simple payback calculations. Investments in

sustainable solutions like solar energy will improve the supplier’s position in

the market through image gained, through increased workers engagement

and a long term stability of energy prices.

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2. LITERATURE REVIEW

[1] Solar thermal systems can be utilized for industrial applications like

process heating, drying etc. Various technologies like ETC, ETHP, Parabolic

Concentrators etc are used for this.

[2, 3] Process heating is mostly essential for industries like rubber, paper,

etc. Most of the heating source will be fuel based, electric based or steam

based. Approaches to improve a certain heating operation might be

applicable to multiple processes, but may be unknown within and/or outside

a given industry segment.

[4, 5] Electroplating process requires heating and DC supply based on the

type of plating. Heating is not much required, but the DC supply is the major

requirement and the source of electroplating process.

[6] Cost analysis for renewable energy systems has been well explained by

the IRENA in the cost analysis series explaining the different considerations

to be made while cost analysis. Considerations to be taken are system cost,

installation cost, labour cost and maintenance cost

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3. METHODS AND METHODOLOGY

The project is done by taking a company as an example for understanding

the process and requirement and hence focussing on possibility of

integration of solar power to electroplating industry

3.1 COMPANY PROFILE

Company Name : GRG Designs.

Products : Electroplating (Nickel and Alkaline).

Area Available : 800 Sq. Ft.

Requirements

1. Temperature : 60o to 80

o C.

2. Rectifying Load

Voltage : 5 to 7 V

Current : 100 to 500 A

3.2 SYSTEM CONCEPTUAL DESIGN

Figure 6: Conceptual design

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Conceptual Design for integrating solar thermal and solar PV into the

Electroplating Industrial will completely replace power requirement for

heating and rectifying load.

3.2.1 SOLAR THERMAL SYSTEM

In the solar thermal system, a copper coil is used as a heat transfer system in

which the Heat Transfer Fluid (HTF) will be flowing. The flow is

maintained using a pump for regulating the required temperature and proper

heat transfer. The pump is operated with a microcontroller, which gets a feed

from a thermocouple from the chemical bath. The microcontroller is

calibrated for the required temperature, say 70oC. Depending on the

temperature variation of the bath, the pump will be worked to maintain the

bath temperature as 70oC. Hence the functioning of the pump is automated to

maintain the required temperature.

3.2.2 SOLAR PV SYSTEM

Solar PV system in here is a very simple system with no backup system and

inverter. Based on the requirement, solar PV panels are erected and through

controller the power is directly used because the requirement is DC power.

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4. RESULTSAND DISCUSSIONS

By integrating solar thermal and solar PV system for electroplating industry

can dramatically bring down the running cost because most of the industries

use electric heaters for heating the bath.

4.1 ECONOMIC ANALYSIS

FOR HEATING

Total Heating Load : 14 KW

Average Usage Hours : 5 hrs

No. of Working Hours/Month : 25

Cost/Unit : Rs.7.75

Total Cost/ Year : Rs.1, 62,750

DC POWER

Total Load : 5.7 KW

Average Usage Hours : 5 hrs

No. of Working Hours/Month : 25

Cost/Unit : Rs.7.75

Total Cost/ Year : Rs.66, 262

Net Cost for Running : Rs.2, 29,012

INSTALLATION COST (approximate)

Thermal System (1000LPD) : Rs.1, 00, 000

PV System (6 KW) : Rs.6, 00, 000

Total Cost : Rs.7, 00, 000

Approximate Payback Period : 3 Years

Even though the initial investment is high, the investment can be got back in

a very short period.

POSSIBLE SYSTEM IMPROVEMENTS

A heat sink can be used for storing heating for prolonged usage.

A battery back system can help in utilizing the power during night

also.

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5. CONCLUSION

The major requirements for the industry, heat and DC power, can be directly

given using solar thermal and solar PV systems respectively. Integrating

solar power to electroplating industry will dramatically bring down the

power expenses because of the proper utilization of the technology.

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REFERENCES

[1] Page 93-103, solar thermal applications, Centre for Study of Science,

Technology and Policy (CSTEP).

[2] Improving Process Heating System Performance: A Sourcebook for

Industry, Second Edition, National Renewable Energy Laboratory Golden,

Colorado.

[3]Solar heat for industrial processes – Potential, technologies and

applications, Klaus Vajen, Christoph Lauterbach, Bastian Schmitt,Kassel

University, Institute of Thermal Engineering, Kassel (Germany).

[4] Electroplating, Pollution Prevention and Abatement Handbook, WORLD

BANK GROUP.

[5] Electroplating, Helen H. Lou, Department of Chemical Engineering,

Lamar University, Beaumont, Texas, U.S.A.

[6] Renewable energy technologies: cost analysis series, Volume 1: Power

Sector, Issue 4/5, IRENA working paper.