SUMMER INTERNSHIP REPORT

A Technical Guide on

“Utilization of Concentrated Solar Technology for

Industrial and Commercial Applications”

UNDER THE GUIDANCE OF

Mr K. P. S. Parmar, Asst. Director, CAMPS, NPTI

&

Dr. Sudhir Kumar, Joint Director & Head, Centre for Solar Energy

At

WISE, Pune

Submitted by

Lokesh Jaiswal

ROLL NO: 43

MBA (POWER MANAGEMENT)

(Under the Ministry of Power, Govt. of India)

Affiliated to

MAHARSHI DAYANAND UNIVERSITY, ROTHAK

AUGUST 2013

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DECLARATION

I, LOKESH JAISWAL, Roll No 43, student of MBA-Power Management (2012-14) at

National Power Training Institute, Faridabad hereby declare that the Summer Training Report

entitled “Utilization of Concentrated Solar Technology for Industrial and Commercial

Applications” is an original work and the same has not been submitted to any other Institute

for the award of any other degree.

A Seminar presentation of the Training Report was made on

________________________ and the suggestions as approved by the faculty were duly

incorporated.

Project In-Charge

(Faculty)

Countersigned

Signature of Candidate

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ACKNOWLEDGEMENT

I would like to extend warm thanks to all the people who had been associated with me in

some way or the other and helped me avail this opportunity for my summer Internship on the

topic

“Utilization of Concentrated Solar Technology for Industrial and Commercial

Applications”

I would like to thank Mr. G.M Pillai, Director General WISE, for giving me the opportunity

for pursuing my summer internship in the learning environment of WISE. I sincerely thank

my project mentor Dr. Sudhir Kumar, Joint Director & Head, Centre for Solar Energy, for

providing me with valuable insights on the project, correcting me and guiding me throughout

the project. I am also thankful to Mr.Prabhuram, Senior Research associate, Mangesh

Ghungrud, Senior Research associate and Nandkishor Dhakate, Senior Research associate

and Jacob John, Sr. Executive for their constant support and guidance. I would also express

my regards for Mr. Arun Mehta, Senior research associate, Mr. Gaurav Jain, Research

associate and Mr. Chandan Kumar, Research associate for their timely support.

I express my gratitude to my college authority and Mr. J S S Rao (Principal Director), Mr.

S.K. Choudhary, Principal Director (CAMPS) and Mrs. Manju Mam, Dy. Director NPTI

for arranging my summer internship program with World Institute of Sustainable Energy,

Pune. I would also like to thank my internal guide Mr. K.P.S. Parmar, Asst. Director NPTI

for his assistance. Last but not the least I express my thanks to all the staff at WISE, from all

departments I got in touch with, who have been very cooperative, helpful, kind and

empathetic; time and again, without whom this dissertation would not have been possible.

Lokesh Jaiswal

Student,

MBA, Power Management

iii

Executive Summary

At present in the world most of the power generated nowadays is produced by using fossil

fuels, which emit tons of carbon dioxide and other pollution every second. More importantly,

fossil fuel will eventually run out. In order to make the development of our civilization

sustainable and cause less harm to our environment, people are looking for new source of

substitute clean energy.

Because of the increasing demands in clean energy, the solar energy industry is one of the

fastest growing forces in the market. Nowadays there are several major directions for solar

technology development. For example, photovoltaic systems directly convert the solar energy

into electrical energy while concentrated solar power systems first convert the solar energy

into thermal energy and then further convert it into electrical energy through a thermal

engine. Another area which is having tremendous potential for using solar energy is thermal

heat applications in different industries.

The potential for solar energy has been estimated for most parts of the country at around 30-

50 MW per square kilometre of open, shadow free area covered with solar collectors and 300

sunny days in a year, India’s potential for harnessing solar power is immense. But due to lack

of conducive policy scenario till some years back, the share of solar energy in total renewable

power generation stands at a very low level. Some of the key initiatives such as Indian Solar

Loan Programme initiated in 2003 by partnership of Indian banking groups with UNEP and

Jawaharlal Nehru National Solar Mission (JNNSM) initiated in 2010 by the Government

of India gave a major thrust to the Solar power developments thereafter.

There are four solar thermal technologies currently being used in India: parabolic troughs,

solar towers, and parabolic dish and linear frensel reflector. Because these technologies

involve a thermal intermediary, they can be readily hybridized with fossil fuel and in some

cases adapted to utilize thermal storage. Scheffler and Arun are dominating technology in

India. Many organisations have installed this technology as alternative source of energy

which is not only helpful in their cost saving but also it keeps environment clean and healthy.

This report not only gives a brief introduction about the fast developing solar thermal

technologies, but also may help to identify the factors and barriers which are hindering the

growth of solar thermal technology.

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Table of Contents

DECLARATION ........................................................................................................................ i

ACKNOWLEDGEMENT ......................................................................................................... ii

Executive Summary ................................................................................................................. iii

List of Figures ........................................................................................................................... vi

List of Tables ............................................................................................................................ vi

Chapter 1: Introduction .............................................................................................................. 1

Chapter 2: Applications of Concentrated Solar Technology .................................................... 2

2.1.1 Solar Water Heating ................................................................................. 3

2.1.2 Solar Drying ........................................................................................... 4

2.1.3 Solar Cooking ......................................................................................... 6

2.1.4 Solar Space Heating ................................................................................. 6

2.1.5 Solar cooling .......................................................................................... 7

2.1.7 Solar Distillation ..................................................................................... 9

2.2 Industrial Applications of Solar Heat ............................................................... 10

Chapter 3: Concentrated Solar Technology ............................................................ 13

2.1 Solar Energy Resources ................................................................................ 13

2.2 Basic Principles ........................................................................................... 13

3.3 Types of Technology .................................................................................... 14

3.4 Design Parameters ....................................................................................... 18

Chapter 4: Heat and Its Measurement ...................................................................................... 20

4.1 Basic terms ................................................................................................. 20

4.2 Measurement of heat for generating steam ........................................................ 23

4.3 ARUN Dish ................................................................................................ 26

4.4 Scheffler Dish ............................................................................................. 28

4.5 Indian Boiler Regulations .............................................................................. 29

Chapter 5: Financial Viability .................................................................................................. 30

5.1 Calculations of Payback Period ...................................................................... 30

5.2 Cost of Installation ....................................................................................... 31

5.3 Comparison between Arun and Scheffler dish ................................................... 32

Chapter 6: Environment Benefits of Using Concentrated Solar System ................................. 33

Chapter 7: Barriers ................................................................................................................... 35

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7.1 Cost .......................................................................................................... 35

7.2 Variability .................................................................................................. 35

7.3 Process Integration ....................................................................................... 36

7.4 Energy Storage Options ................................................................................ 36

Chapter 8: Conclusion.............................................................................................................. 37

FOUR SUCCESS STORIES OF CST INSTALLATIONS IN INDIA .................................. 39

1. SHIRDI SOLAR STEAM COOKING SYSTEM ........................................................... 39

2. CSM HOSPITAL, THANE ............................................................................................. 44

3. Gajraj Dry cleaners, Ahmednagar .................................................................................... 49

4. ITC Maurya ...................................................................................................................... 52

Bibliography ............................................................................................................................ 56

vi

List of Figures

Figure 1: Types of solar thermal technology ............................................................................. 2

Figure 2: Parabolic trough ....................................................................................................... 15

Figure 3: Parabolic dish ........................................................................................................... 15

Figure 4: Solar tower ............................................................................................................... 16

Figure 5: Linear Frensel Reflector ........................................................................................... 17

Figure 6: Phase change ............................................................................................................ 21

Figure 7: Vapour dome ............................................................................................................ 21

Figure 8 : Diffuse and Direct Solar Radiation ......................................................................... 22

Figure 9: Latent heat of vaporization ....................................................................................... 24

Figure 10: Arun Dish ............................................................................................................... 27

Figure 11: Scheffler dish .......................................................................................................... 29

Figure 12: Solar system in Shirdi ............................................................................................ 41

Figure 13: Solar system in CSM Thane ................................................................................... 47

Figure 14: Solar system in Gajraj Drycleaners ........................................................................ 49

Figure 15: Solar system in the roof of ITC Maurya................................................................. 52

List of Tables

Table 1: Technical Specification of Arun dishes ..................................................................... 27

Table 2: Specifications of Shirdi solar system ......................................................................... 42

Table 3: Cost of existing energy system in CSM Thane ......................................................... 45

Table 4: Capital Structure of CSM Thane ............................................................................... 47

Table 5: Payback period of solar system in CSM Thane ......................................................... 47

Table 6: Technical specification of solar system in Gajraj drycleaners .................................. 51

Table 7: Performance parameters of solar system ................................................................... 54

Table 8: Details of solar system in ITC Maurya ...................................................................... 54

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Chapter 1: Introduction

Energy is the basis of human life. With increasing population and energy demand along with

challenges posed by climate change, also increasing import dependency with rise in fossil

fuel prices is putting huge pressure in finding the clean energy source to fulfil the demand.

According to world report 80% of energy demand is fulfilled by fossil fuel resources such as

oil, gas and coal. It is well known fact that these resources will be exhausted one day. It is a

need of today’s world to focus on renewable energy resources such as wind, solar, tidal etc.

Sun is the source of all form of energy available on the earth. Solar energy is the energy force

that sustains life on the earth for all plants, animals, and people. The earth receives this

radiant energy from the sun in the form of electromagnetic waves, which the sun continually

emits into space. The earth is essentially a huge solar energy collector receiving large

quantities of this energy which manifests itself in various forms, such as direct sunlight used

through photosynthesis by plants, heated air masses causing wind, and evaporation of the

oceans resulting as rain which can form rivers. This solar energy can be tapped directly as

solar energy (thermal and photovoltaic), and indirectly as wind, biomass, waterpower, wave

energy, and ocean temperature difference. It is the most resourceful energy which can be

termed as future energy.

Solar energy can be harnessed by two methods, solar thermal and solar photovoltaic in which

sun rays can be directly converted into electricity. The concentrated solar technology (CST)

is comparatively new and market is slowly developing for using this technology. Many

industrial and commercial applications such as cooking, comfort cooling, space heating etc.

require heat at less than 300°C which can be easily fulfilled by CST.

India is a country where demand exceeds supply. At present the energy deficit stands at 8.7%

for 2013-14. Industrial energy consumption is responsible for 28 % of India’s total energy

consumption. If industries opt for CST for their various applications, not only it will help to

minimize the power deficit condition but also it is very useful for our environment. India has

enormous potential for solar power. It is among the most promising area in the world in solar

energy field. Solar energy development in India can be very important tool not only for

economic development of the country but also it will reduce the pollution level of country by

reducing CO2 emission. Thus it will have positive impact on our environment.

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Chapter 2: Applications of Concentrated Solar Technology

The concentrated solar technology is relatively new. With few environmental impacts and a

massive resource, it offers a comparable opportunity to the sunniest countries of the world.

And India is one of such country. The solar thermal applications have great potential in our

country. The Technical potential for India is about 5,000 trillion KWh per Year. That means

it receives radiation of 4 to 7 kWh/m2/day. Thus India has the natural advantage of

harnessing solar energy with approximately 300 sunny days on average. India is targeting to

harness 20 million m2 of solar thermal collector area by 2022 through Jawahar Lal Nehru

National Solar Mission.

Solar thermal technology harnesses solar energy into thermal energy for non-electrical

applications and is already a mature and economically viable option.

The majority of the solar thermal technologies operating today provide hot water to

households for both sanitary purposes and space heating. While solar water heating is well

established, it is crucial that the potential of solar thermal technology in other applications in

the residential and industrial sectors are analysed as well. In the residential sector, solar

cooking has the potential to reduce the use of traditional firewood and biomass. In the

industrial sector, process heat is used in multiple industries, such as, food (for cleaning,

drying and pasteurization), machinery and textile (for cleaning and drying). Approximately

85% of the heat energy used in industry is below 400°C. Given the demand for heat at low to

medium temperatures, the potential use of solar energy is enormous.

Figure 1: Types of solar thermal technology

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2.1 Scope of Solar Thermal Energy

Water Heating

Drying

Cooking

Space Heating

Refrigeration and Air Conditioning,

Distillation

2.1.1 Solar Water Heating

Solar water heating is the simplest way of harnessing solar energy. It is the most competitive

to alternate method of water heating such as electric geysers and fuel-fed boilers. It makes an

attractive and sustainable option, with its global distribution, pollution free nature, virtually

inexhaustible supply and near-zero operational cost. Solar water heaters run on a free fuel

(i.e. sunshine), thus saving on energy costs that help recover its initial cost in just 2-4 years.

A solar water heater consists of a collector to collect solar energy and an insulated storage

tank to store hot water. A black absorbing surface (absorber) inside the collectors absorbs

solar radiation and transfers the heat energy to water flowing through it. Heated water is

collected in a tank which is insulated to prevent heat loss. After this hot water from storage

tank is distributed through pipe for various applications. The total system with solar

collector, storage tank and pipelines is called solar hot water system.

Broadly, solar water heating systems are of two categories: closed loop system and open loop

system. In the first one, heat exchangers are installed to protect the system from hard water

obtained from bore wells or from freezing temperatures in cold regions. In the other type,

either thermo siphon or forced circulation system, the water in the system is open to the

atmosphere at one point or another. The thermo siphon systems are simple and relatively

inexpensive. They are suitable for domestic and small institutional systems, provided the

water is treated and is potable in quality. The forced circulation systems employ electrical

pumps to circulate the water through collectors and storage tanks. The choice of system

depends on the heat requirement, weather condition, heat transfer fluid quality, space

availability, annual solar radiation etc.

4

Water heating is one of the most cost-effective uses of solar energy, providing hot water for

showers, dishwashers and clothes washers. Every year, several thousands of new solar water

heaters are installed worldwide. Solar water heaters can be used for homes, community

centres, hospitals, nursing homes, hotels, restaurants, dairy plants, swimming Pools, canteens,

ashrams, hostels, industry etc. Use of solar water heater can help to reduce electricity or fuel

bills considerably.

Examples of Solar Water Heat Applications

The system has been installed on top of the terrace of a 20 storied high rise building

of Reserve Bank of India in Lower Parel, Mumbai with a capacity of 10000 liters/day

of hot water supply.

Magarpatta is one of the biggest housing complexes in India covering over 550 acres.

And each house is equipped with solar water heating system.

Solar water heating systems is being used efficiently for swimming pool heating in

the Golf-Club of Chandigarh which has a capacity of 6 lakhs liter.

Solar water heating is now a mature technology. Widespread utilization of solar water heaters

can reduce a significant portion of the conventional energy being used for heating water in

homes, factories and other commercial and institutional establishments. Internationally, the

market for solar water heaters has expanded significantly during the last decade

2.1.2 Solar Drying

Solar drying is a method in which the solar energy is used to dry substances and to preserve

agriculture based food and non-food products. Drying under sunlight is the oldest way to

harness sun energy. This form of energy is free, renewable and abundant in any part of the

world especially in tropical countries. However, to maximize its usage and to optimize

efficiency of drying using solar radiation, appropriate technology need to be applied in order

to keep this technique a sustainable one. Such technology is known as solar drying and is

becoming a popular option to replace mechanical thermal dryers owing to the high cost of

fossil fuels which is growing in demand but declining in supply. For sustainability and

climate change concerns it is important to use renewable energy as much as possible.

Preservation of fruits, vegetables, and food are essential for keeping them for a long time

without further deterioration in the quality of the product. Several process technologies have

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been employed on an industrial scale to preserve food products; the major ones are freezing,

and dehydration. Among these, drying is especially suited for developing countries with

poorly established low-temperature and thermal processing facilities. It offers a highly

effective and practical means of preservation to reduce post- harvest losses and offset the

shortages in supply. Drying is a simple process of moisture removal from a product in order

to reach the desired moisture content and is an energy intensive operation.

Solar radiation in the form of solar thermal energy is an alternative source of drying

especially to dry fruits, vegetables, agricultural grains and other kinds of material, such as

wood. This procedure is especially applicable in the so-called “sunny belt” world-wide, i.e. in

the regions where the intensity of solar radiation is high and sunshine duration is long. It is

estimated that in developing countries there exist significant post-harvest losses of

agricultural products, due to lack of other preservation means. Drying by solar energy is a

rather economical procedure for agricultural products, especially for medium to small

amounts of products. It is still used from domestic up to small commercial size drying of

crops, agricultural products and foodstuff, such as fruits, vegetables, aromatic herbs, wood,

etc. contributing thus significantly to the economy of small agricultural forms.

Solar drying can be used in fishing industry. The Indian coastline receives bountiful solar

energy except for the monsoon months; hence, solar drying is possible for most of the year.

Even The state government of Kerala has set up community-based fish drying units that are a

hybrid of FPCs and firewood. One of the potential application of solar drying lies in tea

industry.

More than 80% of the energy required is thermal in order to remove moisture from the tea

during withering and drying. So solar drying can provide a substitute to fossil fuel. Thus,

solar drying systems can play a considerable role in reducing the amounts of coal and

firewood used.

Solar drying of agricultural products is an important area of application of solar energy.

There can be large scale applications of solar dryers in various types of industries dealing

with marine products, grain , timber, vegetable, fruits , milk, textile, soap, powder,

electroplating etc. A few installations are under operation for drying onion flakes, tomatoes,

mushrooms, herbal products, wood, preheating of air etc.

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2.1.3 Solar Cooking

Solar cooking is the simplest, safest, most convenient way to cook food without consuming

fuels or heating up the kitchen. But it is a blessing for hundreds of millions of people around

the world who cook over fires fuelled by wood or dung, and who walk for miles to collect

wood or spend much of their meagre incomes on fuel. Solar cooking is more than a choice for

them. It also saves the rural households from indoor air pollution from solid fuel.

Moderate cooking temperatures in simple solar cookers help preserve nutrients. Smoke from

cooking fires is a major cause of global warming and dimming. Cooking fires are dangerous,

especially for children, and can readily get out of control causing damage to buildings,

gardens, etc. Solar cookers are fire-free. Biomass and petroleum fuelled cooking fires pollute

the air and contribute to global warming. Solar cookers are pollution-free, and when used in

large numbers, may help curb global warming.

There are four major types of solar cookers:

Solar box cookers

Dish cooker

Scheffler cooker

Solar steam cooker

Hundreds of variations on these basic types exist. Additionally, several large-scale solar

cooking systems have been developed to meet the needs of institutions worldwide. Most of

the solar cookers work on the simple principle: to convert sunlight to heat energy and

retained this heat energy for cooking food. Sunlight is the fuel for solar cooker. It doesn’t

work in cloudy days or night. Dark surfaces get very hot in sunlight, whereas light surfaces

don't. Food cooks best in dark, shallow, thin metal pots with dark, tight-fitting lids to hold in

heat and moisture. A transparent heat trap around the dark pot lets in sunlight, but keeps in

the heat.

2.1.4 Solar Space Heating

Solar energy can be used for various applications. One of these is space heating in winter

which can effectively reduce the cost of energy. It produces no emissions and is replenished

naturally. It will help to reduces greenhouse gases and saves the release of other emissions

7

that result from the burning of fossil fuels such as nitrogen oxides, sulphur dioxide or

mercury. It is ideal for space heating / warming of offices, hotels, industrial buildings,

residences etc.

Basically there are two types of solar space heating:

Active space heating

Passive space heating

In active space heating a solar collector absorbs the sun’s thermal energy to heat either air or

water, depending on the system, then a fan or pump moves the collected heat into the areas

needed, or heat is transferred to a storage system (usually liquid) for later use.

Passive solar technologies use sunlight without active mechanical systems (as contrasted

to active solar). Such technologies convert sunlight into usable heat (water, air, and thermal

mass), cause air-movement for ventilating, or future use, with little use of other energy

sources.

Today, solar heating is becoming more important than ever before. Natural gas and oil, which

are burned to heat our homes and water, are limited. As reserves of gas and oil shrink, these

fuels become more expensive. If more people began using solar heating systems, fossil fuels

such as oil and gas would become less expensive and last longer. Burning natural gas and oil

in our heating systems also causes air pollution. Even electric water and space heaters cause

air pollution indirectly, because coal and natural gas are burned to produce electricity in large

power plants. So if more people used solar energy to heat the air and water in their homes,

our environment would be cleaner.

2.1.5 Solar cooling

Generally, the sun tends to be viewed as a source of heat. However, there exist thermal

processes to produce coldness, in which water is cooled. These processes are generally

suitable for using heat provided by solar thermal collectors as the principle source of energy.

The solar applications as on today are available for cooling as well as air conditioning. By

cooling, we mean reducing the temperature for e.g. the temperature of a machine in industrial

processes. By air conditioning, mean conditioning of the temperature according to air

humidity or on account of climatic conditions.

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As paradoxical as it may seem, cooling using solar energy is feasible using solar thermal

energy. Solar chillers use thermal energy provided by the sun or other backup sources to

produce cold and/or dehumidification.

There are two main solar cooling processes:

Closed cycles, where thermally driven sorption chillers produce chilled water for use in space

conditioning equipment

Open cycles, also referred to as desiccant evaporative cooling systems (DEC), which

typically use water as the refrigerant and a desiccant as the sorbent for direct treatment of air

in a ventilation system.

Solar cooling has a number of advantages over alternative solutions, e.g.:

It can help reduce the electricity peak demand associated with conventional cooling, as

maximum solar radiation usually occurs when cooling is needed. Solar thermal cooling can

also operate in the evening by using thermal storage.

When summer is over, solar cooling systems can be used for heating purposes such as

domestic hot water preparation or space heating.

Examples:

100 TR System at Muni Sewa Ashram, near Vadodara.

212 TR Solar Cooling System at Civil Hospital, Thane.

90 TR Solar Cooling System at TVS Suzuki factory, Near Chennai.

Solar cooling has the potential to curb the ever-increasing demand for conventional energies

used for cooling purposes. Carbon dioxide from fossil fuel combustion alone creates roughly

four-fifths of the total man-made greenhouse gas emissions. Solar energy displaces carbon-

emitting sources while providing a non-polluting energy source for cooling. And by lowering

electricity demand at times of peak loads, it increases the stability and costs of the electricity

grids. Because of these strong benefits, the market penetration of solar cooling should be

supported by governments.

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2.1.7 Solar Distillation

About 70% of the planet is covered in water, yet of all of that, only around 2% is fresh water,

and of that 2%, about 1.6% is locked up in polar ice caps and glaciers. So of all of the earth’s

water, 98% is saltwater, 1.6% is polar ice caps and glaciers, and 0.4% is drinkable water from

underground wells or rivers and streams. And despite the amazing amount of technological

progress and advancement that the current world we live in has undergone, roughly 1 billion

people, or 14.7% of the earth’s population, still do not have access to clean, safe drinkable

water. Solar distillation scan be solution to provide safe drinking water to large population in

the countries where solar energy has easily accessible.

Solar distillation is a process that employs the use of solar radiation to purify brackish, saline

and polluted water. The Solar Distillation System combines water desalination

technology and solar power to make fresh water and render it as potable water for irrigation

or industrial use. Water purification plants can be constructed On-shore and off-shore.

Solar distillation produces clean water for consumption. Solar distillation units are easy to

construct, simple to operate and low maintenance. It produces 99.9% pure water for

consumption. These units do not have a carbon footprint as they are 100% clean and emit

absolutely no harmful toxins into the atmosphere. But this process is costly and weather

dependence. The system can only be used when there is a supply of thermal energy readily

available. The system will not be efficient in countries with little or no solar energy available.

The basic concept of using solar energy to obtain drinkable fresh water from salty, brackish

or contaminated water is quite simple. Water left in open container in backyard will

evaporate into the air. The purpose of solar still is to capture to this evaporated (or distilled)

water by condensing it into a cool surface using solar energy to accelerate the evaporation.

The rate of evaporation can be accelerated by increasing the water temperature and the area

of water contact with the air.

Basically there are four basic types of solar distillation system

Concentrating Collector Stills

Multiple-tray tilted (Cascade)

Basin Type

Tilted Wick

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Apart from drinking water application solar distillation has its application in agriculture

sector also because purified water is essential to irrigation to enable greater yield and quantity

of crops, maintenance of soil productivity, and protection of the environment.

Thus solar distillation can be a definite solution to the global water crisis. At present research

is being conducted to increase the efficiency of the present designs of the cascade-design and

basin-type solar stills.

2.2 Industrial Applications of Solar Heat

Industrial heating needs can be categorized into three main temperature ranges. All of them

can be achieved with solar. The lowest temperature range consists of everything below 80°C.

Solar collectors are capable of meeting these temperatures and are commercially available

today. The medium temperature category is between 80°C and 250°C. While the collectors

servicing this level of heat demand are relatively limited, they do exist and are on the verge of

emerging into competitive commercial production. The highest range includes everything

over 250°C and requires concentrated solar power (CSP) to achieve such temperatures.

Many industries already can take advantage of the commercially available low and mid-range

temperature solar thermal collectors. They are particularly suited to meet the heating needs of

the food, beverage, textiles, paper and pulp industries. Processes like sterilizing, pasteurizing,

drying, distillation and evaporation, washing and cleaning, and polymerization do not require

high temperatures and can easily benefit from flat plate and evacuated tube collectors. In the

food, wine and beverage, transport equipment, textile, machinery, and pulp and paper

industries, roughly 60 % of the heating requirements can be met by temperatures below

250°C. Despite tremendous opportunity, solar thermal heating for industrial processes has

been insignificant compared to the residential sector, and the few industrial applications that

do exist have been experimental.

Some of the industries in which concentrated solar thermal heat can be used are as follows:-

1. Food industry: The sector of food products and beverages sector has a large heat demand

in the temperature range up to 150°C. Common processes are pasteurization of liquid goods

at 65 to 100 °C, cooking at 100 °C in meat processing, blanching of vegetables or meat at 65

to 95 °C, drying and evaporation at 40 to 130 °C in fruit and vegetable processing or cleaning

of products and production facilities at 60 to 90 °C. Taking into account its big share of the

11

industrial heat demand at low temperatures, the food industry has a great potential for the use

of solar thermal energy.

2. Textile Industry: The heat demand of the textiles sector is limited to temperatures below

100 °C. Within the textile industry washing at 40 to 90 °C, drying and a large number of

finishing processes like dyeing and bleaching at 70 to 100 °C or resizing at 80 to 90 °C are

the main consumers of process heat. As a first guess, up to 25 to 50% of heat needed in the

textiles sector could be covered by solar thermal energy. This represents a large potential.

3. Pulp and paper Industry: Within the pulp and paper industry, about two-thirds of the

heat demand is needed at temperatures higher than 100 °C, which is unfavourable for solar

heating systems containing standard components, but could in principle be provided with

more advanced collector technologies. On the other hand, one-third is still consumed at

advantageous temperatures below 100 °C for process heat, hot water and space heating. The

preheating of boiler feed water represents a promising application for solar thermal energy in

this industry sector, as steam is needed for drying of paper products. Furthermore, the share

of energy cost is about 11 % of total manufacturing costs which indicates the high importance

of energy efficiency and the utilization of renewable energy in this sector.

4. Chemical Industry: The chemical industry is one of the most important sectors. The

processes within the sector are very demanding regarding energy and resources. Energy costs

are about 4 to 5 % of the total manufacturing costs. The heat demand plays a major role

within this energy demand, and although a large amount is needed at high temperatures, there

is still a considerable heat demand at low and medium temperature. Potential processes for

solar heat are especially bio-chemical processes with temperature levels about 37 °C as well

as preheating and polymerization processes.

5. Plastics Processing Industry: It is stated that about 40 % of the energy consumed in this

industry is used for process heat applications. Besides the supply of hot water and space

heating, drying of plastic pellets is a potential process for solar thermal energy. The pellets

are air-dried at temperatures from 50 to 150 °C to ensure quality during moulding.

6. Fabricated Metal Products. Here, the heat demand plays a major role for the overall

energy demand. Demand for hot water and space heating is quite high. The required heat is

needed at low temperatures, especially for coating processes. For example, surfaces are

12

etched in about 70 °C warm solutions and air-drying is an often used process that requires hot

air with about 120 °C.

7. Dairy Industry: In dairy industry there are many processes which require thermal heat.

Solar thermal systems can greatly contribute to energy savings during the production

processes in the dairy sector, which demand water temperatures of <80°C. These processes

are Bottle washing 60°C, Pasteurization 70°C, Yogurt maturation 40-45 °C, CIP (Cleaning-

in-Place) 70-80°C. The hot water produced by the solar collectors can also be used for pre-

heating the water entering the installation’s steam boiler.

8. Automobile Industry: There is huge demand of thermal heat for cleaning the auto-parts

and degreasing operations. Mahindra Vehicle in Chakan, Pune is using solar thermal heat for

its operation.

9. Service Industry: In service industries like hospitals, hotels, laundry, religious centres

the solar heat can be used for cooking, sterilisation, heating water, washing, drying and

pressing clothes, and space cooling using Vapour Absorption Refrigeration (VAR) systems

and air conditioning system.

13

Chapter 3: Concentrated Solar Technology

Solar thermal energy is an extremely convenient source of heating; and a technology that

does not rely on scarce, finite energy resources. Concentrated Solar Technology is a solar

thermal concentrating technology that converts solar energy to heat energy. CST a cost-

effective way to produce heat energy while reducing our dependence on foreign oil,

improving domestic energy-price stability, reducing carbon emissions, cleaning our air,

promoting economic growth, and creating jobs. CST at present is the need of the hour.

2.1 Solar Energy Resources

Solar radiation, often called the solar resource, is a general term for the electromagnetic

radiation emitted by the sun. Solar radiation reaches the Earth's upper Earth's atmosphere

with the power of 1366 watts per square meter (W/m2).

Sunlight passes through the atmosphere; some of it is absorbed (16%), scattered (6%), and

reflected (28%) by air molecules, water vapor, clouds, dust, pollutants, forest fires,

volcanoes. This is called diffuse solar radiation. The solar radiation that reaches the Earth's

surface (47%) without being diffused is called direct beam solar radiation. The sum of the

diffuse and direct solar radiation is called global solar radiation. Atmospheric conditions can

reduce direct beam radiation by 10% on clear, dry days and by 100% during thick, cloudy

days.

Solar radiation can be captured and turned into useful forms of energy, such as heat and

electricity, using a variety of technologies. However, the technical feasibility and economical

operation of these technologies at a specific location depends on the available solar resource.

The atmosphere affects the amount of solar radiation received.

2.2 Basic Principles

Earth receives sunlight at every location on at least part of the year. The amount of solar

radiation that reaches any one spot on the Earth's surface depends upon:

Geographic location

Time of day

Season

Local landscape

14

Local weather.

Because the Earth is round, the sun strikes the surface at different angles, ranging from 0°

(just above the horizon) to 90° (directly overhead). When the sun's rays are vertical, the

Earth's surface gets all the energy possible. The more slanted the sun's rays are, the longer

they travel through the atmosphere, becoming more scattered and diffuse. Since the Earth is

round, the surface nearer its poles is angled away from the sun and receives much less solar

energy than the surface nearer the equator the polar regions never get a high sun, and because

of the tilted axis of rotation, these areas receive no sun at all during part of the year.

Concentrated solar technology can use only the direct solar radiation for converting the

sunlight into some useful energy.

Concentrating solar technologies (CSTs) use mirrors to reflect and concentrate sunlight onto

receivers that collect solar energy and convert it to heat. Concentrating solar technology

offers a utility-scale, firm, dispatch able renewable energy option that can help meet our

nation's energy demand.

3.3 Types of Technology

There are four basic types of concentrated solar technology:-

1. Parabolic Trough

Out of the four CST technologies, the parabolic trough system (PTC) is the most

predominant and the most commercially mature CST system a concentration ratio of

around 100x. The parabolic trough uses parabolic or U-shaped concentrators to focus

sunlight along the focal lines of the collectors where the receiver tube is positioned, and

only fluid (heat-transfer fluid or water/steam) flows through the receiver tube. Solar

radiation heats up a heat-transfer fluid which then carries the collected thermal energy to

generate steam for using the heat through a heat exchanger into various applications.

The troughs track the sun over the course of the day along the central axis as the sun

travels from East to West. A 50 MW power plant based on parabolic trough technology is

under construction at Jaisalmer in the state of Rajasthan. Initial cost for trough technology

is higher than those for power towers and dish/engine systems due in large part to the

lower solar concentration and hence lower temperatures and efficiency.

15

Figure 2: Parabolic trough

2. Solar Parabolic Dish

The solar concentrator, or dish, gathers the solar energy coming directly from the sun.

The resulting beam of concentrated sunlight is reflected onto a thermal receiver that

collects the solar heat. The dish is mounted on a structure that tracks the sun continuously

throughout the day to reflect the highest percentage of sunlight possible onto the thermal

receiver.

The solar dish is a parabolic reflector that can turn on two axes to track the sun light. It

reflects the direct light onto a thermal receiver positioned at the focal point of the mirror.

Temperatures can rise up to 1000°C with concentration ratio up to 1000x. In connection

with a Stirling engine, these systems could be used stand-alone. Dish systems consist of a

parabolic dish point-focus concentrator similar to that of a satellite dish, a thermal

receiver, and heat receiver situated at the focal point of the concentrator. It is most widely

used technology in India for Concentrated thermal heat applications. Shirdi Sai temple is

using this technology for preparing meal for the 20000 devotees daily on average basis.

Figure 3: Parabolic dish

16

3. Solar Tower

Solar towers generate steam from sunlight by focusing concentrated solar radiation on a

tower-mounted heat exchanger (receiver). The system uses hundreds to thousands of sun-

tracking mirrors called heliostats to reflect the incident sunlight onto the receiver. As with

the other concentrating devices, the reflectors track the angle of the sun and positions

themselves automatically (dual axis tracking required). Temperatures can reach up to

1,300°C, which is much higher than in the other configurations. Thus due to having

temperature range more than 1000°C it is mostly used in power generation rather than

heat applications. The PS10 Solar power plant is the world's first commercial

concentrating solar power tower operating near Seville, in Andalusia, Spain.

Figure 4: Solar tower

4. Linear Fresnel Reflector

A second linear concentrator technology is the linear Fresnel reflector system. Flat or

slightly curved mirrors mounted on trackers on the ground are configured to reflect

sunlight onto a receiver tube fixed in space above the mirrors. A small parabolic mirror is

sometimes added atop the receiver to further focus the sunlight.

In this latest technology, reflector stripes are tilted in a way that is similar to a Fresnel

lens such that all incoming beams are reflected into collector that is situated around 3m

above the mirrors. The idea here is similar to the parabolic trough, except that it does not

require a huge parabolic shaped mirror, which is expensive to manufacture. Instead, the

reflector stripes can be flat. Clique Solar developed the ARUN dish which is based on this

17

technology. Turbo Energy Limited (TEL), Paiyanoor in Tamilnadu is using this

technology for cooling purposes.

Figure 5: Linear Frensel Reflector

18

3.4 Design Parameters

India is full of solar energy. A huge amount of potential exists for the use of solar thermal

concentrators to meet the heat application requirements in India. But large scale use of

concentrated solar energy for various thermal heat applications such as cooling, cooking etc

has not been reported. The important reason seems to be that the implementation of such

technologies for these applications poses many challenges. Such systems need to function as

per the inflexible process requirements of the industry in spite of variability of solar radiation

over the days and seasons. Also, the system needs to be reliable within acceptable range.

Further, the designer is expected to design a system with a minimum cost. In order to

overcome these hurdles, it is necessary to develop a design methodology and general

integration approach that can be used for optimally sizing the solar concentrators for various

process heat applications in field.

The solar industrial process heat system needs to be designed properly, considering the

random nature of the solar radiation as well as load characteristics.

The key points while designing the system are listed below:

1. Solar Radiation Data

The output of any solar thermal system is dependent on the solar radiation at the place

which has both daily and seasonal variations. Therefore solar radiation data in the

form of daily solar radiation (kWh/day), hourly data of beam normal radiation (kW/

m2) may be used for the prediction of the solar system output and designing the

system.

2. Location of Installation

The selection of the actual place of installation of the concentrator is also important

so as to minimize the fractional shading of collector (trees/buildings in the

surroundings) throughout the year. If number of collectors is more than one, then

arrangement can be made to minimize piping involved and to minimize shading of

the collectors.

3. Storage

Storage is used to partially/fully store the heat supplied by solar collector. It also acts

as a buffer which absorbs the output variations due to short time fluctuations in the

19

solar radiation. Storage of the energy is very useful as it allows system to deliver the

energy as per the load requirement.

4. Heat Transfer Medium

Steam: Flow rate should be adjusted such that flow is either in steam phase (steam

content > 90 %) or predominantly in liquid phase (steam content < 40 %).

Otherwise entire piping has to be designed for two phase flow.

Pressurized water: Optimum flow rate to avoid steam formation and minimize

pressure drop in the line, quality of water must be ensured to avoid scaling. Flow

rate should be maintained to avoid sudden steam formation.

Oil: Properties of the heat transfer oil must be ensured so that it is suitable for the

temperature range of the application. Operating temperature range must lie at least

50 °C below the boiling temperature of the oil.

5. Solar Concentrator

Solar concentrator must be selected carefully so that it is able to supply the load of

desired quality. Collector optical efficiency and overall heat loss coefficient are

generally considered as the important characteristic parameters of the concentrator.

(Source: Energtica India Nov/ Dec 2011)

20

Chapter 4: Heat and Its Measurement

Basically the heat is a form of energy and can change the matter it touches. It can heat it up-

which starts molecules moving or it can cause chemical reactions like burning to occur. The

transfer of heat can occur three ways: conduction, convection and radiation. Heat describes

the process of transfer of energy. The SI unit of heat is the joule. When gained or lost by an

object, there will be corresponding energy changes within that object. A change in

temperature is associated with transfer of heat. And with change in temperature of object its

physical state also changes. So when heat is transferred to water continuously then after a

particular temperature at corresponding pressure it will convert water into steam. For

example at 1 bar pressure water will be converted into steam at 100°C.

4.1 Basic terms

1. Heat Capacity - Heat capacity is the measurable physical quantity that specifies the

amount of heat required to change the temperature of an object or body by a given amount.

The SI unit of heat capacity is joule per Kelvin, J/K.

2. Specific Heat Capacity - The specific heat capacity refers to the amount of heat required

to cause a unit of mass to change its temperature by 1°C. Different materials would warm up

at different rates because each material has its own specific heat capacity. For example it

would take about twice as much heat to increase the temperature of a sample of aluminium a

given amount compared to the same temperature change of the same amount of iron. This is

because the specific heat capacity of aluminium (0.904 J/g/°C) is nearly twice the value of

iron (0.449 J/g/°C). The specific heat capacity of water is 4.184 J/g/°C or 1 calorie/g/°C at 1

bar.

3. Latent heat – It can be defined as the quantity of heat absorbed or released by a substance

undergoing a change of state, such as ice changing to liquid water or liquid water changing to

ice, at constant temperature and pressure. It is generally measured in kJ/kg or J/g.

4. Latent heat of Vaporization – It is the energy required to transform a given quantity of a

substance from a liquid into gas. The specific latent heat of vaporization is the amount of

heat required to convert unit mass of a liquid into the vapor without a change in temperature.

The latent heat of vaporization of water is 2257 KJ/Kg or 540 Kcal/Kg at 1 bar.

21

Figure 6: Phase change

5. Saturated steam - Saturated steam is steam that is in equilibrium with heated water at the

same pressure, i.e., it has not been heated past the boiling point for that pressure. If saturated

steam (a mixture of both gas and saturated vapor) is heated at constant pressure, its

temperature will also remain constant as the vapor quality (dryness, or percent saturated

vapor) increases towards 100%, and becomes dry (i.e., no saturated liquid) saturated steam.

6. Superheated steam - Superheated steam is steam at a temperature that is higher than its

vaporization (boiling) point at the absolute pressure where the temperature measurement is

taken. On Continuing heating of dry saturated steam it will transform into super-heated

steam. The steam is then described as superheated by the number of degrees it has been

heated above saturation temperature.

Figure 7: Vapour dome

7. Global solar irradiance - Global solar irradiance is a measure of the rate of total incoming

solar energy (both direct and diffuse) on a horizontal plane at the Earth's surface. A

pyranometer sensor can be used to measure this quantity with limited accuracy. The most

accurate measurements are obtained by summing the diffuse and horizontal component of the

direct irradiance.

22

8. Direct Normal Irradiance - Direct Normal Irradiance (DNI) is the amount of solar

radiation received per unit area by a surface that is always held perpendicular (or normal) to

the rays that come in a straight line from the direction of the sun at its current position in the

sky.

9. Diffuse solar irradiance - Diffuse solar irradiance is a measure of the rate of incoming

solar energy on a horizontal plane at the Earth's surface resulting from scattering of the Sun's

beam due to atmospheric constituents. Diffuse solar irradiance is measured by a pyranometer,

with its glass dome shaded from the Sun's beam. As diffuse solar irradiance is a component

of global solar irradiance, diffuse solar irradiance should be less than or equal to global

irradiance measured at the same time. Global and diffuse irradiance will be equal when the

contribution from direct solar irradiance is zero, that is, when the Sun is obscured by thick

cloud, or the sun is below the horizon.

10. Insolation - Insolation is a measure of solar radiation energy received on a given surface

area and recorded during a given time.

11. Aperture Area - It is the area through which solar energy enters the collector or

the aperture area of a solar collector is the area of the opening into which insolation passes.

This is the area one would obtain by direct measurement and does not include any area

reduction due to angle of incidence effects or shadowing. After passing through the aperture,

that insolation may be concentrated or absorbed as is the case for the flat-plate collector.

Figure 8 : Diffuse and Direct Solar Radiation

23

4.2 Measurement of heat for generating steam

Total Heat of Evaporation = Heat to change the temperature of the water + latent heat of

vaporization + required degree of superheat of steam in the process (at constant pressure)

Step 1 - Calculating the amount of heat required to increase the temperature of water

from ambient or initial level to saturation or final temperature.

We can calculate the required amount of heat with the help of following relation.

Q = M×C×ΔT

Where

Q is the quantity of heat transferred to or from the object

M is the mass of water

C is the specific heat capacity of the material water

And ΔT is the resulting temperature change of water.

Example 4.2.1 - What quantity of heat is required to raise the temperature of 1 kg of water

from 15°C to 85°C at atmospheric pressure?

In this problem, we know the following:

The specific heat capacity of water (c) is 4.18 KJ/Kg/°C.

m=1 Kg, Tinitial = 15°C, Tfinal = 85°C

We wish to determine the value of Q - the quantity of heat. To do so, we would use the

equation Q = m×C×ΔT.

The m and the C are known; the ΔT can be determined from the initial and final temperature.

ΔT = Tfinal - Tinitial = 85°C - 15°C = 70°C

With three of the four quantities of the relevant equation known, we can substitute and solve

for Q.

Q = m×C×ΔT = (1 Kg) × (4.18 KJ/Kg/°C) × (70°C)

Q = 292.6 KJ

24

Step 2 - To calculate latent heat of vaporization

The latent heat of vaporization of water is 540 Cal/gram or 2257 J/g at 1 bar. This value will

be different at different pressure. So to calculate total latent heat we have to multiply this

value with the mass of water which we want to convert into steam.

Example 4.2.2 - A beaker of water is heated to boiling. The water has a mass of 400 grams.

How much energy will be needed to boil it?

Q = m×Lv; Where m= mass; Lv = Latent heat of vaporization

m = 400 gram;

Lv = 540 cal/gram

Q = (400 g) × (540 cal/g) = 216,000 calories

Step 3 – To calculate heat required to superheat the steam

For this we will apply the same relation i.e. Q = M×C×ΔT.

Where

Q is amount of heat

M is mass of steam

C is specific heat capacity of steam at particular pressure

And ΔT is temperature difference or degree of superheat

Figure 9: Latent heat of vaporization

25

Example 4.2.3 -The Poona hospital needs 400 kg steam per hour between 9:00 am to 5:00

pm at 10 bar and at 180°C. The feed water temperature is 30°C. Calculate the amount of total

heat.

Solution – First we have to find out the saturation temperature of water at 10 bars from steam

table. The saturation temperature at 10 bars is 179.88°C or approximately 180°C.

Here M=400 Kg/hr.; C=4.18 KJ/Kg/°C or 1 Kcal Kg/°C; ΔT= (180-30) °C= 150°C

Step 1 – To Calculate amount of heat required to raise the temperature of water from 30°C to

180°C. Applying the relation (Q= M×C×ΔT)

Q 1= M×C×ΔT

Q1=400×1×150

Q1=60000Kcal/hr.

Step 2 – To calculate total latent heat

At 10 bar latent heat of vaporization is 480 Kcal/Kg (from steam table)

Q2= M×Lv = 400 Kg/hr.× 480 Kcal/Kg = 192000 Kcal/hr.

There is no requirement of superheat because steam is required at 180°C. So total heat

required is sum of Q1 and Q2.

Q= Q1+ Q2= 60000+192000= 252000Kcal/hr.

Now system will operate for 8 hours per day so heat required per day will be

=252000×8=2016000 Kcal/day

Thus the total heat requirement for producing 400 kg steam per hour will be 252000 Kcal.

In India, concentrating solar devices producing higher temperatures (80°C to 250 °c) have

been installed successfully. The majority of solar thermal installations on the ground use

parabolic dish collectors. Two technologies are prevalent for parabolic dish collectors:–

Scheffler dish technology

ARUN dish technology

Scheffler dishes have been traditionally installed for cooking applications at religious places,

whereas the ARUN dish was developed with a focus on IPH and comfort cooling

applications.

26

4.3 ARUN Dish

Clique Solar has developed patented ARUN dish for industrial process heating and comfort

cooling applications. Arun dish is a Fresnel paraboloid solar concentrator with point focus

and equipped with two axis automatic tracking system. The innovative design of Arun dish

ensures highest thermal energy output per m2 of collector area compared to any other solar

concentrator in India. The simplicity of operation coupled with the highest standards of safety

ensures minimum maintenance over an extended period of time. A unit of ARUN-160 dish

concentrator having 169 m2 of aperture area was developed and installed at Mahanand Dairy

at Latur in Maharashtra for pasteurization of about 20,000 to 25,000 litres of milk under

MNRE sponsored R&D and has been working satisfactorily since 2006. The ARUN dishes

can be used for steam application, hot water application, thermic oil heating, hot air

generation, desalination, comfort cooling, mass cooking application, effluent evaporation etc.

The dishes are now being installed at various places for different applications in the country.

Heat Delivery by Arun Dish

The heat delivery with one Arun dish can be calculated by multiplying aperture area of Arun

dish and the sun radiation it receives at particular place i.e.

Heat output = aperture area × Direct solar radiation

Example 3.3.1 -: Pune region receives 5KWh/m2/day direct solar radiations yearly and Arun

160 is having aperture area of 169 m2.

Then Heat output with one Arun 160 dish in Pune area will be = 169 m2× 5 KWh/m

2/day

= 169×5×3600 KJ/day

= 726708.1 Kcal/day.

If we consider the efficiency to be 65% then heat output will be = 726708.1 × 0.65 =

472366.765 Kcal/day. And Poona hospital requires 2016000 Kcal heat per day.

So number of Arun dish required = 2016000 /472366.765 = 4.26. It means approximately

minimum 4 dishes are required to fulfil the need of hospital for heating applications. Arun

dish is also available in size of 104 m2 aperture area.

27

Technical Specification

Parameters ARUN® 100 ARUN® 160

Aperture area 104 m² 169 m2

Foot‐print required 3m x 3m

Thermal mediums Hot water, steam or thermic fluid

Operating wind

speed

10 m/s or 36 km/hr.

Survival wind speed 47 m/s or 170 km/hr.

Weight Moving weight : 09 tons, total : 12

tons

Moving : 12 tons, total : 18 tons

Height 11.5 meter from top to bottom. 18 meter from top to bottom

Tracking energy 0.5 kWhe/day

Control system Micro controller or PLC based (as per client requirement)

Tracking system Two axis automatic tracking (NO manual intervention required)

Reflectors Solar grade flat float glass mirrors

Table 1: Technical Specification of Arun dishes

Figure 10: Arun Dish

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4.4 Scheffler Dish

It is a parabolic reflector which is set up to harness solar energy using low cost set up which

can be used in rural areas in India. A concentrating primary reflector tracks the movement of

the sun, focusing sunlight on a fixed place. The focused light heat a very large pot, which can

be used for heating, steam generation, cooking, baking breads, water heating. The Scheffler

reflector can be used for the supply of hot water for domestic purposes. These systems can

have one water storage tank which performs dual function of absorbing solar radiation and

preserving heat of water. This devise is developed by German Scientist Wolfgang Scheffler.

The axis of daily rotation is located exactly in north-south-direction, parallel to earth axis and

runs through the centre of gravity of the reflector. The focus is located on the axis of rotation

to prevent it from moving when the reflector rotates. There are various sizes of reflectors

such as 7.5 m2, 8.5 m

2, 9.5 m

2, 11 m

2 and 16 m

2.

4.4.1 Heat delivery of 16 m2 Scheffler dish in Pune

First step will be to calculate the collector area of 16 m2 Scheffler dish.

Aperture area is given by

Aperture area = 16 cos (43.23° + δ/2) where δ is seasonal angle deviation of sun.

Taking δ as 3°

We have aperture area = 16 × cos (43.23 + 1.5°) = 11.732 m2.

Then Heat output with one Scheffler dish in Pune area will be = 11.732 m2× 5 KWh/m

2/day

= 11.732×5×3600 KJ/day

= 50448.1605351Kcal/day.

So number of Scheffler dish required = 2016000 /50448.1605351= 39.96. It means

approximately 40 Scheffler dishes are required to fulfil the need of hospital for heating

applications.

29

Figure 11: Scheffler dish

So to design the size of solar system we require following input from the customer

Amount of Steam

Temperature Of Steam or Hot Water

Temperature of water at inlet

Pressure of Steam or Hot water

After obtaining these data we can easily make the calculations for the required heat and then

corresponding number of dishes for fulfilling these requirements

4.5 Indian Boiler Regulations

According to Indian boiler Regulation 1950 “Boiler” means any closed vessel exceeding

22.75 litres (five gallons) in capacity which is used expressly for generating steam under

pressure and includes any mounting or other fitting attached to such vessel, which is wholly

or partly under pressure when steam is shut off.

These Regulations generally apply to:-

all boilers, including those working on the principles of natural circulation,

forced circulation and forced flow with no fixed steam water line, and

To steam pipes

So all the solar systems which have boiler capacity more than 22.75 litres, they will have to

follow the norms of Indian Boiler Regulation 1950. The norms are available on

http://dipp.nic.in/boiler_rules_updated/contents1.html

30

Chapter 5: Financial Viability

Solar system draws energy from a free power source and requires very little maintenance.

The majority of the lifetime cost, therefore, is made up of equipment and installation costs.

The basic parameters that should be considered while evaluating the investment returns in

any solar energy system are as follows:

Cost of the solar energy system

Subsidies

Financing options

Value of energy generated

Non-financial factors that influence the economics.

Other than the standard investment rate of return, net present value and the payback period

calculations that are mostly used in evaluating investment opportunities, some sector specific,

economic indicators must be considered. These are as follows:

Cost per Kcal of energy delivered over the lifetime

Energy per unit area occupied

Energy gain ratio

5.1 Calculations of Payback Period

To calculate the likely financial benefits or payback period of any solar system is not easy.

This varies according to the variation in performance that is obtained at different locations

and from different equipment, as well as the usage patterns of the end-user.

Following points are considered while calculating the payback period:-

Initial equipment and installation costs.

Maintenance cost

Life expectancy of the system and any likely repair costs.

Location in the country i.e. sunny days available in that location and availability of

solar radiation

Solar system efficiency

31

Type and calorific value of fuel, its price and how this is likely to change - if you are

using PNG then payback period will be less as compared to use coal as a fuel because

the price and calorific value of PNG is more than coal.

Government subsidy available.

Let’s take the example of solar air conditioning system in Turbo Energy Limited, Paiyanoor

in Tamilnadu.

The Initial cost of solar air conditioning system including VAM, pumps, pipes etc.

=Rs.75.50 lakhs.

Government subsidy = Rs. 10.50 lakhs

Net Cost = RS (75.5 – 10.5) = 65 lakhs

Cost of traditional electrical chillers = Rs. 11.00 lakhs

Extra cost for solar chillers = Rs. (65-54) = 54 lakhs

Number of Sunny days (approx.) = 300 days

Number of working days (approx.) = 270 days

Working Hours per day = 8 hours

Per day energy saving = 58.5 ×8 =468 KWhr

Energy saving per annum = 468 × 270 = 126360 KWhr

Cost of electricity per unit (2012) = Rs. 7.00

Saving in energy bill per year = 126360 × 7 = Rs 884520

*Simple Payback Period = Rs (5400000/884520) = Rs 6.10 years

(source : Turbo Energy Limited)

*This payback period doesn’t include accelerated depreciation benefit and fuel escalation

price.

5.2 Cost of Installation

5.2.1 ARUN® 160

The cost of installation of one ARUN® 160 is around 45 to 50 lakhs including civil

foundation and transportation cost. Government of India is also providing subsidy of Rs 10,

14,000 on each ARUN® 160 dish. The concentrating solar collector system, ARUN®160 is

designed for 30 years life under standard operating conditions and regular maintenance as per

the manufacturer’s instructions.

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5.2.2 ARUN® 100

The cost of installation of one ARUN® 100 is around 30 to 32 lakhs including civil

foundation and transportation cost. Government of India is also providing subsidy of Rs 6,

24,000 on each ARUN® 100 dish. It is also designed for 30 years under standard operating

system.

5.2.3 Thermax SolPac D160

This is a 16 m2

parabolic (Scheffler) dish manufactured by Thermax. The installation cost for

each dish varies from 3 lakhs to 3.5 lakhs. As the number of dishes increases the price of each

dish economize accordingly. Each dish requires at least 35 m2

shadow free space.

5.3 Comparison between Arun and Scheffler dish

The selection between ARUN and Scheffler can be made on considering following factors: -

1. Space – Arun require very less footprint area as compared to one Scheffler dish. For

ARUN® 160 only 3 × 3 m2 area while for Thermax SolPac D160 minimum 35 m2 is

required. But one thing should be kept in mind that although the footprint area for

ARUN dish is less but it needs more aerial space than Scheffler dish. So if there is

large space available then Scheffler dishes can be opted.

2. Cost – The cost of installation of Scheffler dish is much lower than the ARUN dish.

So if budget is less than Scheffler dish will be the optimum solution. But maintenance

cost of ARUN dish is lower and its life is also greater.

3. Requirement – If the requirement of hot water or steam is less than using Scheffler

dish will be optimum than ARUN dish. The minimum size of ARUN dish available in

the market is of 30 m2 whereas the Scheffler dish is also available in size of 7.5 m

2.

4. Thermal Output – ARUN dish delivers 2.5 to 4 times more heat per m2 as compared

to Scheffler dish.

5. Tracking System – ARUN dish has double axis automatic tracking system whereas

in Scheffler dish the tracking in east west direction is automatic but in north south

direction it has to be adjusted manually.

33

Chapter 6: Environment Benefits of Using Concentrated Solar System

6.1 Climate Change

The burning of fossil fuels for energy remains the world's No. 1 source of carbon dioxide

emissions. Solar steam generating system is sometimes described as a zero emissions or

emissions-free form of energy and it is true that greenhouse gas emissions from solar are

negligible. Many scientists now believe these emissions may be affecting our climate. CO2

can create a "greenhouse effect" in the atmosphere, causing global warming. This may lead to

an increase in hurricanes, flooding and other weather conditions that can result in injuries,

deaths and loss of property. No combustion takes place in concentrated solar system that is

why it is known as green technology.

6.2 Water

Creating energy is a water intensive process. The concentrated solar energy systems can

recycle the used water for producing steam which results in saving of water. These systems

also do not pollute the water.

6.3 Land

Concentrated solar system when placed on existing structured, such as the rooftop of a home

or office building, solar energy systems require negligible amount of land space which is an

excellent way of utilizing waste or unused land. Also the use of fossil fuel leads to land

degradation which can be reduced by using solar system.

6.4 Solid Waste Generation

Solar-thermal technologies do not produce solid waste while converting water into steam

which helps to keep our environment clean and safe.

6.5 Unlimited Resource

Coal, natural gas and oil are limited resources, which we are using up at an incredible rate.

Developing countries are now adding to the demand for these fuels. Also, oil is used in many

ways other than producing energy, such as in the manufacturing of plastic products, thus

using oil reserves even faster. Solar energy from the sun is unlimited.

34

6.6 Solar Reduces Air Pollution

When fossil fuels are burned, particulate matter is released into the air, regardless of efforts to

reduce these emissions. The result can affect the environment in the form of smog, and in

certain cities, this can pose serious health problems for residents. Also, carbon monoxide is

created when fuel combustion is incomplete. This gas is a health hazard, even in low doses.

Energy produced by solar systems does not contribute to air pollution

6.7 Clean Energy

Concentrated solar system creates clean, renewable energy that will sustain and support the

health of future generations. It is a distributed generation ("DG") energy source that can

reduce the national security concerns about energy security.

6.8 Solar air conditioning units offer environmental benefits including lower grid demand

and load shifting during peak usage, reduced electricity costs, fewer power outages, off-the-

grid capabilities and reduced greenhouse gas emissions.

6.9 Solar cooking can be a more healthy way of preparing our foods for consumption as

opposed to gas, smoky open fire, microwave etc. because it uses the natural power of the

sun's energy and best of all, it preserves more of the natural nutrients of the foods by cooking

at slower and lower temperatures.

6.10 Saving eco-systems and livelihoods

Concentrated solar system solar discourages the use and mining of raw materials which

results in the saving of forests and eco-systems that is continuously depleting with most fossil

fuel operations.

35

Chapter 7: Barriers

Despite the large potential for solar energy to meet industrial thermal demand, there are

several barriers to large scale implementation. The most noteworthy barriers are cost,

variability of output, energy storage and process integration.

7.1 Cost

The economic viability of solar thermal energy depends largely on two factors: the initial cost

of the installation and the price of alternatives. High upfront costs often prevent companies

from investing in new technology, like solar thermal, even if the overall lifetime cost would

be lower. However, while the cost of solar technologies is decreasing, the financial

investment in solar remains more stable than many of the markets for fossil fuels. Thus, the

largest driver of a collector’s cost effectiveness is often the price of alternatives, like coal, oil

and natural gas, not the cost of the collector itself. The more expensive fossil fuels become,

the easier it is to justify an investment in solar thermal energy. Nevertheless, if the price of

solar thermal were to drop, it would certainly enhance its economic viability. With the

volatility of fuel prices, some manufacturers opt for the fixed upfront cost with a predictable

payback period. In addition to the potential for a lower overall cost, there exists a benefit

from having a predictable cost structure which is insulated from fuel market volatility.

Furthermore, solar thermal collectors can be made even more cost effective when tailored to

the specific process heating needs of the plant on the factory level, large-scale applications

can benefit from economies of scale and lowered investment costs, increasing its economic

viability.

7.2 Variability

Solar energy, unlike wind energy, can be predicted to a high degree of confidence. Its

availability, however, presents challenges for industries that require “24/7” demand. The

reliability of the heating supply is of paramount concern to many manufacturers for whom an

unanticipated disruption in production can be economically devastating. Solar thermal energy

is reliable but not always available. Therefore, industries which either do not require constant

production, or for whom the sunlight availability can be aligned with heating requirements,

may be more confident about integrating solar thermal energy into their production. The

variability of sunlight can also be mitigated by conducting statistical analysis of heating

36

requirements and the regional insolation. This can be conducted as part of a procedure known

as process integration.

7.3 Process Integration

Process integration, also known as “pinch analysis,” is a field of engineering which seeks to

optimize operational energy efficiency, or in other words, to reliably produce a product with

the minimum energy inputs necessary. The variability of energy supply must be quantified

based on daily solar radiation, ambient temperature profiles, and available storage

opportunities, so that the solar collectors can be optimized to reduce economic inefficiencies.

Variable energy, like solar and wind, presents a particular challenge for process integration

because the supply of energy is non-continuous. Therefore, the nature of solar thermal energy

supply must be addressed or it can become unaffordable in some cases.

If solar collectors supply all of the energy, the manufacturer must either align production with

the energy supplied, or store the energy for later use. However, even if sunlight is not

available to meet all of a factory’s thermal energy needs, solar thermal can still play a role by

supplying a portion of the total energy required. Under such hybrid systems, solar collectors

can provide a baseline energy supply whenever it is available and the remainder can be

fulfilled by a complementary fuel source. The commercially available low temperature

collectors are especially effective in this strategy and are often used for pre-heating

purposes.

7.4 Energy Storage Options

Large scale thermal energy storage is a nascent market but it can compensate for the inherent

variability of sunlight. For low and medium temperatures, this can usually be performed by

storing the heat in a transfer fluid like hot water or oil. Sometimes pressurized steam is used.

For higher temperatures, this becomes more difficult, and costly, and requires an alternative

heat transfer fluid and storage material.

The most common heat transfer fluid for CSP is molten nitrate salt, which is thermally

stable within a temperature range of 220° C to 565°C, below which the salt freezes.32 The

molten-salt system is currently the only practical thermal energy system with hours-long

storage potential, and has proven reliable at commercial scales.

37

Chapter 8: Conclusion

There are no doubts that solar energy will make an essential contribution to a future,

sustainable energy supply. The main use of solar radiation will be to produce thermal energy

in a wide range of temperatures. The basic technology for these applications has been

developed in recent years and is increasingly used; thermal energy costs, however, are still

higher than for competing conventional technologies.

In today’s world we are now faced with energy uncertainty. Whether it be the threat of global

warming, or our energy independence from foreign nations the India is faced with many

questions to answer on how we will produce energy in the future. Solar energy seems to be

the wave of the future. The adoption of solar thermal technology is very low in the country,

in spite of generous capital subsidy offered by MNRE. The use of solar thermal technology

can substantially reduce fossil fuel consumption in the domestic and industrial sectors, which

would result in a considerable reduction in annual CO2 emissions. There are only a limited

number of solar thermal installations in India in spite of simple and inexpensive

manufacturing and short payback periods.

Most of the data available at present is based on experience of a few projects only. Hence,

there is a severe shortage of statistics on the techno-economics of solar thermal applications.

Distribution of data specific to the technology, workings and economics of solar thermal

systems would provide momentum in increasing the adoption of these technologies.

To overcome the initial cost barrier, which is typical for most innovations, political support in

form of legislation and market introduction incentives will still be required. The extent and

duration of these subsidies varies for the different solar thermal technologies and depends

greatly on the cost development of the fuels which need to be replaced. While small domestic

solar thermal systems are more or less competitive at present oil/gas prices, large systems

with seasonal heat storage will need at least another decade to reach this target. In some

applications, industrial solar hot water systems may already be a viable option, whereas

systems for process heat at higher temperatures still require significant moral and financial

support. However, this technology is still a long way from commercialisation, even though

promising technologies have been developed in recent years.

.

38

All solar thermal technologies have significant potential for cost reduction. Substantial

research and development efforts will be required over the next coming years in the various

applications. Furthermore, the problem of intermittent and seasonal availability of solar heat

will have to be addressed. This requires the development of new storage technologies with

greatly improved performance.

In addition to environmental and long-term financial advantages, solar thermal technologies

will provide a number of environmental benefits, which are more difficult to quantify. This

includes a reduction of the dependency from imported fossil fuels as well as a growth in local

employment. The India will always benefit from solar thermal technologies

39

FOUR SUCCESS STORIES OF CST INSTALLATIONS IN INDIA

1. SHIRDI SOLAR STEAM COOKING SYSTEM

About Shirdi

Shirdi, a small town in Ahmednagar Dist. of Maharashtra boasts of owning this famous

temple where almost 30000 devotees visit daily. The temple has one of the largest kitchens in

India and the largest cooking systems in the world, which caters to the food needs of the

devotees at subsidized rates. Thousands of devotees partake of food at a nominal rate of

Rs.4/- per meal for adults and Rs.2/- per meal for children.

Besides a blessing to the devotees, the temple also practices its environmental right by the use

of solar cooking systems. It is further looking into innovative ways of reducing its overhead

costs by installing solar water heaters in its dharmashalas/dormitories, wherein the devotees

take shelter. They have also switched over to solar street lighting in their pumping complex,

thereby, drastically reducing the fuel and electricity costs incurred by the temple. Needless to

say, there was no other ideal place than this sacred place (temple) for solar energy to take its

initial flight in Maharashtra.

Although solar energy and related systems is the talk of town today, the management of

Shirdi Sai Anshan deserve a pat on their back for their constructive decision to opt for solar

mass cooking system. This undoubtedly was the need of the hour as Shirdi Sai Temple

happens to be one of the famous temples in India, where multitudes of devotees come for

darshan. Offering Prasad to these visiting devotees required clean, hygienic and large cooking

system. Therefore, in 2009 Sai Sansthan installed solar cooking system. Besides two other

spiritual centres in India, i.e. Tirupati Balaji, Andhra Pradesh and Brahma Kumaris, Mount

Abu, Shirdi Sai temple also followed suit to tread the revolutionary green path taken in the

way of installing solar steam cooking system.

Why Solar Energy

With the sky-rocketing fuel prices, and a fast exhausting commodity basket, there was no

better alternative than using the God given source of energy viz “Solar Energy.” Hence, the

first mass solar cooking system was installed in Shirdi in 2001, for preparing 7000 meals per

day with the financial aid from Indian government. Finding this to be user-friendly, a much

40

larger system with greater capacity was installed in the year 2009 in Shirdi to serve 20,000

devotees. The management of Shirdi is more than happy and satisfied with the operation of

the system, which saves on money and time.

Goals

Initially, steam generated by LPG fired boilers was the source of energy used for cooking at

the Sansthan. The Sansthan earmarked the following goals:

50% reduction of LPG gas consumption by use of solar energy

Use of clean and renewable solar energy for environmental protection, conservation

and rejuvenation.

Popularize and promote use of solar energy.

Technical Description of Solar System

Scheffler dishes are parabolic reflector set-up to harness the solar energy at low cost. These

dishes are very useful in rural areas. The heating equipment consists

of concentrating reflectors that move to track the movement of the sun, focusing sunlight on a

fixed place. The focused light heat the receiver pot, which can be used for heating, steam

generation, cooking and other applications.

The solar steam cooking system installed at Shirdi has 73 parabolic concentrators/dishes

(Scheffler dish) placed on the roof of Sai Prasadalaya Building No.2. The use of Scheffler

reflectors can result in effective water heating by using the non-uniform distribution of solar

radiation on the cylindrical absorber surface. In most of these systems the part of the

cylindrical absorber is thermally insulated in order to reduce storage tank thermal losses.

They reflect and concentrate the solar rays on the 40 receivers placed in focus. Water coming

from the steam headers placed above the header centres is received from bottom of the

receiver, gets heated up due to heat generated (about 550 °C) due to concentration of solar

rays on the receivers and gets pushed up via top pipe of receiver into the header. The

principle of anything that gets heated is pushed up is called thermosyphon principle. The

advantage of thermosyphon principle is that no pumping (thus no electricity) is needed to

create circulation since the heated water is pushed into the header and water from the same

headers come into the receivers for heating. The cycle continues till it reaches 100 °C and

gets converted into steam. The steam gets stored in the upper half empty portion of the header

41

pipe and pressure keeps on rising. The steam is then drawn / or sent to kitchen through

insulated pipe line. A timer mechanism powered by Solar cell (which converts sunlight into

electricity) gradually rotates the mirrors, so that they constantly face the sun as it moves

across the sky. The entire system is run by one operator.

All the 73 dishes rotate continuously along with the movement of the sun, always

concentrating the solar rays on the receivers. This movement of concentrators is called

tracking, which is continuous and is controlled by the fully automatic timer mechanism. Only

once during the day i.e. early morning the dishes are to be turned manually onto the initial

position, subsequently the automatic tracking takes over.

The specialty of this solar cooker invented by Wolfgang Scheffler is that it generates steam

unlike the earlier models where the cooking pot was placed at the focal point of the parabolic

mirror. This system is integrated with the existing boiler to ensure continued cooking even at

night and during rains or cloudy weather.

The solar cooking system is designed to generate over 3500 kg of steam a day at 180°C and 9

bars, which is sufficient to cook meals for around 20,000 devotees. The total cost of the

system is about 133 lakhs. Out of the total cost, the temple's share of expenditure was 71.67

lakhs and the Union Ministry of Non-conventional Energy Sources provided the 58.4 lakhs as

subsidy. The project has also availed 2.94 lakhs as subsidy of carbon credit from international

organizations. The maximum saving is around 263 kg/day (LPG) which adds up to 29

lakhs/annum and the payback period was 2 to 4 years with a life span of 25 years. It also

helps in pollution control and avoids emission of around 2000 metric tons of CO2 per year.

Figure 12: Solar system in Shirdi

42

DETAILS OF THE SYSTEM

S

No

Particular Remark (as of 2011)

1 Technology Scheffler Parabolic Dish

2 Total no of dishes 73

3 Collector area per dish 16 Sq. m

4 Total collector area 1168 Sq. m

5 Tracking System Single axis tracking

6 Steam generation Approx. 3500-5000 kg/day at 9 bar and 180-

190 °C temperature

7 Operational since August 2009

8 Purpose Mass Cooking

9 Baseline Fuel LPG

10 Total system Cost Rs 1.33 crores

11 Energy created by one dish during 8 hr

period

37840 kcal

12 Total energy created by all dishes per

day

27,62,320 kcal

13

Daily consumption of LPG Per/day 1700 kgs

14 Calorific Value of LPG 13500 kcal/kg

15 Total 229,50,000 kcal

16 Total savings of LPG per day in kgs 205

17 Rate of LPG Per Kg 45

18 Total Savings per day Rs. 9225

19 Yearly Savings ( 300days out of

365days)

27,67,500

20 Investment by Sansthan net of 50%

MNRE Subsidy

65,00,000

21 Payback Period 2.35 years

Table 2: Specifications of Shirdi solar system

43

Conclusion

India has large number of pilgrim centres which attracts visitors from across the globe all the

year round. These centres, with large community kitchens, cater to the visiting devotees

needs with a variety of food. To make this a success story, the government should further

subsidize and lower the cost of solar panels. The system installed at Shirdi is one such good

example of proper planning, as the solar system was deliberated at the design stage of the

temple’s new kitchen for pilgrims. Planning the system at the design/ construction stage has

helped the Sansthan to avoid pipeline exposure, giving the building a good aesthetic.

According to National Council of Applied Economic Research report around 230 million

devotees visit religious centres and the number is increasing every year; out of which major

pilgrim centres such as Tirupati, Vaishno Devi, Puri, Shirdi, Kedarnath, Naina Devi, Golden

Temple, Ajmer Dargah, Haridwar, and Mathura contribute for around 110 million devotees.

Shirdi is already using solar cooking system. If other centres also start using this system, it

will save approx. 1025000 kg of LPG fuel annually, which will help the nation save Rs

46125000 annually. It will also cut down CO2 emissions by 27000 kg annually, which will

have a positive impact on our environment.

Hence, the onus lies on the government to implement appropriate measures and promote the

use of CST system at religious centres, commercial and industrial sectors for a greener and

cleaner environment.

44

2. CSM HOSPITAL, THANE

Promoted by Thane Municipal Corporation (TMC) an Urban Local Body recognized for its

green energy initiatives at national level was duly awarded the “Green City Award,” by

MNRE for two consecutive years. Although it was hard for TMC to venture into an

altogether new technology initially, but with the ardent support and encouragement of green

enthusiasts, MNRE and Sharda Inventions Pvt. Ltd., a Nashik based manufacturer, selected

by MNRE, the project took off in a positive direction.

Solar Energy is the future energy. This was well recognized by Chhatrapati Shivaji Maharaj

Hospital at Thane in Maharashtra, which is today the proud owner of solar concentrating

systems and uses it for Cooling, Hot Water, Sterilization and Laundry applications.

Before the solar system, they were using electricity as energy source. Installation of solar

system helped them in reducing large amount of electricity bills and also increased their

independency from conventional energy source.

About the Hospital

The inception of Chhatrapati Shivaji Maharaj Hospital was in 1st October 1991. Indoor

admissions per year are on an average 20000. Total operations performed per year are 7500-

8000. All National Health Programs are implemented by this hospital. Hospital provides

preventive, promotive and curative services to the citizens of Thane Corporation as well as of

Thane District and surrounding areas.

The Energy Scenario of CSM Hospital in 2004 (Before Installing Solar Air Cooling)

It was conducted by Energetic Consulting Pvt. Ltd. in 2004

Thermal energy is used for steam generation and burning of hazardous waste

generated in hospital. Thermal energy bill is Rs. 34.0 Lacs per annum, which accounts

for 31% of the total energy bill.

Electrical energy is used for lighting, chilled water generation, for air handling units,

water pumping etc. Electrical energy bill is Rs. 75.51 Lacs per annum and accounts

for 69 % of the total energy bill.

45

2004 Thermal Energy Scenario

Cost of Energy Operations of Existing System

Table 3: Cost of existing energy system in CSM Thane

Reasons for Considering New System

The vapour compression system was installed in the year 1991; hence the system is

about 15-16 years old and inefficient too.

DG backup is not sufficient to operate electrical chillers in case of power failure.

High maintenance cost of the reciprocating machines, which are running at low

efficiency, lack of (proper) conditioned air for OPD section resulting in suffocation

and discomfort at OPD; and it also does not include additional load of conditioned

ventilation at OPD.

Fresh air is required to be added to the system as per ASHRE standards 62.1 for

indoor air quality management.

Hot water requirement for laundry consumption.

12 8

9

22

49 Press Machine

Dryer 1

Dryer 2

Washing Section

UTILITY EQUIPMENT CAPACITY

Boiler installed capacity (HSD Fuel) 500 kg/hr x 2 no

Air conditioning system installed capacity 90 TR x 2 nos.

Air conditioning system energy

consumption

10 Lacs kWh / annum

Cost of electrical energy for air

conditioning

Rs. 38 Lacs / annum

Cost of maintenance of AC system Rs. 13 Lacs per annum

Fuel consumption for boiler (HSD) 72 KL per annum

Cost of fuel for boiler Rs. 27 Lacs / annum

Cost of maintenance of boiler Rs. 4 Lacs per annum

Total cost of energy operations Rs. 82 Lacs / annum

46

Details of Solar Air Cooling (SAC) System in the Hospital

80 TR x 2 Nos. of Vapor Absorption Machines (VAM) is operating on 8 bar steam

generated by 184 nos. of solar parabola, each of 13.6 m2 area to generate chilled

water. This chilled water at 7°C is circulated through Air Handling Unit (AHUs) and

FCUs for providing air conditioning. During Cloudy days eco-friendly carbon neutral

agro residue-based briquette fired boilers, installed as a backup, generate the required

steam.

Liquid Desiccant System (LDS), technology developed by IIT Mumbai, is used for

dehumidification of air that is fed to the OPD section. This air enters the OPD section

at 26 °C and 15 °C dew point and is cooled using chilled water made out of SAC. All

put together, 2502.40 m2 of solar parabolic concentrator area is being used to provide

160 TR chilling and 52.5 TR conditioned ventilation.

The project is designed, developed, operated and maintained by M/s Sharda

Inventions Pvt Ltd, Nashik. It is aimed at reduction in Green House Gas (GHG)

emissions to 1200 CERs equivalent tons of carbon dioxide. The CDM benefits of the

project are availed and are included in the project cost. Similarly, the project is

eligible for solar concentrator subsidy available from MNRE as per the prevailing

norms.

Features of SAC system

• It is a novel concept using solar thermal energy for air conditioning contributing to

national cause.

• VAM COP is above 1.26

• No compressor is required. It is a most effective step towards energy conservation.

• Drastic reduction in expensive maintenance.

• No C.F.C. is produced. It is an effective step to protect ozone depletion with an eco-

friendly design.

CDM and MNRE subsidy benefits

• The project has renewable energy solutions that attract clean development mechanism

under Kyoto protocol for carbon emissions

• The extent of carbon credits is CER per annum equivalent to Rs. 6 Lacs per annum.

• MNRE subsidy for solar air conditioning system is estimated to be Rs. 124 Lacs.

47

Figure 13: Solar system in CSM Thane

CAPITAL STRUCTURE

Particulars Amount, Rs.

Lacs Solar Air Conditioner 231.91

LDS dehumidifier 45 Boiler 18

Cooling tower 4.5 Chilled water pump 2.55

Cooling water pump 3.5 Air blower 2.5

Subtotal 307.96 Low side modifications 62 PMC + CDM cost 30

Subtotal 92.0 GRAND TOTAL 399.96

(less) MNRE subsidy (-) 124 TOTAL CAPITAL OUTLAY 275.96 Courtesy: M/s Sharda Inventions Pvt. Ltd., Nashik

Table 4: Capital Structure of CSM Thane

Table 5: Payback period of solar system in CSM Thane

TOTAL CAPITAL OUTLAY FOR THE PROPOSAL AFTER

CONSIDERING CAPITAL SUBSIDY SHALL BE Rs. 275.96 Lacs

• Total cost reduction potential due to energy : Rs. 60 Lacs /annum

(expected as per present tariff )

• CDM revenue proposed by the bidder : Rs. 6 Lacs /annum

• Simple payback period based on the above = 275.96/66 = 4.18 years

48

Conclusion

In the present scenario, solar cooling is both possible and reliable. Using solar energy for

cooling purpose is a beneficial idea with good prospects for conventional air conditioning

systems. The replacement of compressor cooling systems by solar driven desiccant cooling

systems or a combination of both could make an important contribution to environmental

protection. The main argument for the applicability of solar energy is that cooling loads and

solar availability are approximately in phase.

A typical urban Indian hospital uses approximately 55% of energy for Heating Ventilation

and Air Conditioning (HVAC), 10% for lighting, 9% for operation of medical equipments

and the rest (approx. 26%) for laundry, kitchen, autoclave (sterilization), etc. The energy

requirement in hospitals for HVAC, laundry, cooking and sterilization (i.e. about 81% of the

total energy requirement) can be met through use of concentrating solar technologies (CSTs).

Suggest every hospital connects with CST, for a greener, cheaper alternative energy source

and save the environment.

49

3. Gajraj Dry cleaners, Ahmednagar

Gajraj Dry Cleaners

The unit is situated in Ahmednagar district of Maharashtra. Mr Suresh Chavan started this

laundry in 1971 with limited resources and manpower. Today they have 90 permanent

employees, 1 central unit for washing, drying, and pressing of clothes, 7

collection/distribution centres in the city of Ahmednagar and in nearby villages. They do

washing, drying and pressing of all kinds of clothes. They handle 3000 different types of

clothes a day. In view of reducing labour cost and improving quality output Gajraj dry

cleaners opted for modern machineries operating on steam.

Solar Laundry is the optimization of a Laundry, dry cleaning unit through the use of solar

steam generating systems. Large amount of steam required for industrial laundry can be

supplied by solar energy. Gajraj Drycleaners are using this solar energy for washing, drying

and pressing 3000 cloths every day.

Large scale wood, kerosene, diesel and coal were used to meet the energy needs, prior to

switch over. Very soon they realized that energy is the major cost factor, for a business that

requires a lot of steam for its operation. They identified and installed solar system, looking

into its long-term benefits, although the solar market was not much developed and there were

hardly any takers in the country. However, encouraged by the successful operation of certain

solar concentrating systems for other applications, which was profitable, they took the

conscious decision to solarize their business, appreciated and financially supported by

government for their green initiative. Today Gajraj Drycleaners happens to be one of the

largest solar laundries in India

Figure 14: Solar system in Gajraj Drycleaners

50

The Solar System in Gajraj Dry Cleaners

Gajraj Dry Cleaners require 1300 kg of dry saturated steam at pressure 7 bars and

temperature 170°C. To cater to their large demand of steam for laundry applications, they

already had a diesel fired boiler. With a view to maximize profitability by reducing labour

costs, they installed concentrated solar system based on Scheffler dish technology in 2006.

The solar steam generating system has 15 Scheffler dishes of 16 m2 each.

The dish concentrators concentrate solar heat at focal point with mirrors at its base. Heat

collected at the focal point is received by water which immediately converts into steam that

flows through header pipe for the central collection at collector vessel. The steam thus

collected is transported to drier through pipes for washing, drying and pressing clothes.

The focus is maintained by sun tracker. The receiver is a welded metal cavity with inlet and

outlet ports coated with black selective surface which collects the heat from the Sun and

transfers it to water flowing through it. The water converted into steam in the receiver flows

through the header tube made up of steel with designed diameter and insulation. The steam

collected in the header tube is then directed to laundry machineries with the help of insulated

steam piping.

The steam thus produced, augments the steam supply from existing boiler running on diesel

oil and then the system practically runs on 100% solar from morning 11 o‘clock to 4 o’clock

in the evening on a clear sunny day. The steam output is used for parallel applications of

cloth washing, drying and pressing. The system has been hooked up with their existing boiler.

It has been reported to be saving around 6500 litres of diesel per year and payback period is

less than 3 years after availing subsidy from MNRE and depreciation benefits.

During release of heat from steam to laundry applications it condenses into water which is

collected from drain pipes for reutilization through recirculation to produce the steam again.

The recirculation helps in water conservation.

Highlights

Simplified laundry operations

Saving 6500 liters of diesel per year.

Highly profitable with a whopping Rs. 3.5 lakhs saved per year

Controls pollution and avoids emission of around 17 metric tons of CO2 per year

51

Key Data of System

Particulars Remark

Technology Scheffler parabolic dish

Total collector area 240 m2

Collector area per dish 16 m2

Tracking system Single axis tracking

Steam generation Approx. 750-870 kg/day at 7 bars pressure

and 180°C-190°C temperature

Operational since 2009

Purpose Laundry

Baseline fuel HSD

Total system cost Rs 23 lakhs

Estimated fuel savings 6500 litres per annum

Estimated monetary savings Rs. 3 lakhs per annum

Payback period 2 years

Table 6: Technical specification of solar system in Gajraj drycleaners

Conclusion

Laundry industry requires a huge amount of steam, which solar flat plate collectors cannot

provide. To meet such higher temperatures up to 200°C, Scheffler technology is one of the

most reliable and proven systems available in the market with attractive payback period. The

manufacturers are continuously striving for better output by further upgrading system with

the advancement of technology. Undoubtedly, the laundry industry is gaining momentum

towards acceptance and use of green technologies. The initial investment is expensive, but a

large-scale unit can recover the amount invested in a comparatively short period.

Today the market of concentrated solar technology has already developed. With added

Incentives provided by government of India, it makes the solar laundry applications further

attractive commercially.

Today the management of Gajraj Drycleaners is happy with the benefits reaped by

Installing CST for solar laundry application.

52

4. ITC Maurya

Figure 15: Solar system in the roof of ITC Maurya

About ITC Maurya Hotel, New Delhi

ITC Maurya, a premier 5 star hotel in Delhi is named after the famous ‘Mauryan” dynasty

which gave Indian history its golden era, where art, culture and architecture flourished. This

luxury hotel in Delhi has 440 rooms, including 29 uniquely-designed suites, available in a

bouquet of room categories, from the Executive Club which pioneers a tradition in corporate

hospitality to the Towers’ eight luxurious floors of elegance and tranquillity. It combines the

best of opulence, space, and service standards. It is located in the heart of the exclusive

Diplomatic Enclave, approximately 14 km (25 min) from the International Airport; offering a

superb view of Delhi’s green belt – the forested ridge. The hotel started its operation in the

year 1977.

One of the real potentials for reducing pollution and increasing efficiency lies in upgrading

buildings. Hoteliers are realizing that the addition of sustainable features and renewable

technologies to existing buildings—could, in the long run, prove the low-cost solution to

improved environmental performance. Hotel ITC Maurya in New Delhi has set an example

by pioneering the successful use of solar technology for satisfying its thermal energy needs.

Concentrated Solar System in ITC Maurya, New Delhi

The Maurya faced several hurdles when it decided to go for the use of solar systems to reduce

the use of polluting fuels. There was no precedent of any such installation. There were issues

of economic feasibility to space constraints. There were also basic questions like the best

application of such a solar system in a hotel, keeping in mind the cost vs. benefits and the

53

integration requirement; how to hide such a system so as to maintain the aesthetic look of the

hotel; and how to ensure that the system performs as promised, when many solar installations

are either dysfunctional or operating at very low efficiencies.

After studying the various requirements and constraints of the hotel, and understanding how

these can be technologically and economically met by harnessing solar energy, the Maurya

concluded that the use of solar thermal concentrating systems for all their thermal

requirements is most suitable. The steam generated by these dishes is used to provide either

steam or hot water for laundry, cooking, bathing.

Details about the Arun System

The two-dish ARUN system generates steam which is used for the hotel’s laundry, cooking

and other heating requirements.

• One of these ARUN dishes is installed on top of the existing banquet hall, while

the other installed on ground in the backyard of the hotel with a footprint area of

less than 3m x 3m.

• The ARUN dish tracks the sun from sunrise to sunset on two axes.

• Water circulates through the receiver coil which is placed at the focus of dish

transferring the thermal energy from the sun to the circulating water and

converting it to pressurized steam at 175°C at 8 bars.

This installation saves ITC an equivalent of almost 32,000-35,000 scm of PNG per annum.

This has also resulted in a reduction in CO2 emissions by almost 120-130 tons per annum.

Details about Thermax Solar System in ITC Maurya

Thermax has installed 8 Scheffler dishes in the hotel to produce steam which is used for

different application such as laundry, cooking etc.

Features

Modular

Maximum indigenization

Low structural cost

Commercially proven for non-power applications

High Efficiency for heating applications

54

Technical specifications and performance parameters

SOLAR PARABOLIC CONCENTRATOR RECIEVER

• Quantity -8 no.

• Material – Mild Steel

• Area- 16 m2

• Tracking Mechanism- Automatic

• Reflective Material- 2 mm

• Surface protection – Zinc chromate primer

with dual coat rubber High reflective mirror

glass

• Quantity – 8 no.

• Type – Circular

• Material – High grade steel mild

• Size – 50 cm Diameter

• Design pressure – 15 Kg/cm2

• Working Pressure – 10 Kg/cm2

Table 7: Performance parameters of solar system

Name of system installed

Solar steam generator

ARUN DISH

Type of collectors

Arun Dishes (2)

Collector area per dish 169 m2

Capacity of system 105 kg/hour/dish at 6 kg/cm2

Type of fuel saved by the system

PNG

Year of installation

2010

Name of manufacturer of the system

Clique Developments Private Limited

THERMAX SCHEFFLER

Type of collectors

Scheffler Dishes (8 no.)

Capacity of system

9 kg/hr/dish at 3 kg/cm2

Type of fuel saved by the system

PNG

Year of installation

2010

Name of manufacturer of the system

Thermax Limited

CAPITAL COST IMPLICATIONS

Cost of the system

165 Lakhs*

Subsidy availed

Rs. 24 Lakhs for Arun dishes

Rs. 30 Lakh for Scheffler dishes

Payback period

12 years**

Table 8: Details of solar system in ITC Maurya

*Includes cost of thermax dishes

**Including cost of both thermax and clique’s system

55

Concluding Remarks:

ITC Maurya has successfully demonstrated the use of solar systems in the hotel industry by

installing two ARUN and 8 Scheffler dishes for satisfying its thermal energy needs in

laundry, cooking, bathing and other applications. Not only has the system been operating

successfully, but the economics of the investment also makes a strong case for all hotels to

install such systems. Contrary to being an eye sore, the Solar system has become an attraction

for all its guests.

Today there are several solutions for hotels which are ready to think green, are visionary and

are ready to invest in the future of their business as well as the global environment. Adapting

to renewable sources of energy is one of the most beneficial and sensible long-term decisions

that any company can take. A large portion of the energy needs of a hotel can be catered to

by proven solar technologies. The use of an appropriate solar technology for various

applications can have a positive impact on the Indian energy and environmental scenario.

A typical Indian luxury hotel uses approximately 53% energy for Heating Ventilation and Air

Conditioning (HVAC), 18% for the lighting, 15% for the kitchen and rest for miscellaneous

use. The energy requirement in hotels for HVAC, laundry and cooking (i.e. more than 75% of

The total energy requirement) can be met through use of concentrating solar technologies

(CSTs). This will result in huge cost savings for hotels in long term.

Hoteliers please think green and go green

56

Bibliography

List of Documents

Principles, Classification and Selection of Solar Dryers by G. L. Visavale

Energtica India (Nov/ Dec 2011)

Renewable Watch/December 2011

Thermodynamics by P. K. Nag

Indian Renewable Energy Status Report/ Background Report for DIREC 2010/Oct 2010

Experimental Analysis of Scheffler Reflector Water heater by Rupesh J. Patil, Gajanan K.

Awari, Mahendra P. Singh

Design and development of a Parabolic Dish Solar Water Heater by Ibrahim Ladan

Mohammed

ARUN Solar Concentrator for Industrial Process Heat Applications by Dr. Shireesh B.

Kedare, Ashok D. Paranjape, Rajkumar Porwal

Solar Thermal Heat applications by CSTEP

Disha 2011 November

Solar Power Generation in India by S. S. Murthy

Introduction to the Revolutionary Design of Scheffler Reflectors by Wolfgang Scheffler

List of Websites

www.heatweb.com

www.cliquesolar.com

www.thermaxindia.com/

http://mnre.gov.in/file-manager/UserFiles/brief_swhs.pdf

http://www.fao.org/docrep/u2246e/u2246e02.htm

http://www.thermexcel.com/english/tables/vapeau1.htm