Design aspect of Solar panel operated ventilation system or Airconditioner for avoiding Heat-stroke in Car using

 

Heatstroke-

 Heatstroke (or sunstroke) is a heat illness defined as a body temperature of greater than 40.6 °c (105.1 °F) due to environmental heat exposure with lack of thermoregulation.

It happens due to lack of water in body so that body temperature becomes more than the 40.6⁰c.

Fact and Causes of Heatstroke-

When car is parked in 25°C ambient condition under normal sunlight and car inside temperature is 22°C, within 15 minute the inside temperature rises to 48°C even when window is partially open.

This is due to greenhouse effect of interior of Car. The glasses passes the visible light(sun light) but does not allow to IR radiation(heat waves) to come out. Due to which temperature increases very fast inside the car.

The human body wants to stay at 98.6 degrees F(37⁰ C). The only way to stay at 98.6 is to sweat. By putting moisture on the skin and letting it evaporate, our body can cool itself very effectively and keep its temperature in the proper range.

At 48-50 ⁰C the rate of sweating becomes very much so human body needs lots of water. Due to unavailability of water body temperature increases very fast and leads to heat stroke.

Effect of heatstroke-

Sometimes parents leaves their child in the car and goes for shopping or other purposes. The heatstroke in car leads to death of the child inside. Many cases have been reported in this regard.

Due to high temperature of the car seat and inside air, if the persons comes to drive the car, he has to run the A. C. at very high cooling rate for few minute which leads to more fuel consumption.

Also sometimes, Car driver stays inside the car and run the car engine to cool it, which leads to much more fuel consumption.

Following are few designs-

Design-1

Targeted for lower end customer and less stylish design-

·         A solar vehicle ventilator also called solar car vent or solar car fan

·         Sun's energy converted  into the low-voltage electricity required to drive a small fan

·         The fan blows stale, hot air out of your vehicle and draws fresher air in.

Features -

1) Auto cool solar powered car fan

2) Auto cool is the revolutionary solar powered ventilation system to keep it up to 30 C cooler than it would normally be

(3) Being compact, it fits in any car window and does not need batteries

Specification -

 Colour: Same as car

 Item size: 14.5x 11 x 6cm

 Solar panel size: 10x7 cm

 Cost: $ 10

 Package item: 342 g

Design-2

Design for upper end customer and good looking design

•      Solar panel on the top of CAR will be placed.

•      Can give enough power to run a fan for good Ventilation

•      With use of high efficiency panel Air-condition Also can be run.

·         Area available= 3m²

·         Power available by panel= 3*150= 450 W_p

·         Panel cost(for m-c Si )= 23,000 INR

·         Ventilation system cost= 5,000 INR

·         Installation cost= 4,000 INR

·         Total cost= 32,000 INR

·         Can maintain temperature near to the ambient condition

Design-3

Design for long cars and more cooling requirement design

• Foldable panel design
• Can give large area to absorb irradiance
• Air-conditioning system can be used  cool the car
• Panel will give continuously energy at low power, it will be stored in the battery, battery will give power to charge super-capacitor at low power for more time. To run AC Super-capacitor will give high power for short time.

• On long Car available total area available is= 7 m²
• So panel can be give power= 7x150= 1050 W_p

•      This Panel will cost= 50,000 INR

•      Super capacitor cost= 10,000 INR

•      BLDC motor cost= 3,000 INR

•      Installation cost= 5,000 INR

• Total cost= 68,000INR
• Can maintain temperature ~ 22⁰C

Prototype design result-

we designed a solar panel driven Thermo- electric based cooler in a closed box of around 1ft x1ft x 0.5 ft and measured the test data as follwing. 

Conclusion-

•      This is good idea to solve current problems of sunstroke in Cars by using solar power.

•      By using this idea we can able to reduce AC operating cost. 

•      It will reduces fuel consumption so it will cut carbon footprint.

A report on steam reformer and fuel cell cooling techniques and fuel cell testing process

 

STEAM REFORMER-

Steam reforming (SR), sometimes referred to as steam methane reforming (SMR) uses an external source of hot gas to heat tubes in which a catalytic reaction takes place that converts steam and lighter hydrocarbons such as methane, biogas or refinery feedstock into hydrogen and carbon monoxide (syngas). Syngas reacts further to give more hydrogen and carbon dioxide in the reactor. The carbon oxides are removed before use by means of pressure swing adsorption (PSA) with molecular sieves for the final purification. The PSA works by adsorbing all impurities from the syngas stream to leave a pure hydrogen gas.

Reforming  Reactions -
The reforming of any hydrocarbon is as follows:

Process  Scheme
Steam reforming can be performed for a wide range of fuels, but the process itself is similar in all cases.

Process for on-board steam reforming.

The fuel of the vehicle is pre-heated in a heat exchanger by the hot exhaust gas of the engine. Before entering the heat exchanger, hot water (steam) is separated from the exhaust gas and used in the steam reformer. Because steam reforming requires water, the usage of a water separator for the exhaust gas makes on-board water storage redundant. In the steam reformer the heated fuel and the steam are converted to syngas, which is then burned in the engine to produce duty.

Advantages-
Some advantages of steam reforming are:

1. The burning value of the fuel is increased, because steam reforming is an endothermic process, resulting in a more efficient fuel.

2. Steam reforming produces less exhaust emissions than burning the feedstock fuel

Disadvantages-
The disadvantages of steam reforming are:

1. Soot is formed in the reactor at high temperatures

2. Water sequestration from the exhaust is not easy to perform

FUEL CELL COOLING TECHNIQUES-

As we know that that the fuel cell efficiency is practically 50%. Which means the half of the energy produced is wasted as heat in the stack, which gives rise to increase in temperature. The increase in the temperature dries the membrane and reduces the conductivity so that fuel cell stops working. There are many types of fuel cell cooling techniques which depends on size and type of use of fuel cell-

1. AIR cooling- It is one of the best method of cooling. Air cooling is done by passing air at high velocity through the porous graphite flow field. Air cooling can be used for the stack of size 2KW. 

2. LIQUID cooling- liquid cooling technique basically involves the use of water. It is most used technique for cooling. In this method cold water is passed through the stack cooling plate. The cold water takes the heat produced within the stack with it and removes the heat in atmosphere and controls the temperature of fuel cell up to the desired level.

3. Heat plate cooling- Heat plate is very high heat conducting plate. Heat plate is placed after 2 -3 MEA in the stack. It absorbs the heat from the stack and releases in the atmosphere.

4. Heat pipe cooling technique- heat pipe is a also a very high thermal conducting plate. Heat pipe is placed in the contact with the stack. It takes the heat generated in the stack and put it outside. So that it controls the temperature of stack.

5. Evaporative cooling of fuel cell- the evaporation of any liquid decreases the temperature of that liquid. Evaporation is possible at any temperature above the absolute zero. In the process of evaporation the molecule of liquid leaves out the liquid by taking the internal energy (temperature dependent) of liquid. So the temperature decreases. it is latest method of fuel cell cooling which is in the research stage. This method of cooling involves the use of wicking material which has capillary action. As we know that at the cathode side water is produced so we can utilize this water for cooling of fuel cell and humidification of hydrogen.  We can put the wicking material in the flow field of fuel cell which will absorb the water produced in the cathode side and will carry it to the anode side so that it can be used for the humidification of H2.

FUEL CELL TESTING SYSTEM- 

We have seen the testing of 1 KW stack.

To test the stack we have an automatic testing system which is controlled by computer. The user can give input to the system like temperature, humidity and flow rate of different gases. The hydrated H2 is supplied from the anode side. And the hydrated O2 is supplied from the cathode side. The testing machine takes controls of flow and humidity of these gases.

As we know that the fuel cell has near about 40-50% efficiency. So half of the power produced is wasted as heat in the stack. So temperature of stack increases very much. To control the temperature rise water is circulated through the stack.

There are many temperature probes which constantly measures the temperature of different part of fuel cell stack. There is also facility to measure the potential of each cell. Each cell potential is measured by voltmeter and is displayed on the computer.

To start testing first we connect all gases connection to the fuel cell. And we connect cooling water pipe also. Fuel cell current collector terminal is connected to the testing machine which is capable to apply different load.

We supply heated H2 and O2 through humidifier. So that the fuel cell stack temperature increases and causes the activation of catalyst and the hydrated gas causes good conductivity of membrane. The PEMFC can be operated nearly 90 degree.

As the temperature of fuel cell increases the open circuit voltage of cell increases. Once the cell temperature reaches nearly 75-80 then we can apply load to take current from the fuel cell.

The fuel cell being tested had 36 cell, So that it is giving near about 35 V on open circuit. We can plot V-I characteristics (polarisation curve) of fuel cell. When we start taking current so many loses in the FC starts which increases the temperature of FC. So we have to start stack cooling system to stop the temperature increase of the stack. If we not stop the temperature rise then it will make the membrane dry and reduce the conductivity of fuel cell so FC stops working.

As we start taking current fro the fuel cell the voltage start decreasing. The rate of decrease in the voltage is not constant all over the curve.

As the current starts increasing the first loss that begin is activation loss after some more increment in the current the ohmic loos becomes significant.

Polarisation curve of Fuel cell

Further increase in the current leads to concentration polarization(mass transfer) losses.

Activation losses are caused by the slowness of the reactions taking place on the electrode surface. The voltage decreases somewhat due to the electrochemical reaction kinetics. This can be seen in the left-hand section of the current-voltage curve above.

The comic losses result from resistance to the flow of ions in the electrolyte and electrons through the cell hardware and various interconnections. The corresponding voltage drop is essentially proportional to current density, hence the term "ohm losses".

Mass transport losses result from the decrease in reactant concentration at the surface of the electrodes as fuel is used. At maximum (limiting) current, the concentration at the catalyst surface is practically zero, as the reactants are consumed as soon as they are supplied to the surface.

STATCOM

overview-
Electrical loads both generate and absorb reactive power. Since the transmitted load often varies considerably from one hour to another, the reactive power balance in a grid varies as well. The result can be unacceptable voltage amplitude variations, a voltage depression, or even a voltage collapse.

Similarly to the SVC the STATCOM can provide instantaneous and continuously variable reactive power in response to grid voltage transients, enhancing the grid voltage stability. The STATCOM operates according to voltage source principles, which together with unique PWM (Pulsed Width Modulation) switching of IGBTs (Insulated Gate Bipolar Transistors) gives it unequalled performance in terms of effective rating and response speed. This performance can be dedicated to active harmonic filtering and voltage flicker mitigation, but it also allows for a STATCOM to be comparatively downsized, its footprint can be extremely small. ABB has branded this high performance STATCOM concept SVC Light®.

Installing a STATCOM at one or more suitable points in the network will increase the grid transfer capability through enhanced voltage stability, while maintaining a smooth voltage profile under different network conditions. The STATCOM provides additional versatility in terms of power quality improvement capabilities.

STATCOM/SVC Light Technology

SVC Light is based on a technology platform also used for HVDC applications (HVDC Light). The most important building block is the Voltage Source Converter (VSC) equipped with Insulated Gate Bipolar Transistors (IGBTs) that are controlled by Pulse Width Modulation (PWM). A VSC is capable of both generating and consuming reactive power. If required, air core reactors and high voltage AC capacitors can be used along with the VSC as additional reactive power elements to achieve any desired range.

STATCOM/SVC Light Principle

SVC Light can be seen as a voltage source behind a reactance. Physically it is builtlas a three-level inverter operating on a constant DC-voltage. It provides reactive power generation as well as absorption purely by means of electronic processing of voltage and current waveforms in a voltage source converter (the grid will see it as a synchronous machine without inertia). This means that capacitor banks and shunt reactors are not needed for generation and absorption of reactive power, facilitating a compact design, a small footprint. The high switching frequency of IGBT allows extremely fast control, which can be used in areas such as mitigation of voltage flicker caused by electric arc furnaces, voltage balancing, harmonic filtering and robust grid voltage recovery support. A DC capacitor bank is utilized to support and stabilize the controlled DC voltage needed for the converter operation. Voltage source converters connected in "back-to-back configuration" between two AC busbars have the capability to operate with active power allowing a Dual Purpose scheme to be feasible. Using such a back-to-back configuration enables active power transfer between two AC grids (synchronous or asynchronous or even with different frequencies) while, simultaneously, the converters provide reactive power support to the AC networks. 

Urbanized environmentally friendly grid voltage support, a case story.

Urbanisation seems to be an ever-present force, more or less worldwide. But another trend in the opposite direction involves the relocation of electricity production to places far away from the city centers. Our favourite working and living places shall become cleaner and the aging machines that brought people together are now retired, often along with the factories they initially supported. Computers and air-conditioning follow people downtown. The result is that the growth of city centers increases the stress on the power transmission system, consuming considerable reactive power in a destabilising manner.

Given this helicopter perspective, it becomes apparent that it is not straightforward simple to retire old downtown workhorses. The authorities in Austin, Texas were faced with this problem as a down-town gas/oil fired plant was doomed due to its environmental impact. The introduction of extremely compact STATCOM (in the form of SVC Light®) technology greatly facilitated for the municipal utility Austin Energy to take a fast-track approach for the closing of the power plant, while maintaining adequate voltage stability margins in the grid operation. Within the timeframe of two years, all the pre-project activities (studies, specification, supplier selection), design, delivery, installation and commissioning of the approximately +100Mvar/138kV STATCOM was completed. It went into commercial service in December 2004. The Austin example shows how elegantly STATCOM technology can replace a generator, or more correctly, the voltage support capability of the generator. It does so cost efficiently and with a minimum of environmental impact. 

SEMINAR ON SOLAR POWER PLANT

                                                                                                         

1. Introduction

            Energy is considered a prime agent in the generation of wealth and a significant factor in economic development. Limited fossil resources and environmental problems associated with them have emphasized the need for new sustainable energy supply options that use renewable energies. Solar thermal power generation systems also known as Solar Thermal Electricity (STE) generating systems are emerging renewable energy technologies and can be developed as viable option for electricity generation in future. This paper discusses the technology options, their current status and opportunities and challenges in developing solar thermal power plants in the context of India. To make solar high flux, with high energetic value originating from processes occurring at the sun's surface at black-body-equivalent temperatures of approximately 5800 K usable for technical processes and commercial applications, different concentrating technologies have been developed or are currently under development for various commercial applications. Such solar thermal concentrating systems will undoubtedly provide within the next decade a significant contribution to efficient and economical, renewable and clean energy supply.

2. Solar energy potential

India is located in the equatorial sun belt of the earth, thereby receiving abundant radiant energy from the sun. The India Meteorological Department maintains a nationwide network of radiation stations, which measure solar radiation, and also the daily duration of sunshine. In most parts of India, clear sunny weather is experienced 250 to 300 days a year. The annual global radiation varies from 1600 to 2200 kWh/m², which is comparable with radiation received in the tropical and sub-tropical regions. The equivalent energy potential is about 6,000 million GWh of energy per year. Figure 1 shows map of India with solar radiation levels in different parts of the country. It can be observed that although the highest annual global radiation is received in Rajasthan, northern Gujarat and parts of  Ladakh region, the parts of Andhra Pradesh, Maharashtra, Madhya Pradesh also receive fairly large amount of radiation as compared to many parts of the world especially Japan, Europe and the US where development and deployment of solar technologies is maximum.

            

3. India’s power scenario

Fig3.1India’s power scenario

India’s current electricity installed capacity is 135 401.63MW. Currently there is peak power shortage of about 10 % and overall power shortage of 7.5 %. The 11^th plan target is to add 100 000 MW by 2012 and MNRE has set up target to add 14500 MW by 2012 from new and renewable energy resources out of which 50 MW would be from solar energy. The Integrated Energy Policy of India envisages electricity generation installed capacity of 800 000 MW by 2030 and a substantial contribution would be from renewable energy. This indicates that India’s future energy requirements are going to be very high and solar energy can be one of the efficient and eco-friendly ways to meet the same

4. Solar thermal power generation technologies

Solar Thermal Power systems, also known as Concentrating Solar Power systems, use concentrated solar radiation as a high temperature energy source to produce electricity using thermal route. Since the average operating temperature of stationary non-concentrating collectors is low (max up to 120⁰C) as compared to the desirable input temperatures of heat engines (above 300⁰C), the concentrating collectors are used for such applications. These technologies are appropriate for applications where direct solar radiation is high. The mechanism of conversion of solar to electricity is fundamentally similar to the traditional thermal power plants except use of solar energy as source of heat.

In the basic process of conversion of solar into heat energy, an incident solar irradiance is collected and concentrated by concentrating solar collectors or mirrors, and generated heat is used to heat the thermo fluids such as heat transfer oils, air or water/steam, depending on the plant design, acts as heat carrier and/or as storage media. The hot thermo fluid is used to generated steam or hot gases, which are then used to operate a heat engine. In these systems, the efficiency of the collector reduces marginally as its operating temperature increases, whereas the efficiency of the heat engine increases with the increase in its operating temperature.

 

5. Concentrating solar collectors

Solar collectors are used to produce heat from solar radiation. High temperature solar energy collectors are basically of three types;

a. Parabolic trough system: at the receiver can reach 400° C and produce steam for generating electricity.

b. Power tower system: The reflected rays of the sun are always aimed at the receiver, where temperatures well above 1000° C can be reached.

c. Parabolic dish systems: Parabolic dish systems can reach 1000° C at the receiver, and achieve the highest efficiencies for converting solar energy to electricity.

Fig5.1 Central receiver

6. Parabolic trough collector system

Parabolic trough power plants are line-focusing STE (solar thermal electric) power plants. Trough systems use the mirrored surface of a linear parabolic concentrator to focus direct solar radiation on an absorber pipe running along the focal line of the parabola. The HTF (heat transfer fluid) inside the absorber pipe is heated and pumped to the steam generator, which, in turn, is connected to a steam turbine. A natural gas burner is normally used to produce steam at times of insufficient isolation. The collectors rotate about horizontal north–south axes, an arrangement which results in slightly less energy incident on them over the year but favours summertime operation when peak power is needed.

The major components in the system are collectors, fluid transfer pumps, power generation system and the controls. This power generation system usually consists of a conventional Rankine cycle reheat turbine condenser cooling water is cooled in forced draft cooling towers. These type  of power plants can have energy storage system comprising these collectors usually have the energy storage facilities. Instead they are couple to natural gas fired back up systems. A typical configuration of such systems is shown in Figure 2 .

Fig6.1 Parabolic dish collector

7. Configuration of PTC solar thermal power plant

Fig7.1Configuration of PTC solar thermal power plant

                   These systems were commercialized in 1980’s in California in the United States. LUZ Company installed nine such plants between 1980–1989 to taling to 350 MWe  capacity. These plants are commonly known as SEGS (solar electric generator systems). SEGS uses oil to take the heat away: the oil then passes through a heat exchanger, creating steam which runs a steam turbine.

8 .Solar electric generator system (SEGS)

                              Fig8.1Schematic of solar electric generator system (SEGS)

Besides research and development in components and materials, two major technological developments are under way; 1.Integration of parabolic trough power plants in Combined Cycle plants and, 2. Direct steam generation in the collectors' absorber tubes. Using direct solar steam generation the HTF and water heat exchanger will no longer be required resulting in improvement of the efficiency conditions can be achieved which increases overall efficiency of cycle.

Plataforma Solar de Almería's SSPS-DCS plant in Spain is also another example of this technology.

9. Power tower system

In power tower systems, heliostats (A Heliostat is a device that tracks the movement of the sun which is used to orient a mirror of field of mirrors, throughout the day, to reflect sunlight onto a target-receiver) reflect and concentrate sunlight onto a central tower-mounted receiver where the energy is transferred to a HTF. This energy is then passed either to the storage or to power-conversion systems, which convert the thermal energy into electricity. Heliostat field, the heliostat controls, the receiver, the storage system, and the heat engine, which drives the generator, are the major components of the system.

For a large heliostat field a cylindrical receiver has advantages when used with Rankine cycle engines, particularly for radiation from heliostats at the far edges of the field. Cavity receivers with larger tower height to heliostat field area ratios are used for higher temperatures required for the operation of  Brayton cycle turbines.

Fig9.1 Schematic of power tower system

These plants are defined by the options chosen for a HTF, for the thermal storage medium and for the power-conversion cycle. HTF may be water/steam, molten nitrate salt, liquid metals or air and the thermal storage may be provided by PCM (phase change materials). Power tower systems usually achieves concentration ratios of 300–1500, can operate at temperatures up to 1500^o C. To maintain constant steam parameters even at varying solar irradiation, two methods can be used:

􀂃Integration of a fossil back-up burner; or

􀂃Utilization of a thermal storage as a buffer

By the use of thermal storage, the heat can be stored for few hours to allow electricity production during periods of peak need, even if the solar radiation is not available. The modern R&D efforts have focused on polymer reflectors and stretched-membrane heliostats. A stretched-membrane heliostat consists of a metal ring, across which two thin metal membranes are stretched. A focus control system adjusts the curvature of the front membrane, which is laminated with a silvered-polymer reflector, usually by adjusting the pressure in the plenum between the two membranes.

                   Examples of heliostat based power plants were the 10 MWe Solar One and Solar Two demonstration projects in the Mojave Desert, which have now been decommissioned. The 15 MW Solar Tres Power Tower in Spain builds on these projects. In Spain the 11 MW PS10 Solar Power Tower was recently completed. In South Africa, a solar power plant is planned with 4000 to 5000 heliostat mirrors, each having an area of 140 m².

10. Parabolic dish system

The parabolic dish system uses a parabolic dish shaped mirror or a modular mirror system that approximates a parabola and incorporates two-axis tracking to focus the sunlight onto receivers located at the focal point of the dish, which absorbs the energy and converts it into thermal energy. This can be used directly as heat for thermal application or for power generation. The thermal energy can either be transported to a central generator for conversion, or it can be converted directly into electricity at a local generator coupled to the receiver (Figure 5).

Schematic of Parabolic dish system

Fig10.1 Schematic of Parabolic dish system

The mirror system typically is made from a number of mirror facets, either glass or polymer mirror, or can consist of a single stretched membrane using a polymer mirror of thin metal stretched membrane.

The PDCs (parabolic dish collector) track the sun on two axes, and thus they are the most efficient collector systems. Their concentration ratios usually range from 600 to 2000, and they can achieve temperatures in excess of 1500^o C. Rankine-cycle engines, Brayton-cycle engines, and sodium-heat engines have been considered for systems using dish-mounted engines the greatest attention though was given to Stirling-engine systems.

The main challenge facing distributed-dish systems is developing a power-conversion unit, which would have low capital and maintenance costs, long life, high conversion efficiency, and the ability to operate automatically. Several different engines, such as gas turbines, reciprocating steam engines, and organic Rankine engines, have been explored, but in recent years, most attention has been focused on Stirling-cycle engines. These are externally heated piston engines in which heat is continuously added to a gas (normally hydrogen or helium at high pressure) that is contained in a closed system.

The Stirling Energy Systems (SES) and Science Applications International Corporation (SAIC) dishes at UNLV and the Big Dish in Canberra, Australia are representatives of this technology. Annexure–I presents the technical details of some existing solar thermal power plants globally.

11. Solar chimney

This is a fairly simple concept. As shown in figure 3.0 the solar chimney has a tall chimney at the centre of the field, which is covered with glass. The solar heat generates hot air in the gap between the ground and the gall cover which is then passed through the central tower to its upper end due to density difference between relatively cooler air outside the upper end of the tower and hotter air inside tower. While travelling up this air drives wind turbines located inside the tower. These systems need relatively less components and were supposed to be cheaper. However, low operating efficiency, and need for a tall tower of height of the order of 1000m made this technology a challenging one. A pilot solar chimney project was installed in

Spain to test the concept. This 50kW capacity plant was successfully operated between 1982 to1989. Figure 6 shows the picture of this plant. Recently, EnviroMission Limited, an Australian company, has started work on setting up first of its five projects based on solar chimney concept in Australia.

Fig11.1 50 kW Solar chimney pilot project, Manzanares, Spain

                   The Luz Company which developed parabolic trough collector based solar thermal power technology went out of business in 1990’s which was a major set back for the development of solar thermal power technology.

12. Solar thermal power generation program of India

In India the first Solar Thermal Power Plant of 50kW capacity has been installed by MNES following the parabolic trough collector technology (line focussing) at Gwalpahari, Gurgaon, which was commissioned in 1989 and operated till 1990, after which the plant was shut down due to lack of spares. The plant is being revived with development of components such as mirrors, tracking system etc.

A Solar Thermal Power Plant of 140MW at Mathania in Rajasthan, has been proposed and sanctioned by the Government in Rajasthan. The project configuration of 140MW Integrated Solar Combined Cycle Power Plant involves a 35MW solar power generating system and a 105MW conventional power component and the GEF has approved a grant of US$ 40 million for the project. The Government of Germany has agreed to provide a soft loan of DM 116.8 million and a commercial loan of DM 133.2 million for the project.

In addition a commercial power plant based on Solar Chimney technology was also studied in North-Western part of Rajasthan. The project was to be implemented in five stages.

In the 1^st stage the power output shall be 1.75MW, which shall be enhanced to 35MW, 70MW, 126.3MW and 200MW in subsequent stages. The height of the solar chimney, which would initially be 300m, shall be increased gradually to 1000m. Cost of electricity through this plant is expected to be Rs. 2.25 / kWh. However, due to security and other reasons the project was dropped.

BHEL limited, an Indian company in power equipments manufacturing, had built a solar dish based power plant in 1990’s as a part of research and development program of then the Ministry of Non-conventional Energy Sources. The project was partly funded by the US Government. Six dishes were used in this plant.

Few states like Andhra Pradesh, Gujarat had prepared feasibility studies for solar thermal power plants in 1990’s. However, not much work was carried out later on.

13. Opportunities for solar thermal power generation in India

Solar thermal power generation can play a significant important role in meeting the demand supply gap for electricity. Three types of applications are possible

1. Rural electrification using solar dish collector technology

2. Typically these dishes care of 10 to 25 kW capacity each and use sterling engine for power generation. These can be developed for village level distributed generation by hybridizing them with biomass gasifier for hot air generation.

3. Integration of solar thermal power plants with existing industries such as paper, dairy or sugar industry, which has cogeneration units.

Many industries have steam turbine sets for cognation. These can be coupled with solar thermal power plants. Typically these units are of 5 to 250 MW capacities and can be coupled with solar thermal power plants. This approach will reduce the capital investment on steam turbines and associated power-house infrastructure thus reducing the cost of generation of solar electricity

4. Integration of solar thermal power generation unit with existing coal thermal power plants. The study shows that savings of upto24% is possible during periods of high insolation for feed water heating to 241 ⁰C (4).

14.  Barriers

                   Solar thermal power plants need detailed feasibility study and technology identification along with proper solar radiation resource assessment. The current status of international technology and its availability and financial and commercial feasibility in the context of India is not clear. The delays in finalizing technology for Mathania plant have created a negative impression about the technology

15. Way ahead

Solar thermal power generation technology is coming back as commercially viable technology in many parts of the world. India needs to take fresh initiative to assess the latest technology and its feasibility in the Indian context. These projects can avail benefits like CDM and considering the solar radiation levels in India these plants can be commercially viable in near future.

                   The MNRE and SEC (Solar Energy Centre) should take initiative to study these technologies and develop feasibility reports for suitable applications. Leading research institutes such as TERI can take up these studies

16. Conclusion

                   Resource assessment, technological appropriateness and economic feasibility are the basic requirement of project evaluation.The solar tower power and point focusing dish type plants are being popular worldwide. In the pulp and paper industry, the moderate temperature is required for processing; and solar energy can effectively generate this amount of heat. The solar energy based power generating systems can play a major role towards the fulfilment of energy requirements of industry.

Fortunately, India lies in sunny regions of the world. Most parts of India receive 4-7 kWh of Solar radiation per square metre per day with 250-300 sunny days in a year. India has abundant Solar resources, as it receives about 3000 hours of sunshine every year, equivalent to over 5,000 trillion kWh. India can easily utilize the Solar energy or Solar Power. Today the contribution of Solar power with an installed capacity of 9.84 MW, is a fraction (< 0.1 percent) of the total renewable energy installed 13, 242.41(as on 31st October 2008 by MNRE).

 Solar power generation has lagged behind other sources like wind, small hydropower  biomass  etc .But now realizing the potential of Solar energy, Prime Minister of India unveiled a National Climate Change Action Plan in June 2008. The plan will be implemented through eight missions with main focus on Solar energy in the total energy mix of the country.

17. References

1. Annual Report, Ministry of New and Renewable Energy Sources, 2005-06.

2. Beerbaum B. and G.Weinrebe Solar thermal power generation in India: a techno-economic analysis, Renewable Energy, 21, 2, 1 2000, 153-174.

3. Duffie J.A.,Beckman W.A.Solar engineering of thermal processes. New York: Wiley; 1991.

4. Kalogirou S. A., Solar thermal collectors and applications, Progress in Energy and Combustion Science, 30, 3, 2004, 231-295.

5. Kreith F, Kreider J.F. Principles of solar engineering, New York: McGraw-Hill; 1978.

6. Winter C. J., R. L. Sizmann and L.L. Vant-Hull, Solar Power Plants: Fundaments, Technology and System Economics, Springer-Verlag, New York, USA.

7. Status Report on Solar Thermal Power Plants by Pilkington Solar International, Germany

8. National Renewable Energy Laboratory (USDOE), USA

9. http//en.wikipedia.org/wiki/Solar_Thermal_Energy