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SPV systems have found applications in households, agriculture,
telecommunications, defence, and railways among others. In the last two decades, the cost of PV has gone down by more than 10 times, increasing accessibility for dispersed rural applications. Costs are expected to reduce further thus creating more potential About 62 MW aggregate capacity (about 10,50,000 individual PV systems and power plants) have been installed for various applications. In addition, PV products of 48 MW aggregate capacity have been exported.
Under MNES's PV programme, around 8.20 lakh systems have been installed - aggregating to about 29 MW. This includes 509,894 solar lanterns, 2,56,673 home lighting systems, 47,969 street lighting systems, and 5,000 water pumping systems. About 3.97 MWp of aggregate capacity of stand-alone and
grid interactive PV power plants have been installed as on March 31, 2003. These include State's own programmes also MNES is implementing two major
schemes for the deployment of stand-alone PV systems in the country:
Lighting systems, stand-alone power plants and other specialized systems, implemented mainly through
SNAs/departments/corporations, Aditya solar shops operated by Manufacturers Associations and NGOs.
Water-pumping systems for agriculture and related uses, implemented through IREDA and SNAs West Bengal,
Rajasthan, hilly regions of Uttar Pradesh, Ladakh, Lakshadweep, Andaman and Nicobar Islands are prominent regions where SPV home lighting systems and power plants are in demand. About 3600 remote villages and hamlets have been electrified with SPV systems and power plants. Out of these 800 remote villages have been electrified during 2001-02 and 2002-03. Eleven power plants of 250 kWp aggregate capacity have been installed in Sagar Islands in West Bengal Aims and Targets.A wide range of power technologies exist which can make use of the solar energy
reaching Earth. These can be classified in a number of different ways.
Method of energy transformation:
A photovoltaic cell produces electricity directly from solar energy.
Direct solar power involves only one transformation into a usable form. For example:
Sunlight hits a photovoltaic cell (also called a photoelectric cell) creating electricity.
Hydroelectric power stations produce indirect solar power. The Itaipu Dam,
Brazil /Paraguay Vegetation uses photosynthesis to convert solar energy to chemical energy, which can later be burned as fuel to generate electricity.
Methane (natural gas) and hydrogen may be derived from the biofuel. Hydroelectric dams and wind turbines are powered by solar energy through its interaction with the Earth's atmosphere and the resulting weather phenomena. Ocean thermal energy production uses the thermal
gradients that are present across ocean depths to generate power. These temperature differences are ultimately due to the energy of the sun.
Solar technologies: Most solar energy used today is harnessed as heat or electricity.
Solar design is the use of architectural features to replace the use of grid
electricity and fossil fuels with the use of solar energy and decrease the
energy needed in a home or building with insulation and efficient lighting and
appliances.
Insulating shutters for windows to be closed at night and on overcast days. These trap solar heat in the
building. Fixed awnings positioned to create shade in the summer and exposure to the sun in the winter.
Movable awnings to be repositioned seasonally. A well insulated and sealed building envelope. Active thermal solar panels using a heat transfer fluid (water or antifreeze solution). These are heated by the sun and the heat is carried away by circulation of the fluid for domestic hot water or building heating or other
uses.
Solar heating systems: Solar heating systems are generally composed of solar thermal collectors, a fluid system to move the heat from the collector to its point of usage, and a
reservoir to stock the heat for subsequent use. The systems may be used to heat
domestic hot water or a swimming pool, or to provide heat for a heating circuit
. The heat can also be used for industrial applications or as an energy input for other uses such as cooling
equipment.
Solar thermal cooling: There are some new applications of thermal hot water, such as air cooling,
currently under development. The absorber machine works like a refrigerator.
It uses hot water to compress a gas that, once expanded, will produce an
endothermic reaction, which cools the air.
Concentrated Solar Power (CSP) Plants: A concentrating solar power
plant, Parabolic trough power plants are the most successful and cost-effective CSP system design at present.
Solar chimney: A solar chimney is a relatively low tech solar thermal power plant where air
passes under a very large agricultural glass house (between 2 and 30 km in
diameter), is heated by the sun and channeled upwards towards a convection
tower. It then rises naturally and is used to drive turbines, which generate
electricity.
Energy Tower: An Energy tower is an alternative proposal for the solar chimney. The "Energy
Tower" is driven by spraying water at the top of the tower; evaporation of water
causes a downdraft by cooling the air thereby increasing its density, driving
wind turbines at the bottom of the tower. It requires a hot arid climate and
large quantities of water, but it does not require a large glass house.
Solar pond: A solar pond is a relatively low-tech, low cost approach to harvesting solar
energy. The principle is to fill a pond with 3 layers of
water.
Solar chemical: Solar chemical refers to a number of possible processes that harness solar
energy by absorbing sunlight in a chemical reaction in a way similar to
photosynthesis in plants but without using living organisms. No practical
process has yet emerged.
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Solar cooking: A solar box cooker traps the Sun's power in an insulated box; these have been
successfully used for cooking, pasteurization and fruit canning. Solar cooking
is helping many developing countries, both reducing the demands for local
firewood and maintaining a cleaner environment for the cooks. The first known
western solar oven is attributed to Horace de Saussure.
Solar lighting: The interior of a building can be lit during daylight hours using fibre optic
light pipes connected to a parabolic collector mounted on the roof. The
manufacturer claims this gives a more natural interior light and can be used to
reduce the energy demands of electric lighting.
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Solar Cooker |
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