Home > Renewable Energy > Solar   Solar Thermal    Solar PV    Solar Passive    India is endowed with rich solar energy resource. The average intensity of solar radiation received on India is 200 MW/km square (megawatt per kilometre square). With a geographical area of 3.287 million km square, this amounts to 657.4 million MW. However, 87.5% of the land is used for agriculture, forests, fallow lands, etc., 6.7% for housing, industry, etc., and 5.8% is either barren, snow bound, or generally inhabitable. Thus, only 12.5% of the land area amounting to 0.413 million km square can, in theory, be used for solar energy installations. Even if 10% of this area can be used, the available solar energy would be 8 million MW, which is equivalent to 5 909 mtoe (million tons of oil equivalent) per year. However, solar energy is a dilute source. The energy collected by 1 m square of a solar collector in a day is approximately equal to that released by burning 1 kg of coal or 1/2 litre of kerosene. Thus, large areas are needed for collection. Besides, the efficiency of conversion of solar energy to useful energy is low. Therefore, the energy actually available would be order of magnitude lower than the aforementioned estimates. Nonetheless, it is obvious that solar energy can be a good source of meeting energy demands. On the applications side, the range of solar energy is very large. While at the high end there are megawatt level solar thermal power plants, at the lower end there are domestic appliances such as solar cooker, solar water heater, and PV lanterns. Then, in between, there are applications such as industrial process heat, desalination, refrigeration and air-conditioning, drying, large scale cooking, water pumping, domestic power systems, and passive solar architecture. Solar cookers and hot water systems based are gaining popularity in India and to a large extent attained commercial status. Solar energy can be harnessed to supply thermal as well as electrical energy. Those technologies that use solar energy resource to generate energy are known as solar energy technologies. Solar energy technologies consists of solar thermal technologies, which utilize sun's thermal energy and solar photovoltaic technology, which convert solar energy directly in to elecricity. Solar energy resource : Since the accurate information about solar energy resource at a specific location is crucial for designing appropriate solar system; solar energy resource assessment becomes an essential activity of any solar energy programme.