Sustainable Energy refers to energy produced by using natural resources that are replenished in the regular course. Energy from the sun, wind energy, tidal energy, etc in addition to energy extracted from biomass and biofuels fall in this category.

We shall briefly look at the main renewable energy systems:



The sun has a surface temperature of aproximatelly 27 million deg. C. and dark age defense book amazon - just click the next web site - emits radiations covering a wide range of frequencies in all directions. A component of the radiations fall on the earth as it goes round the sun. Allowing for the many losses of the radiation on way to the planet, on an average we get aproximatelly 800 W/m2 of solar energy in the equator.
Solar radiations include infrared frequencies which give heat and also visible radiations which have light. The energy from the sun, therefore, can be used in a rather versatile manner. Photovoltaic cell-assemblies as arrays & panels are utilized in isolated homes and communities for providing electricity; they are also used in big power stations for energy supplies. Heat for industrial processes as well as for supplementing the large thermal power stations is supplied by utilizing the solar concentrators in large installations.