Currently the world is powered by the energy generated from the various non-renewable sources of energy like gas, coal and oil. These fuels are called fossil fuels, and are found buried deep within the Earth in limited quantities. The fossil fuels deposits will run out by the next century. This will affect the energy generation and will halt the progress of the mankind. Hence as a precautionary measure and from the viewpoint of reducing global warming, more and more sources of renewable energy are getting harnessed.
