Those sources of energy which are not based on burning of fossil fuels are called non conventional sources of energy.
ex wind energy , solar , biomass,.
moving of wind is known as wind energy.
it does not cause any pollution
it is a renewable source  of energy
as long as sun keep shinning the wind will keep blowing and gives us energy
dis advantages
wind energy farms cannot be established every where.
it requires large amount of area
the minimum wind speed necessary for satisfactory working is 15km\h. this is not always so.
wind energy farms are very expensive.