Compare and contrast biomass and hydroelectricity as sources of energy.
Bio-mass is renewable sources of energy. It mass is derived from dead plants and animal wastes. Therefore it is naturally replenished. Wood, gobar gas etc. are some of the examples of bio-mass.
Hydro-electricity is also renewable sources of energy. But it is obtained from the potential energy stored in water at a height. Energy from it can be produced again and again.