Wood - It is obtained from fast growing trees like Butea, Casurina, Leucaena, Eucaplyptus, Melia, etc. The predominant mode of utilization of wood as an energy source is in the form of firewood, which is rather inefficient.

It is estimated that about 50% of the total wood harvested each year is consumed as firewood. The estimated requirement for firewood in India was 250 million tons in 1996, while the supply was only 80 million tons.