Energy is an indispensable requirement in modern life. It may be manual or animal and mechanical or electrical. Electricity is used to operate various kinds of machines. Availability of energy is a pre-requisite of modern economic activities. There are several sources of energy; some of them are coal, petroleum, natural gas, solar energy, wind energy and hydel energy. Some of them are exhaustible and some are non-exhaustible. Sources of energy are categorized as conventional and non-conventional.