Non-conventional sources of energy: Today non-conventional sources of energy include wind, tides, geothermal heat, biogas, farm and animal waste including human excreta. All these sources are renewable or inexhaustible. They are inexpensive in nature.

These sources include the following:

1. Wind energy: It can be used for pumping water. It is used in irrigating farms in the countryside. Also, it can be used for generating electricity. It is estimated that wdnd alone can provide 2000 MW of electricity. The states of Gujarat, Tamil Nadu, Maharashtra and Orissa are better placed in regard to this energy. Areas with constant and high speed winds are suitable for the purpose.

2. Tidal energy: This is another inexhaustible and inexpensive source of energy. The Gulfs of Kutch and Cambay are ideally suited to develop electricity from the energy produced by high tides entering into narrow creeks.

3. Geo-thermal energy: India is not rich in this source. However, efforts are being made to utilize natural energy of the hot springs at Manikaran in Himachal Pradesh. Energy so produced can be used for running cold storage plants.

4. Energy from urban waste: A pilot plant for demonstration purposes had already been set up in Delhi to treat solid municipal waste for conversion into energy. It produces nearly 4 MW energy every jmar. Sewage in cities is used for generating gas and electricity.

5. Biogas based power plants: Biogas, farm wastes, rice husk are being used to produce electricity.

6. Farm animal and human wastes (Urja Gram): By using biogas, animal, poultry wastes and human excreta, gobar gas plants are being set up in villages. The power so produced is used for cooking, lighting homes and streets and meeting irrigation needs of the village. The plants are being set up both at individual and community or village levels. Nearly 3 million smokeless chullahas are in operation. This saves nearly 2 million tonnes of firewood.

7. Solar Energy: It is the most abundant, cheapest and inexhaustible source of energy produced from sunlight. Solar cookers are used in cooking food. Solar power is being used for cooking, water heating, water desalination, space heating, crop drying. Solar energy is going to be the energy of the future.