The main sources of alternative energy are:
1. Biomass: The basic source of bioenergy is sunlight. Out of total solar energy reaching earth, 0.2% of light is stored in plants in the form of biomass. All those materials formed from photosynthesis is called bio-mass. We can include all living organisms and their by-products in the category of biomass, which may be a source of energy.
Example:
- Plants containing lignocellulose: Eucalyptus, Leucaena, Maize, Sugarcane, Sugarbeet, Pine tree.
- Aquatic plants: Water hyacinth (Jal Kumbha).
- Waste products: Manure, refuse, wood, remains of cropsstraw, lemon rinds, remains of sugarcane, jaggery, fibres of coconut, flower-leaf, cow-dung etc.
2. firewood: Wood is the most commonly used fuel and is being used by a human for a long time back. About 50% of the Indian population use wood fuel for domestic and cottage industries because it is easily available and its use does not require specific knowledge.
It is used in a maximum amount in developing and undeveloped countries of Asia and Africa. Use of wood as fuel in our country is a major cause of deforestation and destruction of wildlife and also a major source of environmental pollution in our country.
Salient features of good wood fuel:
- It must have high combustion potential.
- It must have high-calorie value so as to generate more heat on combustion.
- It should not split and break into pieces on combustion.
- The amount of moisture and resin content should be low.
- It should not produce stinking odour on combustion and should produce minimum smoke.
3. Gobar gas or Biogas: More than 70% population of our country resides in villages where animal livestock is plentiful and easily available. Generally, the dung obtained from cattle is used for burning by making cow-dung cakes. Instead of burning, the dung should be utilized for making biofertilizer. For this, the dung should be filled into big pits regularly. Pits should be made on a higher level and its depth should not exceed one metre.
