Non Conventional Sources Power Generation
- The fossil fuels are the main fuels for thermal power generation and they will get exhausted eventually in coming few years. Therefore, other systems based on non-conventional and renewable sources are being tried by many countries in the world. These sources are solar, wind, sea, geothermal and bio-mass.
- Solar energy can be a major source of power. Its potential is 178 billion MW which is about 20,000 times the world’s demand. But unfortunately it could not be developed on a large scale up till now. Sun energy can be utilized as thermal and photovoltaics. The thermal energy is currently being used for steam and hot water production.
- Wind energy uses the high wind velocity available in certain parts of the world. California State in U.S.A., generates 500 MW by Installing 900 wind turbines based on wind mills. Wind energy is used for pumping the water or power generation. A minimum wind speed of 3 m/s is needed. This is considered to have a high efficiency.
- Coastal, hilly and valley areas are suitable for operation of wind mills. In India, it is estimated that power between 20,000 to 25,000 MW can be developed in coastal areas of Gujarat, Maharashtra and Tamilnadu. Number of experimental stations have been set up. The maximum power generated from any single unit is about 1 MW.
- Geothermal energy derives its heat from the centre of the earth , and it is estimated that a power to the extent of 3400 MW can be produced in New Zealand, USA, Japan and Ice land. Philippines generates a power of 700 MW. In India, there are no major exploitable sources. Geothermal energy can be used for cooling by using heat for vapour absorption system.
- Energy from seas can be utilized as a wave, tidal or ocean thermal energy. About 13 kW per meter height of wave can be generated. In Kerala state, a plant is used to produce energy of 445000 KWH/year. This station generates about 75 kw in the months when sea is calm and 120-150 kW in months June-September.
- Ocean thermal energy conversion utilizes the temperature difference between warm surface Sea water at about 28°C and the cold deep sea water at 5-7°C at a depth of 800-1000 m in tropical area.
- India as a large potential along the coastal length from Bombay to Vishakapatanam.
- Tidal energy is the energy that can be trapped from sea. France and USSR developed this source by installing 240 MW and 400 MW plants respectively.
- In India, the Gulf of Kutch, Gulf of Cambay, and Suderbans are potential sites where such plants can be installed. The potential of sea is estimated as 50,000 MW from ocean thermal energy conversion, 8000 MW from tidal energy and 40,000 MW from wave energy.
- Bio-mass is another renewable source of energy in the form of wood, agricultural residues, etc. The potential for agricultural residues is estimated as 480 mt with residues from food grains contributing about 100 mt. These can be burnt directly to generate steam for use in turbines for power generation, or a gas be prepared from them which can further be used in gas engines for agricultural pumping or power generation.
- Such type of power generating plants upto 1 MW are tried but it is necessary to try for bigger sizes. The main problem is that agricultural residues is in the process of their collection.
- In case of forest wood, the requirement of wood being 250 to 300 m, and it is not readily available. Now the efforts are being made for cultivating quick growing trees for use in power generation.
- Similarly biogas obtained by anaerobic digestion of animal dung and sewage is also suitable for use in Internal combustion engines. Bio-mass may prove useful for localized power generation In rural areas where electric transmission lines have not reached.