Power Generation
INTRODUCTION
Electrical energy is generated by conversion of energy available in different forms from different natural sources such as pressure head of water, kinetic energy of blowing wind, chemical energy of fuels and nuclear energy of ratio active substances into electrical energy.
There are two ways of generating electrical power.
1. Conventional Methods of Power Generation: This method of power generation uses a prime-mover (turbine) for driving electrical machines (generators or alternators) which convert mechanical energy into electrical energy. The various popular methods of power generation by conventional methods are thermal, hydro and nuclear.
2. Non-conventional Method of Power Generation: In this method of power generation, electrical energy is generated without the use of prime-movers. The various non-conventional method of power generation includes solar cells, fuels cells, thermoelectric generation, solar cell power generation, wind-power generation, geo-thermal power generation, tidal power generation etc.
Various Sources of Energy
The various sources of energy by which electricity can be generated are wind, solar, fuels (such as diesel, coal), geothermal energy, ocean tides, biomass, hydro-energy etc. Nowadays, we are emphasizing more on solar-energy based electricity generation because it causes very less pollution in comparison to coal-based thermal power plants.
COMPARISON OF VARIOUS TYPES OF POWER PLANTS
| Items | Hydro-electric power plants | Steam power plants | Nuclear power plants |
|---|---|---|---|
| Site requirement | Huge water with sufficient water head should be available at the site. Located far from load centers. | Located near the load center but good transportation facility should be available to transport coal. | Located away from thickly populated areas to avoid radioactive pollution but, located near load center as possible. |
| Space requirement | Very large due to reservoir. | Less than hydro-electric plants. | Less than hydro and steam power plants, but more than others. |
| Auxiliaries requirements | Small | Large | Less than steam PP, but more than other PPs. |
| Simplicity and cleanliness | Most simple and no air pollution. | Less clean due to ash handling and high air pollution. | Nuclear waste disposal a major problem but, no air pollution. |
| Starting time | 5-10 minutes | 2-3 hours | 2-3 hours |
| Plant life | 30-50 years | 20-30 years | 20-30 years |
| Overall efficiency | Most efficient (80-85%) | 30-40% | 30-40% |
| Erection period | 10-15 years (maximum) | 3-5 years | 10-12 years |
| Maintenance requirement | Very low | Quite high | Very high |
| Capital cost | Quite high | Medium | Very high |
| Operating cost | Minimum (25-30 paise per kWh) | ₹ 1-1.25 per kWh | Quite low 30-35 paise per kWh |
| Overall generating cost | ₹ 1-2 per kWh | ₹ 2-3 per kWh | ₹ 1-1.5 per kWh |
| Transmission and distribution cost | Very high as located far from load center. | Moderate | Moderate |