PRODUCING ELECTRICITY FROM RENEWABLE ENERGY SOURCES

Power generation systems using renewable resources have some advantages over traditional fossil-fuel-powered generation systems. Most renewable power technologies do not produce greenhouse gases and emit far less pollution than burning oil and coal to generate electricity. Renewable sources of energy are self-replenishing and clean, and currently contribute 15% of the worlds energy supply. Solar power is expanding as technology improves and its cost becomes more competitive. Commercial wind turbines are now harnessing energy in over 65 countries, making wind power the world's fastest growing source of energy after solar. And geothermal energy is meeting a significant portion of electrical power demand in several developing countries. The fuel source may be free in most cases, but the generating equipment itself typically has a higher up-front cost than fossil-fuel-powered alternatives. Taken over the lifetime of the generating equipment, however, the cost of electricity power from renewable sources is, in some cases, approaching the cost of generating power from conventional sources, and each one of them is already economically feasible in certain applications. Renewable energy technologies also have some disadvantages. Solar and wind power are intermittent - they do not produce power if the sun is not shining or the wind is not blowing.