GEOTHERMAL-ENERGY - ELECTRICITY-GENERATION AND ENVIRONMENTAL-IMPACT

Geothermal energy is widely used as a reliable source of electricity generation. In 21 countries geothermal plants are in operation and have a combined installed capacity of over 6 000 MW. Technology now permits the utilization of a broad range of resources, from moderate-temperature to hypersaline brines, as well as natural steam with high levels of noncondensable gases. This paper describes geothermal energy conversion systems and the potential environmental impacts associated with geothermal plants. In comparison with alternatives, geothermal plants are among the most environmentally benign. Emissions abatement, water and land-use, and other aspects are discussed, along with the costs of environmental controls.