What are the environmental impacts of using geothermal energy?
Geothermal technologies offer many environmental advantages over conventional power generation: • Emissions are low. Only excess steam is emitted by geothermal flash plants. No air emissions or liquids are discharged by binary geothermal plants, which are projected to become the dominant technology in the near future. • Salts and dissolved minerals contained in geothermal fluids are usually reinjected with excess water back into the reservoir at a depth well below groundwater aquifers. This recycles the geothermal water and replenishes the reservoir. The City of Santa Rosa, California, pipes the city’s treated wastewater up to The Geysers power plants to be used for reinjection fluid. This system will prolong the life of the reservoir as it recycles the treated wastewater. • Some geothermal plants do produce some solid materials, or sludges, that require disposal in approved sites. Some of these solids are now being extracted for sale (zinc, silica, and sulfur, for example), making the
