1. WHAT ARE THE BENEFITS OF USING GEOTHERMAL ENERGY?
Answer: Several attributes make it a good source of energy.
- First, it’s clean. Energy can be extracted without burning a fossil fuel such as coal, gas, or oil. Geothermal fields produce only about one-sixth of the carbon dioxide that a relatively clean natural-gas-fueled power plant produces, and very little if any, of the nitrous oxide or sulfur-bearing gases. Binary plants, which are closed cycle operations, release essentially no emissions.
- Geothermal energy is available 24 hours a day, 365 days a year. Geothermal power plants have average availabilities of 90% or higher, compared to about 75% for coal plants.
- Geothermal power is homegrown, reducing our dependence on foreign oil.
Learn more on our Energy Basics page.
2. WHY IS GEOTHERMAL ENERGY A RENEWABLE RESOURCE?
Answer: Because its source is the almost unlimited amount of heat generated by the Earth’s core. Even in geothermal areas dependent on a reservoir of hot water, the volume taken out can be reinjected, making it a sustainable energy source.
3. WHERE IS GEOTHERMAL ENERGY AVAILABLE?
Answer: Hydrothermal resources – reservoirs of steam or hot water – are available primarily in the western states, Alaska, and Hawaii. However, Earth energy can be tapped almost anywhere with geothermal heat pumps and direct-use applications. Other enormous and world-wide geothermal resources – hot dry rock and magma, for example – are awaiting further technology development. To see visual representations of geothermal energy sources, visit our maps page.
4. WHAT ARE THE ENVIRONMENTAL IMPACTS OF USING GEOTHERMAL ENERGY?
Answer: 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 resource even more valuable and environmentally friendly.benefits