The Geothermal Energy Association (GEA) has released an air emissions comparison and externality analysis showing geothermal energy provides benefits to public health and the environment as one of the least-polluting and most environmentally friendly forms of energy.
The analysis found binary geothermal plants produce virtually no greenhouse gases (GHG) and dry steam and flash geothermal plants put out only trace amounts of emissions. The study estimates the public benefits from renewable energy produced in California and Nevada are worth more than $117 million annually.
According to the report, geothermal energy emerges as one of the least polluting and environmentally unobtrusive forms of energy, having the lowest lifecycle emissions of any generating technology.
Dry steam and flash geothermal energy plants emit about 5 percent of the carbon dioxide, 1 percent of the sulfur dioxide, and less than 1 percent of the nitrous oxide emitted by a coal-fired plant of equal size; and binary geothermal plants produce near-zero emissions. This is advantageous to public health, since many of the pollutants released in energy production carry negatives health consequences.
Additional benefits of geothermal energy include less land degradation, air emissions and environmental harm; greater fuel diversity; and improved national security through the use of an indigenous energy source. Geothermal energy also adds to the economy by paying substantial property taxes and providing significant long-term local employment.
This analysis updates a 2005 paper published in the Electricity Journal and expands upon the methodology by incorporating more atmospheric pollutants into the calculation. The new information showed GEA researchers the benefit of producing power using geothermal sources — as opposed to fossil fuels — is worth 3.5 cents for coal, and 1 cent for natural gas per kWh. Additionally, GEA estimates geothermal provides about $88 million in externality benefits per year to California and $29 million to Nevadans by avoiding fossil fuel emissions.