The Geothermal Energy Association (GEA) says geothermal development waned during the 1990s, but new developments in geothermal power have resumed since 2005, attributed to the extension of the federal production tax credit in 2005 to geothermal facilities, the ITC cash grant program, and the American Recovery and Reinvestment Act, coupled with growing state-level recognition of the value of renewable portfolio standards.
GEA released an Air Emissions Comparison and Externality Analysis report that touts the environmental benefits of geothermal power, including GEA’s estimate that geothermal provides approximately $88 million in externality benefits per year to California and $29 million to Nevadans by avoiding fossil fuel emissions.
According to the report, 27 plants came online between 2006 and 2012 in seven Western states, bringing the total installed capacity in the US to 3.38 GW. Today, geothermal power plants are currently online in eight states: Alaska, California, Hawaii, Idaho, Nevada, Oregon, Utah, and Wyoming. Additionally, 175 geothermal projects are currently in development, which could add about 2,500 MW to US installed capacity in the next decade or so.
But the report warns that geothermal power is being underutilized because federal tax credits, which tend to be modified every few years, are reaching their end dates. For geothermal plants with long lead times, the legislative uncertainty means the effects of the incentive are diminished.
Recently, the US Department of Energy recognized the nation’s first commercial enhanced geothermal system (EGS) project to supply electricity to the grid. EGS technologies utilize directional drilling and pressurized water to enhance flow paths in the subsurface rock and create new reservoirs, capturing energy from resources that were once considered uneconomical or unrecoverable.