Geothermal Power Turns 50, Where is it Now?

Geothermal energy in the United States has reached its golden anniversary. 50 years ago, construction began on America’s first commercial-scale geothermal power plant just north of San Francisco. It was named The Geysers and has grown over the years from a single 11-megawatt power plant to a complex of 22 individual plants drawing energy from 350 wells and providing more than 1.5 gigawatts of renewable electricity to Californians. The Geysers is the largest geothermal power plant in the world. 

In fact, over the 50 years since the birth of geothermal, the United States has grown to be the world leader in geothermal production, led by California where more than 40 plants are in operation and provide 5 percent of the state’s electricity.

Geothermal in the United States

Currently, reports the Geothermal Energy Association, the U.S. has over 3 gigawatts of installed geothermal capacity. This energy comes from 77 power plants spread out over nine states. Seven new plants were brought online in 2009, and 188 projects in 15 states are being considered or under development — projects that would add up to another 8 gigawatts of capacity. Geothermal power has seen fairly steady growth since its inception in 1960, but is certainly enjoying the current rush to renewable energy and may just be entering its prime at the age of 50.

While California leads in existing geothermal production, Nevada is the state leader in new geothermal projects, with 3 gigawatts under production all by itself. Other western states are not far behind. Utah quadrupled its geothermal output last year, New Mexico tripled, Idaho doubled and Oregon reported a 50-percent increase. Louisiana, Mississippi and Texas all reported their first commercial geothermal projects earlier this year. Other states with geothermal projects in the works are Alaska, Arizona, Colorado, Hawaii, Washington and Wyoming.

Not surprisingly, the geothermal energy industry grew by 26 percent in 2009, according to the GEA, no doubt aided by roughly $800 million in investments in the same year. Furthermore, the Massachusetts Institute of Technology (MIT) and the U.S. Department of Energy have estimated that 100 GW of geothermal power could be produced by 2050, which would make the energy source’s 90th birthday party quite a celebration.

Geothermal also produces electricity at a rate much cheaper than other renewables, due in large part to its ability to operate much like a conventional power plant does.

Ups and Downs of Geothermal

Geothermal’s main advantage over other renewable resources is its ability to provide 24/7 baseload power, avoiding the intermittency and complicated storage problems plaguing wind and solar power. The only problem for geothermal is caused (and fixed) by plant operations. If not operated wisely, a geothermal well can run dry. It is possible for a power plant to use up water faster than the Earth’s vast ecosystem can replenish it. Water is extracted from (or injected into) heated rock beneath the Earth and used to spin a steam turbine on its surface, creating electricity.

In response to this issue, closed loop systems have been developed that exchange heat with the “molten” water and then pump back down through a return well. In the case of Geysers, geothermal’s celebrated golden child, well operators pump in treated wastewater from urban centers to replenish the wells — another avenue to ensuring that geothermal remains a renewable resource.

Photo Credit: Richard C Norman via Flickr