Geothermal Power

Newly installed geothermal energy in the U.S. has grown 5% or 147.05 megawatts (MW) since the annual survey in 2012 by the Geothermal Energy Association (GEA). The current installed U.S. geothermal capacity totals 3,386 MW, more than any other country in the world.

U.S. energy needs are on the rise, and experts are debating how to best rebalance the amount of fossil fuel and renewable energy required to meet those needs. Geothermal, which uses the heat of the earth to produce power, is right in the middle of the conversation. Geothermal energy accounts for about 3% of renewable energy-based electricity consumption in the U.S., according to the GEA.

Douglas Hollett, director of the Geothermal Technologies Office with the Department of Energy (DOE), says geothermal is ready to play a larger role. “Geothermal power has secured energy capacity for another 150,000 homes in 2012, 150 MW with the potential to deliver over 100,000 gigawatts [GW] in the future,” he says. Renewable energy generation is critical for meeting America’s electricity needs, and has more than doubled in the past four years as part of a government approach that includes renewables, oil and gas and nuclear

Unlike solar and wind, geothermal energy is available around the clock. Large-scale commercial geothermal plants supply baseload power, or power produced at a steady rate that is used to meet a large part of a utility company’s demand. But geothermal is also flexible. It can “firm intermittent power [like solar and wind],” says Karl Gawell, executive director of the GEA, “ramp up or down to fill the gaps.”

“As more and more intermittent power is brought online, flexible power that can firm the supply is highly sought after,” Gawell adds

The DOE is funding research, partnering with laboratories and universities and focusing on emerging technologies that address when a key geothermal component is lacking such as enough fluid or enough permeability. “The solution is engineering that subsurface to allow that missing part to be there,” Hollett says.

The agency has found success at the first three demonstration sites in Oregon, California and Nevada. Hollett says the resource potential of undiscovered conventional geothermal is about 30 GW and the resource potential of new Enhanced Geothermal System resources is 100 to 500 GW.

One obstacle to geothermal expansion is cost. “One well might cost $10 million,” says Gawell. “It doesn’t take many $10 million dry holes to chase away investors.”