Geothermal is in many ways the best option when it comes to generating clean, carbon-free energy.

The problem comes in the details.

The chasm between the promise and challenges facing geothermal are underscored in the latest annual report from the Geothermal Industry Association. Geothermal plants–which essentially extract heat from below the surface of the earth and use it to create steam for generators at power plants– account for 11.2 gigawatts of power capacity worldwide. Approximately 3.1 gigawatts worth of geothermal plants exist in the U.S.

Unlike wind or solar, geothermal power is not intermittent. Geothermal plants provide consistent, baseline-quality power decade after decade. A gigawatt of capacity of geothermal power is thus equivalent to 3 gigawatts of solar or wind. Geothermal wells only extract a fraction of subterranean heat as well so the environmental problems are somewhat minimal. Another plus: geothermal plants make little noise and occupy comparatively little real estate. Reno, my home town, gets approximately 20 percent of its power from the Galena geothermal plant operated by Ormat that sits behind a series of rolling hills at the southern edge of the city. Many locals don’t even know it’s there.

via What Ails Geothermal? Let’s Count the Ways – Forbes.