U.S. geothermal energy sector promising

By Haitham Haddadin

NEW YORK (Reuters) - Geothermal energy could fill a sizable chunk of United States electricity requirements if legislative, technological and other challenges are met, a senior U.S. Department of Energy official said.

"Geothermal is going and blowing, there isn't a big hold-up to it," Alexander Karsner, assistant secretary for energy efficiency and renewable energy, said at an energy conference Wednesday.

"The potential of the resource could potentially be up in the double digits of our total national generating capacity. That means 10, 15 to 20 percent, of U.S. generating capacity."

As oil prices have risen, so has interest in renewable energy such as wind, biofuels and geothermal energy, which is generated from drilling wells that let steam power turbines.

Karsner said the upper end of that forecast could take up to 50 years to fully realize. And to put things in perspective, total current U.S. geothermal energy output capacity is equal to the production capacity of two nuclear or coal-fired power generation plants, he added on the sidelines of the conference.

Still, the sector has witnessed big growth in recent years and was set to continue with the right technologies and policies in place, he said. For one, the industry's future growth is closely tied to continuation of production tax credits set by the government in the early 1990s, he added.

The U.S. geothermal output capacity stands at around 3,500 megawatts -- enough to power about 3 million homes -- with a similar amount in development, Karsner said.

The bulk of existing generating capacity, about 2,492 MW, lies in California, with the rest in Western states like Nevada, Utah and Hawaii, Karsner said.