'High prices and climate change are definitely creating a renaissance in geothermal interest'
Volcanoes and hot springs could supply up to 25 per cent of America's power needs, energy experts have said.
As fuel prices soar, Alaskan officials announced the exploration of the state's volcanoes, saying they could be exploited to provide energy for thousands of homes.
Companies are being invited to lease the rights to explore geothermal resources beneath Mount Spurr, a snowcapped 11,070-foot volcano that most recently erupted in 1992 showering much of Anchorage with volcanic ash.
The state Division of Oil and Gas hopes the lease sale, due to go ahead in August, will be the first of many. It is also considering allowing exploration of the 4,134-foot Augustine Volcano, 171 miles southwest of Anchorage.
The move echoes a trend underway across much of the US as fuel prices, worries about dependence on foreign oil and climate change trigger a surge in geothermal projects, particularly in the West and along the Gulf Coast.
According to experts, America is only just waking up to the ancient power source lying beneath dozens of states that has the potential to supply as much as 25 percent of the nation's energy needs.
"High prices and climate change are definitely creating a renaissance in geothermal interest, particularly on a state and local level," said Karl Gawell, executive director of the Geothermal Energy Association.
"There really is a tremendous amount going on right now."
As well as Alaska, geothermal projects, which are eligible for tax benefits, are underway in most Western states and across the Gulf Coast from Texas to Florida, he said.
"It's only the tip of the iceberg in terms of what is possible," said Mr Gawell.
"If we really want to go all out for it, we could easily achieve a substantial amount, 20, 25 per cent of US energy needs within a few decades. We're limited more by public policy than the resource - the resource is enormous."
The Bureau of Land Management has just surveyed 11 western states and Alaska for "lands with high potential for renewable geothermal resources".
The study showed around 200 million acres of public land with geothermal potential, Mr Gawell said.
But he estimates 80 per cent of geothermal systems remain undiscovered as they have no tell-tale surface feature such as a hot spring. "We're still just finding the obvious stuff."
Alaska, which is rich in oil and gas, sits on the Pacific Rim of Fire but despite "clear evidence of geothermal resources" the state had shelved its geothermal development "in the 1970s once they hit the major oil streaks", Mr Gawell said.
"It's really only been rediscovered in the past couple of years in part because prices are up."
The biggest challenge to harnessing underground power is working out how to access and tap heat buried deep under earth or rock.
Interest has partly been spurred by the Alaska's successful geothermal venture at Chena Hot Springs, a resort near Fairbanks, which is completely powered by underground energy.
Mr Gawell said that although mentioned this week by Senator Barack Obama, the Democratic presidential candidate, during a speech about alternative energy policies in Nevada, geothermal power had yet to receive enough attention in the national energy debate.
"The problem is it's only being produced in a handful of states. It's well known in those states but it's unknown in others," Mr Gawell said.
Geothermal power is also enjoying a renaissance in Europe, home to the first geothermal steam power plant in Larderello, Italy, which began operating in 1904.
The GEA estimates that the number of countries producing geothermal energy will more than double by 2010 to 46 countries.
Source: http://www.telegraph.co.uk/earth/main.jhtml?xml=/earth/2008/06/26/eavolcano126.xml
