The Green Optimistic

America can kick its addiction to fossil fuels by drilling more wells, says a panel of experts at the Massachusetts Institute of Technology. Not for oil, but to tap Earth’s heat.

Converting geothermal heat into electricity by pouring water onto hot rocks underground and using the steam to turn turbines is arguably the most promising - and renewable - source of “green” energy on the planet. So concludes the MIT experts’ report, released on Monday, which examines what geothermal energy could do for the US in the 21st century.

The 18-member panel calculated that there is more than enough extractable hydrothermal energy available to generate the entire 27 trillion kilowatt-hours of energy consumed in the US in 2005. In fact, a conservative estimate of the energy extractable from the hot rocks less than 10 kilometres beneath American soil suggests that this almost completely untapped energy resource could support US energy consumption, at its current clip, for more than two millennia to come.

Developing a new generation of geothermal plants is thus a top priority for tackling global warming, the panel says. “By any kind of calculation, this is an extremely large resource that is technically accessible to us right now,” says the study’s lead author, Jefferson Tester. “It doesn’t require new technology to get access to it. And there’s never going to be a limitation on our ability to expand this technology because of limits of the resource.”
From issue 2588 of New Scientist magazine, 27 January 2007, page 4