, the philanthropic wing of Google, has announced a $10 million investment in a renewable energy technology that's powered by hot rocks several miles beneath the earth's surface. The technology, called Enhanced Geothermal Systems (EGS), differs from traditional geothermal energy that relies on finding natural pockets of hot water and steam. Instead,
EGS fractures the hot rock, circulates water in its system, and uses the steam created from the process to create electricity in a turbine [Cleantechnica].
The system could augment less reliable renewable energy sources like solar and wind power, which don't generate steady amounts of energy. Google executive Dan Reicher says EGS would be very dependable, and could be revolutionary.
"It's 24-7, it's potentially developable all over the country, all over the world, and for all that we really do think it could be the 'killer app' of the energy world" [New Scientist].
The move is part of Google's effort to pump hundreds of millions of dollars into green energy sources, starting with solar thermal, high-altitude wind power and now, geothermal energy [Reuters].
The company hopes to use its private investments to develop renewable energy sources that are cheaper than coal. Traditional geothermal plants have been used for almost a century in places where hot water and steam lie very close to the Earth's surface, like Iceland and New Zealand. The EGS system requires deeper drilling, but is less limited by geology.
Since many of the Western U.S. states have heated rock within the drilling range of two to three miles, [AltaRock CEO Don] O'Shei also said the wells could be located nearly anywhere [Seattle Post-Intelligencer].
Check out the full story on geothermal's promise and pitfalls in the recent DISCOVER investigation, "The Great Forgotten Clean-Energy Source: Geothermal."