For $1 billion over the next 40 years, the U.S. could develop 100 gigawatts (a gigawatt equals one billion watts) of electricity generation that emits no air pollution and pumps out power to the grid even more reliably than coal-fired power plants, according to scientists at the Massachusetts Institute of Technology. Now—the charitable wing of the search engine giant—has chipped in nearly $11 million for this renewable resource: so-called geothermal power, or tapping the Earth's heat to make electricity.

That makes the largest funder of enhanced geothermal research in the country, outspending the U.S. government. The Australian government has pledged $43.5 million for such projects and already has several in the works, as do Europe and Japan.

But no such advanced geothermal plants are online in the U.S. at present, and may not be for many years to come. No one has successfully completed all the steps—or demonstrated all the technologies—needed to drill deep beneath the surface, fracture the rock, pump water or other fluids down into the ground to absorb the interior heat, and then bring it to the surface. Once topside, the hot water can be used to make steam to turn turbines and produce electricity.

"We think we can open up fractures, that's not a problem. You can certainly drill wells and directionally. You can convert the hot water into steam," says chemical engineer Jefferson Tester of M.I.T., who co-authored a report detailing the promise of so-called enhanced geothermal systems (EGS). "It gets down to good well connectivity."

"The fireball that sits within the Earth is a resource," said geothermal evangelist Ólafur Ragnar Grímsson, president of Iceland, a country now largely heated and powered by the Earth's heat, at the Geothermal Development and Finance Workshop on July 23 in New York City. "We walk on it, we sleep on it, we work on it; the question is: How do we harness it?" hopes that Sausalito, Calif.–based AltaRock Energy can begin to develop the answer with the $6.25 million it is investing in the company. The challenge is steep for such power-producing technology. That is because rather than relying on areas where Earth's heat comes close to the surface—such as The Geysers geothermal formation in California and similar resources that provide nearly 3,000 megawatts of power at present in the U.S.—AltaRock and companies like it would actually drill deep into the Earth, fracture the subterranean rock to create a reservoir, and then pump fluid through the repository to capture the surrounding geothermal heat.

"The geology is very important," says Paul Thomsen, public policy manager for conventional geothermal outfit, Ormat Technologies in Reno, Nev. "The deeper you drill, the more expensive it is. Geology brings magma and heat closer to the surface in the western U.S. If we could drill deeper, then we could move east."

Mastering said drilling is why also invested $4 million into Potter Drilling, a Redwood City, Calif., enterprise built from EGS drilling work done at Los Alamos National Laboratory in New Mexico during the last oil crisis in the 1970s. As it stands, the oil and gas industry routinely drills wells of more than 18,000 feet—nearly 3.5 miles, or 5.5 kilometers—which would "essentially unlock the entire country" to produce geothermal power, said Dan Reicher, director for climate change and energy initiatives at and former assistant secretary of energy for energy efficiency and renewable energy at the U.S. Department of Energy, at the same conference.

But that also means that would-be geothermal companies are competing with the flush oil and gas industry for drilling rigs. "There are roughly 1,900 drilling rigs in the U.S.," added Lou Capuano of ThermaSource, another geothermal drilling outfit, at the conference. "Seven, maybe up to 11 now, are geothermal."

And, even if the rigs become available, it remains unclear just exactly what is lurking where under the surface. Maps for geothermal potential have not been updated since 1974 despite more than a million new oil and gas wells in the interim offering more data. So is also giving $489,521 to Southern Methodist University's Geothermal Laboratory to update the resource maps.

"EGS is not for tomorrow," adds Lucien Bronicki, Ormat's co-founder and chief technology officer. "You have to reduce the cost of drilling to be able to go deep. You have to improve the efficiency of the pumps so you don't lose too much electricity pumping water around."

But for Google, one of the world's largest consumers of energy for its endlessly multiplying data centers, access to a googol's worth of clean energy is quite appealing. "EGS is a very exciting opportunity," Reichert adds. "We have a long way to go to bring it to commercial reality."