“Enhanced geothermal engineering” is where you shoot hundreds of thousands of gallons deep into the ground, let the heat and pressure down there spike its temperature and then bring it back up as super-heated water or steam to provide power. You basically have yourself a big underground teakettle that makes clean energy. There’s one huge drawback, though.
In October, at the Deschutes National Forest in central Oregon, a team of scientists and engineers began pumping 11 million gallons of water underground, right near the caldera of the famed Newberry Volcano. The Northwest weather was a cool 50 degrees most days, about the same temperature as the water the engineers drove, up to 375 gallons a minute, 10,000 feet into the ground. There, deep in the earth’s crust, the temperature reaches more than 600 degrees. That’s what the engineers were pumping for: If everything goes according to plan, a company called AltaRock Energy will suck the super-heated water from underground and use it to spin turbines and juice the area with renewable power.
Over the next two months, the engineers would keep pumping the water, as the weather started to turn. Snow gathered itself up tree trunks and the engineers' equipment, eventually forcing them to lower ground. All the while, the team listened for rumblings from deep underground. The water pushed against fractures deep in the earth at 2,400 pounds per square inch, more pressure than an alligator's bite, expanding natural cracks in the rock until a network of watery tunnels formed below ground. Not long after starting, the team picked up the first earthquake, then, over the course of their experiment, picked up 219 more. [Popular Science]