The geothermal industry put out its annual report card this week. There are 150 geothermal projects in the works nationwide; 16 of them are in Oregon. That puts Oregon third in the nation in terms of development behind Nevada and California. (Idaho is fifth with 11 pending projects.)
One of the unique projects in Oregon is AltaRock Energy’s Newberry Volcano enhanced geothermal demonstration project, which was just approved to move forward yesterday. AltaRock President Susan Petty said her company is the only one trying for “enhanced geothermal” energy in the U.S.
The enhanced part is needed because the Newberry Volcano site has only one of two key elements of generating geothermal energy. It’s got the hot rocks 10,000 feet underground. But it doesn’t have water.
So, AltaRock is going to inject pressurized water underground, break open natural fractures in the rock – inducing mini earthquakes in the process – and create underground water storage. The hot rock within the volcano will heat the water and create steam that can move a turbine and generate electricity. (Vince Patton’s Oregon Field Guide episode above illustrates the concept well.)
How much electricity is the question AltaRock is looking to answer. That’s what the first two years of the project will be testing for. However, the tests will only allow the company to gauge power-generating potential. They won’t produce any actual power.
Petty calls the injection process “stimulation”, and she said you can watch the mini-earthquakes it creates online through the Lawrence Berkeley National Lab, which will be mapping them here.
The Newberry site will be a test of enhanced geothermal potential, and AltaRock is aiming for 10 megawatts of power from two wells in its initial testing.
“That’s very small,” said Perry. “But it would tell you if you had potential to get the energy per well that would make for an economic project.”
There are two commercial plants in Europe making power from enhanced geothermal technology, Perry said. But they’re producing 1.5 megawatts and 3 megawatts per well.
“We really feel it’s important to get higher production rates,” said Perry. “In Europe it makes more sense to produce power with this method even with lower rates of flow because they have incentives.”
In the U.S., renewable energy has to compete more directly with power produced from cheap natural gas.
Creating more mini quakes to make more room for water to flow underground is the way AltaRock plans to get more power per well.
But Perry said that strategy has limits.
“You can’t just push water through,” she said. “You have to push it through without cooling the rock down. We could push more water through cut cool things down too quickly.”