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| Former Port of Seattle commissioner Lawrence Molloy says the heat energy underlying parts of Washington could become, in the next few decades, a massive source of renewable energy. Photo by Luke McGuff. |
Washington could have big potential for developing a clean energy source from the heat lying miles below the surface of the earth. Getting to that heat, though, is a problem.
Geothermal energy in parts of the state could, in the future, be enough to supply a very large amount of electricity at low prices, said geothermal reservoir engineer Susan Petty in a brownbag meeting held by the Northwest Energy Coalition Jan. 17. New technology called EGS, or Enhanced Geothermal Systems, will use the heat three or more miles into the earth, going much deeper than conventional geothermal. The initial drilling makes up 75 to 80 percent of the cost connected with using this energy source. But once it’s established, says Petty, EGS will cost half the price of today’s geothermal sources.
Washington is on the edge of the so-called “hot zone” of significantly higher earth temperatures underneath Oregon, Idaho, Nevada, and California. These states have already developed underground windmills, as they are popularly named. Washington has nothing developed, permitted, or sited. Engineers see big potential in the eastern part of the state for the next generation of geothermal power plants. But local land-use law doesn’t acknowledge the technology, yet.
“Washington is not ready to handle applications [for geothermal power plants]”, says engineer Lawrence Molloy, a former commissioner at the Port of Seattle who has worked on clean energy solutions around the Pacific Rim for more than a decade. “It is as in the 1990s with the wind farms.”
The technology used today is taking advantage of the heat less than two miles into the earth. It generates enough power to make the United States the largest producer of geothermal energy worldwide. Many plants have been running for a long time in areas near hot springs and geysers in California and Nevada.
Drilling deeper could boost U.S. capacity, making more potential sites eligible to explore. The new technology means plants do not need to be close to hot springs or natural faults and fractures, thereby not conflicting with interests of national parks, rural Indian reservations, or wilderness areas. The increased capacity does not mean a larger footprint, since the plant size is the same; only the depth of the drilling is increased, explained Petty. Geothermal engineers drill more than three miles down into dry, hot rock. By forcing cold water into the rock, a man-made hot water reservoir is created. Injection wells are then drilled to circulate water in a closed system being heated up by the reservoir. The steam runs electric turbines and then, when it condenses back into water, is re-injected into the reservoir.
“The technology is feasible and the best resources are economical already today”, said Petty at the Jan. 17 meeting. “By 2050, we could generate 50,000 megawatts of EGS power.”
By contrast, the Grand Coulee Dam on the Columbia River produces an average of 4,000 megawatts on a cold winter day, says Lynne Brougher, the dam’s public affairs officer. That’s enough to power 3.5 million homes on the West coast. Fifty thousand megawatts could power 43 million homes.
According to Petty, EGS energy could be developed in the Pacific Northwest in the next five to eight years, probably in Oregon first. Once it gets going, it will add 10 to 15 percent annually in power supply. It takes about three years to complete a facility.
The benefits are very much the same as with conventional geothermal, said Petty; it’s reliable, leaves a small footprint, poses almost no risk to finite natural resources, and can be scaled to local needs.
An extra benefit is geothermal’s potential to create jobs in southeastern Washington, an area of high unemployment with known geothermal potential.
The system does have some environmental needs: about 40 million gallons of water, more than half the contents of Lake Union, are injected into the ground. But the water does not need to be clean, and only about two percent is lost annually, explained Petty. Experts in the field say that the low amounts of carbon dioxide generated could be re-injected into the reservoir.
EGS could make a huge contribution to the domestic energy supply. The question on clean-energy advocates’ minds, as Molloy framed it in the Jan. 17 meeting, is “How do we, as a state, move forward?” |
