It’s difficult to think of a way to improve on geothermal energy. Geothermal is clean, renewable, accessible and abundant, especially in the U.S., which has already become a global geothermal leader practically without even trying. Well, now a company called GreenFire is putting a little more oomph into the effort. The startup has developing a new technology that uses carbon dioxide – yes, that notorious greenhouse gas – to boost geothermal energy production. The innovation will soon be put to the test at a demonstration project in Arizona.
Geothermal in the U.S.
The impact of future geothermal development in the U.S. could far outweigh the exploitation of solar and wind power, with far-ranging consequences for individual states and the nation as a whole. In terms of national defense, for example, the Department of Defense has estimated that geothermal resources within DoD-owned lands (bases, training grounds, etc.) could provide enough geothermal power to fulfill the energy needs at its facilities, with enough left over to contribute to the national grid. Researchers have also discovered evidence that at least one coal-dependent state, West Virginia, may have enough geothermal reserves to finally shake the coal monkey off its back, enabling it to diversify its economy for a more sustainable future.
GreenFire’s New Geothermal Technology
GreenFire can trace its new geothermal technology contribution to research conducted at the Department of Energy’s Los Alamos and Lawrence Berkeley laboratories. Conventional geothermal energy works by pumping a fluid underground, letting it heat naturally, then extracting energy from the heat. Instead of water, GreenFire will test the use of pressurized carbon dioxide. If the demonstration proves successful, it would be an enormous benefit to the development of geothermal resources in areas where water is scarce.
More Benefits for GreenFire
The company may also be able to demonstrate that its process is more energy efficient than conventional geothermal processes, even accounting for energy needed to compress the carbon dioxide. Since carbon dioxide is lighter than water, less energy would be required to pump it back and forth, which would also help mitigate maintenance and repair issues. As a third benefit, the research so far indicates that some of the carbon dioxide becomes trapped permanently in porous rocks, so the geothermal plant could double as a carbon sequestration facility. To hurry things along, the U.S. Department of Energy has put up $2 million in a cost-share award to get the pilot project up and running.
Geothermal Energy Just Around the Corner
One advantage of geothermal energy compared to, say, nuclear energy, is the speed with which new facilities can go online. One recent example is Utah-based Raser Technologies, which took only six months to start delivering geothermal energy from a newly discovered field in Utah. This has some interesting implications for GreenFire’s demonstration project, which will be located at the St. John’s Dome formation in Arizona. The demo project will use carbon dioxide at the site, trapped naturally from past volcanic activity, but that’s just the beginning.
Coal, Carbon and Geothermal Energy
St. John’s Dome is also near six coal fired power plants that produce about 100 million tons of carbon dioxide annually, so if everything works out, GreenFire will build several commercial scale geothermal plants that use CO2 from the coal facilities. It’s a fast-track way to grab those greenhouse gas emissions while the U.S. continues its long, inevitable transition out of coal.
Image: Raw geothermal energy by veritasnoctis on flickr.com.