Geothermal developers from AltaRock Energy, a Washington state-based company, have been working on creating geothermal reservoirs with their own technology. They have recently made three such reservoirs from a single well, which means there is a greater chance a commercial geothermal plant can be built because with more reservoirs there is greater flow and energy output for each well. With human-made reservoirs expanding the energy output, the overall cost of constructing a geothermal plant could be reduced by 50%.
These reservoirs are also called stimulated zones or enhanced geothermal systems, and located at the Newberry Enhanced Geothermal System (EGS) Demonstration site, which is near an ancient volcano in Oregon. They are created by injecting cold water into hot, low permeability rock to amplify fractures there, which then allows the surface hot water to leak out and fill the human-made reservoirs. (The Department of Energy has contributed over $20 million to their research.)
The potential costs savings results from the ability to create multiple hot water reservoirs from one well or single site. Alta Rock has made Thermally Degradable Zonal Isolation Materials (TZIM) to help create these multiple zones. A biodegradable polymer was used at the Newberry site in a process that was implemented several times. It is possible to do more than three stimulation rounds at one site for reservoir creation.
If you would like to follow the Newberry project updates, Alta Rock has been publishing a blog.
Geothermal is believed to have large potential because it has a smaller environmental footprint and produces clean energy 24/7, whereas solar and wind power are intermittent sources. Typically, one may think of Iceland as being nearly synonymous with geothermal power, but there is no reason it can’t be developed all over the world, if there are sufficient natural resources for it.
