Geothermal plant cost potentially cut by 50%

ReNew Economy has a post on efforts by AltaRock to reduce the cost of enhanced geothermal power generation by shifting to a single well model - Geothermal plant cost potentially cut by 50%.

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 per cent.

“The purpose of the Newberry EGS project is to demonstrate AltaRock’s tne technology designed to lower the cost of EGS, and thus allow economic extraction of heat from the earth in locations where high temperatures can be reached by conventional drilling techniques,” said Susan Petty, founder and president of AltaRock. (Source: Fort Mill Times)

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.