October 1, 2017.
Traditional choices for geothermal power plant implementation are areas that have a high temperature and flowing water below the surface. Wells can be drilled down into the rock to harness the steam produced by the hot water and spin a turbine to produce electricity. The problem is that only about 10 percent of Earth’s land area has water circulating under the surface. Only a portion of those areas are hot enough to produce the necessary amount of steam. There are three different types of geothermal power plants that can be used depending on the situation. Chena Geothermal Area, located in Alaska, is an example of a low temperature geothermal resource that utilizes a binary system to produce energy.
One way to assess specifics about a geothermal resource is by using GeoRePORT. This is a new methodology created by the U.S. Department of Energy’s Geothermal Technologies Office that is striving to make a consistent and comprehensive standard for reporting geothermal data. GeoRePORT is a spreadsheet that asks experts to input specific information about their geothermal site and it assigns a grade based on what they choose. The grades are on an A through E scale, but those do not necessarily determine the success of the resource, meaning a resource with mostly A’s is not better than a resource with mostly E’s. Different projects need different grades to be successful depending on their goals.
This case study proves that high resource grades are not necessary for the success of a geothermal resource.
National Renewable Energy Laboratory (NREL)
This material is based upon work supported by the National Science Foundation through the Robert Noyce Teacher Scholarship Program under Grant # 1418852. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. The research was also made possible by the California State University STEM Teacher and Researcher Program, in partnership with Chevron (www.chevron.com), the National Marine Sanctuary Foundation (www.marinesanctuary.org) and National Renewable Energy Laboratory.