Thermoelectric Generators in a Geothermal Field

This is an R&D project which will build and test a new field-scale thermoelectric generator (TEG) at our Bottle Rock Power geothermal facility near Cobb, California. TEGs produce electrical energy when a strong enough temperature difference exists across the generator (a phenomenon known as the Seebeck effect). This will be the first TEG developed specifically to generate electricity from a geothermal resource with the goal of making renewable geothermal electricity more competitive in the marketplace. This project will not only prove the feasibility of using TEG materials with a geothermal resource but also develop how this technology can be installed in an operating field. This project is supported by a generous grant from the California Energy Commission’s Electric Program Investment Charge (EPIC) program.

This work is needed to bring geothermal-TEG technologies to a pre-commercial stage. This project will support the future design of a demonstration-scale project for appraisal of operational and performance characteristics and financial risks of utility-scale geothermal-TEG projects. This project aims to help expand development of untapped and localized geothermal resources. Growth of the geothermal industry has been held back by the need for large and costly power plants and large scale infrastructure to produce geothermal electricity on an economic scale. Typically, a geothermal project cannot produce electricity economically at a scale less than 5 MW and there is a very large economy of scale for projects above 30 MW in size. TEG technologies, however, have the potential to produce geothermal electricity without all the infrastructure – turbines, steam piping, etc. – thus making small scale production and geothermally-source micro power grids both practicable and affordable. Small (<5 MW) geothermal projects could provide consumers with the same distributed power flexibility provided by solar and wind production with the additional benefit of being a more reliable base load source of electricity.

Supporting Bottle Rock operations will help California to meet its quota for renewable energy resources. This project would allow additional opportunities for geothermal facility development, as well as residential and commercial development, providing more jobs and homes for Californians.