EPRI on Renewable Energy: Single Well Geothermal

Enhanced geothermal without the earthquakes

Eric Wesoff January 13, 2010

Eric Wesoff

Editor-at-Large
Greentech Media

Eric Wesoff is Editor-at-Large at Greentech Media. Prior to joining GTM, Eric Wesoff founded Sage Marketing Partners in 2000 to provide sales and marketing-consulting services to venture-capital firms and their portfolio companies in the alternative energy and telecommunications sectors. Mr. Wesoff has become a well-known, respected authority and speaker in these fields.

His expertise covers solar power, fuel cells, biofuels and advanced batteries. His strengths are in market research and analysis, business development and due diligence for investors. He frequently consults for energy startups and Silicon Valley's premier venture capitalists.

EPRI Renewable Energy Part One

Geothermal energy already provides a small portion of California's energy but that's because California is the Saudi Arabia of geothermal resources. GTM did a quick rundown of geothermal power available here. The Geysers is one of California's geothermal prizes. Luis Cerezo of EPRI spoke on the topic of geothermal on Wednesday afternoon.

Enhanced geothermal is a technology that looks to coax more energy from the earth in sites that are not exactly low-hanging geothermal fruit.

Current deployments of EGS require two wells and a large water source. They also have garnered some spectacularly bad press of late as some EGS deployments in Germany and Switzerland have instigated serious earthquakes.

The Electric Power Research Institute (EPRI) has a project investigating a new type of Enhanced Geothermal Systems (EGS) - single well geothermal. Single Well Geothermal potentially resolves many of the problems with conventional EGS - lower environmental impact, less ground water contamination, and mercifully less seismic events.

Another advantage to Single Well Geothermal is that there are over 4,000 abandoned bore holes from the oil and industry that can be used for the geothermal industry and the single well architecture.

Here's an illustration of GTherm's single well closed loop system with a heat exchanger that uses a high thermal conductivity material (like cement) and a binary cycle closed system.