February 25, 2013

Scientific American

New Geothermal Data System Could Open Up Clean-Energy Reserves

Forgotten and filed away decades ago, millions of documents on geothermal research are now helping scientists to make harvesting the Earth’s energy affordable

Geologic data does not come cheap, especially when you are using it to build a multimillion-dollar geothermal power plant. Just ask Susan Petty, president and chief technology officer at AltaRock Energy. Her company is part of a $43.8-million pilot project to tap thermal energy from Oregon's Newberry Volcano. Engineers are injecting water deep underground to fracture superheated rocks and create a geothermal reservoir. Their eventual goal is to recirculate pressurized steam back to the surface to test a new kind of technology called an enhanced geothermal system (EGS). Unlike conventional power power that rely on near-surface hydrothermal systems like springs and geysers, EGS can draw energy up to depths of three to five kilometers. Over the next 50 years, the U.S. Geological Survey estimates, EGS power plants could produce 100 gigawatts of economically viable geothermal energy, an amount equivalent to about 10 percent of the country's current electrical capacity.

Yet geothermal wells need to be drilled in the right place. Without data on the distribution and quantity of geothermal energy in the upper part of the earth's crust or a volcano as a reference point, wells may not produce much energy at all. To date, two to five out of every 10 geothermal wells prospected end up dry. Petty says that, in terms of the available exploration data, the geothermal industry is in the same place oil and gas companies were during the early 1900s. Wells cost between $2 million and $5 million, meaning geothermal investors risk losing millions on poor odds, Petty says. “The risk involved in geothermal prospecting sets the industry apart from other renewables.”

The risky nature of the business could soon change, however.

To read the full article, visit: http://www.scientificamerican.com/article.cfm?id=new-geothermal-data-system

By William Ferguson