Neal Hot Springs geothermal plant ready to switch on

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The modular geothermal plant at Neal Hot Springs is close to coming online, adding a dramatic boost to Oregon's geothermal energy portfolio. 

Neal Hot Springs, the 22-megawatt geothermal facility in Malheur County in southeast Oregon, is nearing mechanical completion and set to roll turbines.

The $140-million facility has been in development by Boise, Idaho-based U.S. Geothermal Inc. (NYSE: HTM) since it acquired additional mineral rights there in June 2010. The original rights were acquired in 2007. The facility is located about 90 miles northwest of Boise.

Largely supported by a $96.8 million loan guarantee from the U.S. Department of Energy, the project was built in three 7.3-megawatt modules, two of which are mechanically complete and ready to start up in three to four weeks.

Neal Hot Springs has been closely watched in the geothermal industry for the advances it has made in geothermal technology. The project uses three areas of innovation, according to U.S. Geothermal CEO Daniel Kunz.

The new features include:

• The working fluid used at Neal Hot Springs is a non-flammable, non-toxic refrigerant compound instead of traditional isopentane. The fluid captures the geothermal heat that comes out of the ground and drives the turbines while the natural geothermal fluid is pumped back underground.

• The project was built in modules, with the skids constructed in a factory, then shipped to the site for assembly.

• The cooling tower employs larger scale fans instead of traditional small ones.

“These three areas of innovation have already been employed at other sites around the West as a result of Neal’s use of them,” Kunz said in an email.

Neal Hot Springs is also among a relatively small number of large-scale geothermal plants in the United States and the first such plant in Malheur County. It will add a dramatic boost to Oregon's installed capacity of geothermal energy, which sat at less than 1 megawatt at the end of 2011.