Raser rapidly deploys geothermal power at its Thermo plant in Utah

Raser Technologies, Inc. (NYSE:RZ) announced on December 30, 2008 that it has completed the initial commissioning process of its 10-MW Thermo geothermal plant at Beaver County, Utah. This will be the company’s first commercial scale power plant.

What makes this significant to the geothermal community worldwide is that the facility was built in only six months, compared to the normal five to seven years’ time using traditional field development and plant construction technology. Raser was able to achieve this breath-taking speed by using 50 off-the-shelf power generation units (the Model 280 PureCycle System) each capable of producing 280 kW of power from United Technologies Corp. (NYSE:UTX). Theoretically, the plant can generate up to 14 MW of power; but about 3 MW are used to run the pumps and other field equipment.

Each of these is actually an organic Rankine cycle (ORC), or binary cycle unit, which uses as organic compound as its secondary fluid. This means that hot geothermal water is used to boil this fluid—which turns the turbines—rather that the water used directly.

The scheme allows the use of very low temperature geothermal resources which hitherto are considered unusable for power generation. This expands significantly the geothermal resources available for power production not only in the U.S. but throughout the world.

Raser makes the impression that it is deploying advanced technology to exploit low temperature geothermal fields—but in fact, ORC has become a standard technology for these types of resources. Turboden of Italy and other turbine manufacturers, have deployed ORC units for low temperature geothermal development in countries such as Italy, Germany, Austria and Switzerland in recent years. These units are also ideal for power generation from waste heat.

What is somewhat new is the use of the refrigerant R-145fa, or 1,1,1,3,3-pentafluoropropane, as the working fluid and the number of units simultaneously deployed. Because the units are factory assembled in modular units, these can be easily transported and installed at the site.

R-145fa, a refrigerant with zero carbon emission and a global warming potential of 950 kg carbon dioxide (low compared to most refrigerants) has become a fluid of choice for most modern refrigeration systems and recently as secondary fluid in binary cycles even if the price is still somewhat high. It has a boiling point of only 15.3 C at atmospheric conditions which allows geothermal water at 91-150 C to be tapped for power generation.

The commissioning is progressing nicely, according to Raser, and should be completed in the next few weeks. During the commissioning, the power generated is taken up by Rocky Mountain Power, a division of PacifiCorp. Under regular operation the power will be dispatched to Anaheim, California under a signed power purchase agreement.

The geothermal world and investors in renewable energy would be watching keenly the interesting development at Beaver County—the Philippines included.

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UPDATE, January 16, 2009: Raser technologies reports January 15 that it expects the local utility which will take up its output will complete the installation of SCADA equipment soon. This will allow Thermo (the geothermal plant) to increase its generation to 3 MW it can send to the grid starting next week. Raser believes that their output can be transmitted to Anaheim within the next few weeks.