Ormat to add new plant to Mammoth geothermal power complex
Representatives from Ormat, owners of Mammoth Pacific’s geothermal power plant, briefed Mono County’s Board of Supervisors on Tuesday about plans to begin building a fourth power plant that will essentially double the complex’s current power production capability.
Charlene Wardlow, Director of Business Development for Reno-based Ormat, which owns the Casa Diablo geothermal power facility located off U.S. 395 just below the Hwy 203 interchange, said the new Casa Diablo 4 (CD-4) plant will, when completed, yield 33 megawatts (MW) by early 2013, supplying enough electricity for approximately 25,000 people.
The plant will be able to tap an expanded geothermal well field that’s part of a magma parcel leased from Los Angeles Department of Water and Power (LADWP). In addition to pipelines to bring geothermal “brine” to and from the injection wells, CD-4 will also augment a standard air-cooled system with a new, untried feature: water-cooling for some of the hotter times of year. Wardlow said the water-cooled mode would siphon off a certain amount of MCWD-supplied water to lower the condenser temperatures and dissipate excess heat.
Casa Diablo’s current three-plant complex currently produces 29 MW, all of which is sold to Southern California Edison, which is in turn used by, among others, many customers in the Eastern Sierra region. Ormat now owns 100 percent of Casa Diablo following an Aug. 2 agreement to purchase Constellation Energy’s 50% stake in the partnership for $72.5 million. The sale means Ormat also owns Casa Diablo’s land, plants and associated equipment, and (perhaps more important) the development rights to more than 10,000 acres federal land.
In addition to adding a new plant, Ormat also has plans to “repower” (or replace) its G-1 plant at Casa Diablo with a new one that will be based around a state-of-the-art Ormat Energy Converter (OEC). G-1, which produces 10 MW, began operation in 1984. The new generation OEC is more efficient, considerably lessening if not entirely eliminating hydrocarbon emissions due to leakage.
More exploration for new geothermal wells is also in the offing. Last month, Mammoth Pacific began the process of drilling two wells, part of the CD-4 well field, approximately a half-mile north of Mammoth Lakes near Shady Rest Park. (Permitting was completed in 2005 for the land, which is managed by the U.S. Forest Service. Bureau of Land Management processes the leases and permits.) Up to 16 wells in 18 locations will be drilled during the life of the project development.
Don’t think British Petroleum drilling rigs. These well pads and rigs disturb a relatively small area, roughly 350 feet by 300 feet, and are only 178 feet tall. Completion of the drilling near Shady Rest is expected in about one month, Wardlow said. The rigs employ a 100-person support staff.
Mammoth is only one part of a large, 475-million acre swath of 11 western states with geothermal potential, but has taken a historical lead role in advancing the virtually infinite renewable resource. “There are hot springs and fumeroles in Eastern Sierra that, along with earthquakes and active volcanoes, produce great amounts of resources,” Wardlow explained. “The old technology required 450-degree temperatures to generate power, but Mammoth helped pioneer using lower temperatures in the 300-350 degree range. You need three things for geothermal: water, a heat source and permeability. Casa Diablo has all of those things.”
Mammoth Pacific’s current contract calls for selling power “on the grid” to SCE, but Wardlow said no contracts exist as yet for CD-4. Prices are an issue, she indicated. “Everyone says they want geothermal, but with fossil fuel prices declining, the CPUC average price has dropped from $120 per MW hour, down into the $80s.”
With 30-40% of the nation’s earthquake activity in California, and a spate of shakers recently felt in the area, is Ormat concerned about how that will affect its drilling? Wardlow said the company is always concerned about quakes, but has learned to deal with them as something of an occupational hazard, given the volatile seismic nature of the regions in which it typically works. “We just roll along with them,” she said.
Supervisors had little in the way of questions or comments, but they did kick around the idea of applying geothermal for use by Mammoth Brewing Company (MBC), should it win the rights to set up its new brewery facility on the old Sheriff Substation property on Substation Road. (MBC and Mammoth Dog Teams have both put in bids for a new lease on the property, and may be co-lessees if discussions with the two parties go well.) MBC’s Joyce Turner indicated the company would be thrilled to have geothermal as part of the brewing process. “We’d be one of only two microbreweries in the country to have it,” she pointed out.
Will the new CD-4 plant be a player in Mammoth’s progression toward one day enacting a geothermal heating district? Possibly. Wardlow said it’s hard to say definitively at this point. Ormat’s engineers have yet to study whether the plant could send enough heat up to Mammoth and still meet the company’s contracted energy output requirements to SCE. She did, however, say that it’s on their “to do” list, and said that Ormat remains in regular communication with High Sierra Energy Foundation’s Rick Phelps.
Wardlow’s resume boasts more than 30 years in the geothermal energy business. Ormat has more than 45 years experience in environmentally oriented power generation, specializing in geothermal and recovered energy technology and delivery. The publicly-traded Ormat has a worldwide payroll of 1,000 employees, holds 75 patents, and has designed power plants, in Nevada (the Steamboat complex is currently drilling new exploratory wells off Hwy 50) and Alaska (at Mount Spurr, a volcano in the Aleutian Volcanic Arc), as well as in Nicaragua, Kenya and parts of Europe.
