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Hudson Ranch I first new geothermal plant to go online in the Salton Sea in 20 years

Hudson Ranch I geothermal power plant, March 2012, Salton Sea, California/ U.S. (source: EnergySource)
Alexander Richter 6 Mar 2012

U.S. geothermal developer EnergySource announces electrical grid synchronization of the newly completed Hudson Ranch I geothermal power plant, well field test results and operation start of the plant later this month.

In exciting news earlier last week, U.S. based geothermal development firm EnergySource LLC announced both “the successful electrical grid synchronization of its newly completed Hudson Ranch I geothermal power plant, as well as outstanding well field test results”.

This is a great milestone for a project and company that I have been following quite closely over the years. So congratulations to the team around EnergySource and the affiliated companies. In a follow up post I will provide more details about the involvement of New Zealand’s Mighty River Power in the project.

The Hudson Ranch I geothermal power plant “is generating at its designed 49.9 MW capacity in one of the largest and highest temperature geothermal resources in North America — the Salton Sea field, in Imperial County, California. The plant is completing its start-up testing and initial delivery of power to the grid, with commercial operation expected later this month.

Hudson Ranch I is the first new geothermal plant constructed in the well-proven Salton Sea field in more than 20 years. The Salton Sea field is characterized as a very hot and extremely permeable liquid dominated resource, ideal for power generation, but with the challenge of high minerals concentration, making energy project development in this resource a very specialized endeavor. Construction of the $400 million plant began in May 2010.

“Tests to date on the wells and resource have confirmed the company’s belief that the Salton Sea resource is very hot, high in total dissolved solids and highly prolific,” said John Featherstone, senior vice president of engineering and operations at EnergySource. “The well tests have exceeded our expectations.”

Hudson Ranch I drilled three production wells and four injection wells to supply the power plant with steam and recharge the reservoir with cooled geothermal brine. The combined productivity of the production wells is approximately two-times plant requirements, with similar results from the injection wells. Specifically, Hudson Ranch I’s production well 13-1 can produce greater than 15 MW, while production wells 13-2 and 13-3 can each produce greater than 40 MW, making the latter two wells among the largest producers in the world and giving the generating plant outstanding operational flexibility. The result of this drilling success is that the plant is capable of normal operation on two of its three production wells, and on two of its four injections wells, an unprecedented outcome, Featherstone said.

The test results indicate that these wells are “extremely prolific” according to Dr. Subir Sanyal, president and manager of reservoir engineering services at GeothermEx, an independent geothermal resource consultant working for Hudson Ranch I’s bank group. “The Salton Sea geothermal resource is robust, with 326 MW in 10 existing projects currently operating at a capacity factor substantially greater than 90%, with a development potential of 1,400 MW or more,” Sanyal said.

David Barrick, managing director of ING Capital, one of the banks financing project construction, said, “These well field test results confirmed our confidence in the project’s Salton Sea geothermal resource and support our continuing interest in lending to geothermal projects such as Hudson Ranch I.”

“EnergySource has attracted a development and operations team led by John Featherstone with many decades of experience designing and operating power plants in this unique resource,” said Dave Watson, president and CEO of EnergySource. “With this team and so much available capacity in this resource, we have a development pipeline of new geothermal projects for the coming decade that will help California and Southwestern utilities meet their state-mandated renewable energy requirements.”

Hudson Ranch I will sell all of its energy, capacity and environmental attributes to Salt River Project (“SRP”), a municipal power and irrigation district in Tempe, Arizona, for a term of 30 years. In late 2011, SRP announced that a second Power Purchase Agreement was executed to purchase all of the output of EnergySource’s next project, Hudson Ranch II, also a 49.9 MW plant.

Hudson Ranch I created more than 200 jobs during construction and will have more than 55 employed full time during operations.

Source: Company press release via Marketwatch