AMEC wins engineering contract for geothermal plant

AMEC has been awarded a $6.8m (£4.5m) contract by Energysource to provide engineering services for a 49MW, $350m geothermal power generating facility at Salton Sea, California.

The Hudson Ranch I project, located in Imperial County, is the first standalone flash geothermal plant to be built at the Salton Sea geothermal site in recent years. Work on the project has begun and is expected to be complete by 2012. AMEC will be responsible for design, engineering, training and assistance during the construction and start-up phase.

The geothermal power plant will produce electricity from naturally occurring geothermal steam stored in superheated water reservoirs thousands of feet beneath the Earth’s surface.

The facility will be a triple-flash plant using high-temperature Crystalliser Reactor Clarifier (CRC) technology to process the geothermal brine and steam from the Salton Sea production wells.

Crystalliser-reactor clarifiers are used to turn the superheated fluids into steam while removing solids from it. The fluid is then used to drive the turbine that generates electricity.

Triple-flash plant or a combined single- and double-flash plant is often used when the resource temperature is equal to or greater than 240°C. In this case, the waste brine from the first two units is subjected to two more flashes, resulting in two additional low-pressure steam flows.

The plant will include a turbine generator, cooling tower, wellhead separators, crystalliser, water tanks, primary and secondary clarifier tanks, control building, office buildings, substation, pipelines and supports, various ancillary structures and associated internal roadways.

The plant will take 21 months to build and will employ 35 full-time employees when complete. Once the project becomes operational, Salt River Project (SRP), a major southwestern utility, will purchase the power generated.