Desert-energy-046-310x175 Geothermal plant at the Salton Sea

The geothermal resource around the Salton Sea is the nation’s best. The potential there is several times that of the Geyers steam system where  recycled water is injected and pumped out using solar power. In the Salton Sea region, there is 2  – 2.5 GW of geothermal capacity, about equivalent to the San Onofre nuclear station. And it’s all hot water 400 – 500 degrees. We visit two plants.

There’s a reason that this is a hotbed for geothermal in the Salton Trough. Geothermal resources are heated by the Earth’s mantle. Eighty 80 miles east of San Diego, the area is “seismically rich,” with active spreading and attendant, plate-juncture plutonism. The  average geothermal well depth is 1,750 meters.

Brand new, proud of it. The Hudson Ranch 1 Plant (renamed the Featherstone plant), is owned and operated by EnergySource, an LLC “at the forefront of developing, constructing, operating and owning geothermal plants in the resource-rich Imperial Valley” They’re in their second year, up and running with 95% availability, and generating 49.9 MW of geothermal (nearly carbon-free) baseload, renewable power. (There are limited carbon dioxide gas releases during the geothermal extraction.) We roll into the facility, the first geothermal plant built in the region in two decades. It features two of the largest production wells in the world. From the turbine deck of the plant we can see several other geothermal plants a few miles away.

This new plant, ironically, is selling its capacity under a 30-year contract to the Salt River Project in Tempe, Arizona. So much for using locally grown power in the region! Its extraction wells draw hot water from below, pressuring turbines to generate power. Every day 8- 9 tons of sludge is removed in the process, two to three large tractor trailer semis truck it off to dumps far away. The “clarified” water is re-injected outside of the generation field.

This new plant also features an innovative partnership with Simbol Materials, a company that has found significant quantities of lithium, zinc, and manganese — key battery ingredients — in the brine water extracted for geothermal. (Lithium carbonate is used as a electrolyte.) These materials are crucial to the ramping up production of electric vehicles. (Currently China produced 95% of the global rare earth mineral production. Simbol takes the plant’s effluent and extract these precious materials. Given their quantities and demand, this may be the basis for a new industry in the region.

We leave the plant and take a dirt road following a canal which seems very insufficient for the bus. But there is no turning back. After a half mile or so we cross a small bridge and return to “a major arterial.” Shortly we pull into the driveway of another geothermal plant, this on owned by CE Generation LLC, 50% owned by MidAmerican Energy Holdings. It’s operated by CalEnergy.

“Rust never sleeps,” says my bud Pat. This plant shows its age. It’s one of ten plants built in the area from 1982 – 2000. But apparently it’s going strong; no mention of an overhaul of its systems needed. In this control room, operators are keeping an eye on multiple plants. The plants have a net capacity of 327 MW. Eight of the plants are under contract with Southern California Edison.

Later we drive through the town of Calipatria, 146 feet below sea level. As a tribute to the pharmacist’s wife, killed in a tragic car accident, the town erected a flag pole of the same height. To this day old Glory flies above sea level in Calipatria. By noon the temperature climbs above 90. We swelter at each stop on tour and in the heat. The bus stays cool.

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