Integrated Geothermal - California Style

Green Executives story - cnasir9

The Chief Executive developing one of the planet's richest geothermal and critical mineral fields.

Rod Colwell is the Chief Executive of Controlled Thermal Resources (CTR). He has spent close to two decades at the Salton Sea in California's Imperial County, assembling what is on track to become one of the largest integrated geothermal and critical-minerals operations on Earth.  

Power is targeted for the first quarter of 2028, with minerals shortly after.

Yet ask him what drew him to this stretch of desert and the answer is almost defiantly unromantic.

"We don't like risk, to be honest," he says. "We don't like wildcatting and throwing money into wells that may or may not work." 

That instinct explains everything that follows.

When CTR was choosing a site in the late 2000s, the Salton Sea offered the one thing geothermal rarely does, certainty. The first wells went down in the 1950s; the very first, Colwell notes, at a spot called Hell's Kitchen, a dance hall and bar between 1908 and 1915. Commercial operations have run continuously since 1980.

"Before you even had to employ a geologist," he says, "you could sit down with an operator that has been operating these plants for decades, and they'd give you the lowdown on how proven the resource was."

The figures bear out the confidence: 650 megawatts independently validated by Baker Hughes, with potential beyond a gigawatt. He adds, "That's not theorised. That's proven."

What is unusual is the shape of the plan.

CTR's master plan calls for 40 wells across a 4,000-acre footprint — production, injection, headers — a layout that looks less like a typical geothermal project and more like an oilfield in Odessa. That is deliberate.

The company keeps an office in Houston specifically to draw on the oil and gas skill set, and its Baker Hughes partnership is the same logic at scale.

"Big oil only does it best," Colwell says.

Could a geothermal company really run like an oil major? In his telling, at this size, it is the only sensible way to build.

Then comes the positioning that sets CTR apart.

Colwell does not want to be measured as a lithium producer. 

"We'd rather be known as a critical minerals company, not a lithium company. Single play lithium is a difficult business." 

Brine, historically a corrosion problem, below the Salton Sea carries 23% total dissolved solids, is now a key part of the company's portfolio. CTR counts 34 federally listed critical minerals in its brine and has proven economic recovery of four. Manganese, zinc and potash sit in the same stream as the lithium, and recovery has the luxury of being optional: the power plants must run continuously, but the minerals circuit can be turned on and off with the market, off-spec brine simply re-injected.

That flexibility is his answer to the price volatility that has rattled lithium since 2022 — a narrative he rejects flatly. 

"Lithium was never $80,000, and it was never $8,000 in the real world," he says, blaming thin trades by Chinese-owned buyers. His own steady-state view is narrower: $22,000 to $27,000 a tonne.

None of this is cutting-edge, and that is the point.

CTR did not invent its technology — direct lithium extraction has existed since Dow Chemical ran it in 1961 — and the corrosive Salton Sea brine is handled with proven engineering, not new tricks. The Vonder well, in titanium alloy since 1991, still produces 58 megawatts. Across more than 300 wells in the field, there have been only two mechanical failures. 

"It might be a little more boring," Colwell says, "but it's reliable at high capacity. These are typically very high-leverage debt plants because the market's so comfortable with the reliability."

Reliability, it turns out, is exactly what infrastructure capital pays for — and what venture-style returns rarely deliver.

The region itself has its own challenges.

Unemployment can reach 17 to 18 per cent and rainfall is under three inches a year. Colwell points to eight years of community work, more than 200 stakeholder meetings, a commitment that 95 per cent of jobs will be filled locally and Imperial Valley College already training operators. A state extraction tax routes the bulk of royalty revenue back to the county. 

CTR's route to the public markets

Public markets runs through its March 2026 merger with Plum Acquisition Corp IV — a path Colwell tried once before, in 2021, and abandoned when the market wasn't ready. This time, he argues, demand for both US baseload power and domestically produced minerals has converged.

Future vision

Ask him what CTR looks like in 2035 and the ambition is plain: one of the largest critical-minerals and power facilities on the planet.

 "If I'm still kicking around," he adds, "I'd love to have that conversation."

The contest is not America's alone.

In Germany's Upper Rhine Valley, Vulcan Energy is building Europe's benchmark integrated project at industrial scale, and China — which the IEA counts among the three countries holding most of the world's next-generation geothermal potential — is moving fast on policy and ambition.

CTR's answer is scale on proven ground: one of the largest validated geothermal resources anywhere, paired with the kind of domestic critical-minerals stream the West is now racing to secure.

In a sector that has long asked investors to gamble on what lies beneath, Rod Colwell has built a company designed not to.

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