While it’s true that some estimates exist about subsurface heat source availability,  drilling remains the only way to figure out what's truly available. And the high cost of operating an exploration rig leaves little room for misses.

Most of the ultra-high-temperature, shallow reserves were discovered and developed in the 1960s and 70s. As a result, the geothermal industry had to drill deeper -- 10,000 ft. vs. 3,000 ft. -- to find heat sources suitable for power generation.

Drilling deeper wells became cost-prohibitive. About one out of three projects aren't commercially viable, from a resource perspective, Latimer said. A well can cost $5 million to drill, and every additional foot deeper is exponentially more expensive.

"You really can't scale that as a resource in very competitive power markets. And so, if you want to scale geothermal, the problem that you have to address is you can't afford to drill a bunch of wells that don't actually produce anything," Latimer said.

Fervo Energy's production and injection wells aren't next to each other vertically— they're stacked on top of each other horizontally. In practice, that means the company drills 10,000 ft. down and then 5,000 ft. horizontally, with the wells in horizontal strata a few hundred feet apart.

With that approach, Fervo Energy isn't trying to find a heat resource using a seven-inch pipe in the subsurface. Instead, they have more than a mile to assess as the subsurface, overcoming a lot of the hit-or-miss drawbacks of geothermal.

These innovations are not new and have been tested and proven by the oil and gas industry, allowing Fervo Energy to move quickly to market.

Like millions of Texans, Latimer lost power when Winter Storm Uri hit the state with extreme cold weather in Feb. 2021. He sees geothermal as both an answer for deep decarbonization and reliability challenges.

Resource availability has become a focus of Texas grid regulators and lawmakers ever since the storm. Renewables like wind or solar have faced heightened criticism for their variability.

Deep decarbonization will require a portion of capacity to come from clean, firm power sources that can be dispatched any time. Wind, solar, and batteries can do most--but not all--of the job.

Fervo Energy's mission is to scale geothermal power production to the point where it can be that missing piece. Twelve states have already passed laws mandating 100% clean energy and are looking for that answer now. 

"Even with low-cost batteries, every study kind of comes up with the same result that getting more than perhaps 60-80% of your grid from clean electricity in a year requires you to get solutions that go beyond wind and solar batteries if you want it to be cost-effective," Latimer said.

Fervo Energy is working with Princeton's ZERO Lab, Lawrence Berkeley National Lab and Rice University on a research project that is looking at geothermal power production’s ramping capability to meet the real-time needs of the grid.

In the West, where daytime power prices are often negative due to the availability of solar power, around-the-clock geothermal power generation doesn't make sense. Instead, researchers are examining how to feasibly trap pressure in geothermal reservoirs as a form of energy storage to be used when the sun sets.

"The project doesn't reply on anything that hasn't been proven out or technically shown in the field," Latimer said. "The question is how do you take those parameters and create a system that's optimized."

Latimer and Fervo Energy believe that geothermal energy will follow a learning curve that becomes cheaper and cheaper after thousands of wells have been drilled.

But starting out has been difficult. Early on, customers told Latimer that they would love to get involved after a few of the (very expensive) initial projects had been brought online. The market for geothermal didn't really exist.

That all changed with Google's 24/7 carbon-free electricity movement. Several years ago, the company said it had met and exceeded its 100% renewable energy procurement target. Looking to go a step further, it made a pledge to match every hour of energy consumption with clean energy.

Google's backing paved the way for Fervo Energy's first project, a 5 MW facility near Las Vegas, Nevada, that's expected to come online early in 2023.

Another major step to establishing a market for geothermal power generation has been California's 2021 requirement for load serving entities to procure 1,000 MW of non-weather-dependent, zero-emissions energy.

As a result, Fervo Energy secured a 15-year power purchase agreement from a group of nine California-based community choice aggregators for a 20 MW geothermal project under development in Beaver County, Utah.

The project is expected to begin operation in the first half of 2026.

Latimer wants to go beyond megawatt-hour accounting, though. He wants geothermal to directly power operations with clean electricity.

"That's why we did the deal with Google," he said. "We need some sort of catalytic customer to come through and say, 'Yeah, we understand the value of this long-term.'"

Listening to Latimer speak, he's as obsessed with geothermal energy today as he was when he first learned about the technology in the oil fields of Texas a decade ago.

The systems are proven. And there's no question that geothermal could serve as a crucial piece of a decarbonized grid. Now, one of the only breakthroughs left is public awareness.

"We need to make sure we're raising awareness about geothermal so that people actually understand this is every bit as important as solar," Latimer said. "And, in fact, even more so because this is going to be that critical piece that allows us to keep the lights on 24/7."

Fervo Energy is a member of the Texas Geothermal Energy Alliance, which formed in 2022 to advance and advocate for the industry. Barry Smitherman, the president and chairman of the TxGEA, appeared on a recent episode of the Texas Power Podcast.

Much of the alliance’s work is focused on geothermal energy receiving the same attention, and policy support, of other renewable energy sources, like wind and solar.

The federal Investment Tax Credit and Production Tax Credit programs that have fueled solar and wind project development in the U.S. have not historically applied to geothermal. This "discrete policy decision," as Latimer puts it, has been one of geothermal’s biggest challenges to overcome.

On the permitting front, the Energy Act of 2005 helped streamline oil and gas drilling. That policy does not extend to geothermal drilling, even though the processes are very similar.

"Being forgotten hurts geothermal in many policy ways," Latimer said. "We have to develop projects oftentimes that don't have the economic support that other renewables get, but then also don't have the permit streamlined support that fossil fuel projects get."

The Inflation Reduction Act has brought significant relief to the geothermal industry. The climate law extends tax credits to all zero-carbon-emitting power-generating technologies starting in 2023.

The law gives Latimer and Fervo Energy certainty for, at least, the next 10 years. When geothermal was included in prior tax credits, it was never longer than 12 months.

"It's really difficult to plan a business around that," Latimer said. "The IRA brings an enormous amount of certainty into the business for us."