Clean Energy Alliance Signs Exclusive Letters of Intent with GreenFire Energy, Ignis H2 Energy, and TLS Geothermics to Advance Geothermal Commitment

Always-On Earth: How a California Energy Alliance Is Betting Big on Geothermal to Reach 100% Renewables by 2035

By Robert Buluma 

June 12, 2026

For years, the clean energy debate has been dominated by two icons of the new economy: the solar farm and the wind turbine. They are visible, rapidly deployable, and have driven down the cost of renewable electricity to historic lows. But they carry an inherent weakness – intermittency. The sun sets. The wind lulls. And when that happens, the grid must scramble for backup, often turning to natural gas.

On June 11, 2026, the Clean Energy Alliance (CEA), a community choice aggregator serving North San Diego County, announced a decisive move to solve that problem. By signing four exclusive letters of intent (LOIs) with three geothermal developers – GreenFire Energy Inc., Ignis H2 Energy Inc., and TLS Geothermics – CEA is placing a multi-megawatt bet on the heat beneath our feet. The goal: to build an “always-on” backbone of clean, firm power that can finally make the elusive promise of 100% renewable energy a practical reality.

This article unpacks the significance of those agreements, explores the technologies behind each developer, and examines why geothermal – long the forgotten renewable – is suddenly central to California’s decarbonization strategy.

Part One: The Firm Power Imperative

California has set some of the most ambitious clean energy targets in the world. By 2035, the state aims to generate 90% of its electricity from carbon-free sources, and the Clean Energy Alliance has aligned itself with an even more aggressive internal goal: 100% renewable energy for its customers by the same year.

But as CEA’s CEO Greg Wade noted in the official announcement, “the need for additional clean, firm renewable resources has never been greater.” The keyword is firm – a term utility planners use to describe power that is dispatchable on demand, regardless of weather or time of day.

Today, the only carbon-free firm resources available at scale are hydropower (constrained by drought and environmental limits), nuclear (politically contentious and expensive to build), and geothermal. Geothermal power plants tap into the Earth’s natural underground heat, which remains constant 24/7, 365 days a year. A well-designed geothermal field can deliver capacity factors of 90% or higher – rivaling nuclear and far exceeding solar (which typically achieves 20-25% in California) and onshore wind (30-35%).

For CEA, which serves communities including Carlsbad, Del Mar, Solana Beach, and Encinitas, the economics of intermittency have become impossible to ignore. The more solar and wind they add to their portfolio, the more they need to purchase expensive battery storage or pay natural gas plants to stand idle, ready to ramp up at a moment’s notice. Geothermal collapses that complexity into a single, elegant solution: a power plant that simply runs.

The letters of intent signed this week are not yet final power purchase agreements, but they are far stronger than a memorandum of understanding. Under the terms of these “exclusive” LOIs, CEA and the developers agree to negotiate in good faith, with CEA providing crucial early-stage backing that developers can use to secure financing. In return, CEA locks in priority access to what will likely be some of the most valuable megawatts on the grid by the early 2030s.

Part Two: GreenFire Energy – Scaling a Next-Generation Portfolio

Of the three developers, GreenFire Energy Inc. has the most immediately tangible offering for CEA. Headquartered in Oklahoma City, GreenFire is not a wildcat explorer; it is a next-generation geothermal developer advancing scalable, carbon-free baseload power projects across the United States.

Under the terms of its Geothermal Portfolio Advancement & Commercial Term Sheet (GEOPACT) Letter of Intent, GreenFire is advancing a portfolio of three distinct sites across California. Together, those sites are expected to deliver up to 100 megawatts (MW) of reliable, carbon-free baseload power specifically for CEA.

To put that in perspective: 100 MW can power roughly 75,000 to 100,000 homes, assuming 24/7 availability. That is a substantial chunk of CEA’s projected load growth over the next decade.

GreenFire’s technology approach is pragmatic rather than revolutionary. They specialize in closed-loop and enhanced geothermal systems (EGS) that can be deployed in areas without naturally occurring hydrothermal reservoirs – places where traditional geothermal drillers would walk away. By circulating a working fluid through a sealed loop of deep wells, they extract heat from hot, dry rock and bring it to the surface to drive a turbine. The result is geothermal power that can be built almost anywhere there is heat at depth, not just in geologically privileged spots like The Geysers in Northern California.

Cory Draper, GreenFire’s Chief Operating Officer, framed the partnership as a strategic alignment of long-term visions: “California represents a significant long-term opportunity for next-generation geothermal development, and these projects are an important step in expanding GreenFire Energy’s growing portfolio of geothermal offtake opportunities across the state. We’re excited to work with Clean Energy Alliance to help deliver reliable, around-the-clock carbon-free power that supports long-term grid reliability and energy resilience.”

For CEA, the GreenFire portfolio offers diversification within geothermal itself. By contracting across three sites, they reduce the risk of a single reservoir underperforming. And by locking in 100 MW from a developer with a proven commercial model, they send a powerful signal to other investors that California’s CCAs are serious about firm renewable power.

Part Three: Ignis H2 Energy – The Oil & Gas Approach to De-Risking

Where GreenFire offers portfolio scale, Ignis H2 Energy Inc. offers something arguably more valuable for early-stage development: subsurface certainty. Based in Houston, Ignis brings the discipline of the oil and gas industry – exploration analytics, drilling rigor, and reservoir engineering – to the geothermal frontier.

Ignis is building a multi-basin, multi-country portfolio of “high-enthalpy” projects (geothermal systems with very high temperatures, ideal for efficient electricity generation) across the Western U.S., Türkiye, Italy, and Indonesia. But their signature contribution to the CEA partnership is the Weepah Hills project in Esmeralda County, Nevada.

Weepah Hills is not a greenfield guess. Ignis has conducted modern geophysical surveys, including magnetotelluric (MT) acquisition and 2-meter temperature surveys, to systematically confirm reservoir presence. They have picked well positions. And most importantly, drilling is expected to commence within 60 days of the LOI signing – an astonishingly rapid timeline by geothermal standards.

This is not an accident. Ignis’s philosophy, articulated by CEO Richard Calleri, is deliberately unsentimental: “Geothermal becomes infrastructure when decisions are driven by converging subsurface evidence, not optimism.” In other words, they treat a geothermal prospect like an oil field: you prove the resource, then you build the plant.

The company’s Hybrid Geothermal Solution (HGS) is technology-agnostic. Rather than committing upfront to a single method (hydrothermal, enhanced geothermal, or advanced geothermal), Ignis drills exploration wells, measures the reservoir’s temperature, permeability, and pressure, then selects the optimal development pathway. It is a Bayesian approach to clean energy – constantly updating the probability of success as new data arrives.

COO Marcus Oesterberg added a characteristically blunt statement: “Geothermal doesn’t scale on optimism. It scales on proven heat, disciplined exploration, and partners willing to engage early. CEA is doing exactly that.”

For CEA, the Ignis partnership is a vote of confidence in the exploration-first model. If Weepah Hills confirms a high-enthalpy resource, it could become a flagship for how utility-scale geothermal is developed across the Great Basin region, which some geologists believe holds enough accessible heat to power the entire Western U.S. for centuries.

Part Four: TLS Geothermics – Machine Learning Meets Deep Earth

The third developer, TLS Geothermics, represents the most technologically avant-garde member of the trio. Headquartered in Europe with a growing transatlantic portfolio, TLS is redefining geothermal exploration using advanced computational science, machine learning, and systems-based geoscience.

Traditional geothermal exploration is expensive and failure-prone. Drill a dry hole, and you have lost millions of dollars and years of time. TLS’s innovation is to dramatically reduce that exploration uncertainty before a single rig arrives. Their proprietary algorithms ingest massive datasets – seismic surveys, satellite imagery, geological maps, even historical drilling logs from abandoned oil wells – to identify high-potential geothermal systems concealed within complex subsurface fault networks.

Where a human geologist might see a jumble of rock layers, TLS’s machine learning models detect subtle thermal and structural patterns that predict the presence of superhot water or dry rock at viable drilling depths. The output is a probabilistic resource assessment that tells a developer: “Here is the 85% confidence interval for temperature at 3,000 meters.”

Mathieu Auxietre, CEO of TLS Geothermics, connected the technology directly to CEA’s mission: “As California accelerates toward its ambitious clean energy goals, the need for reliable, 24/7 clean power has never been more urgent. We are thrilled to partner with Clean Energy Alliance to help meet that need. By combining CEA’s forward-thinking vision with TLS’s geothermal expertise, we can help unlock the Earth’s heat as a source of clean, firm power for California’s evolving grid.”

TLS does not just generate electricity; their systems can also provide direct heating and cooling, offering a potential second revenue stream for district heating projects. While the initial LOI with CEA focuses on power generation, the partnership leaves the door open for combined heat and power (CHP) applications in North San Diego County’s industrial and commercial districts.

For a CCA like CEA, which is also exploring energy efficiency and demand response programs, TLS’s dual-use capability is intriguing. A geothermal plant that delivers both firm electricity and waste heat for a greenhouse complex or a hospital campus is a more efficient use of the resource than a pure power plant – and efficiency is, after all, the cheapest form of clean energy.

Part Five: Why Early-Stage Backing Matters

One of the most important – and least understood – aspects of the CEA announcement is the nature of the financial commitment. The letters of intent are “exclusive” and include pre-construction investment support. This is not a simple offtake agreement for power that has already been built. It is a bet on the development process itself.

Geothermal projects face a “valley of death” between exploration and construction. A developer may have a promising geological survey, but without a utility or CCA willing to sign a contingent agreement, banks will not lend drilling capital. The result is a chicken-and-egg problem: no power purchase agreement, no drilling; no drilling, no proven resource; no proven resource, no power purchase agreement.

By signing these LOIs, CEA breaks that cycle. They provide developers with a credible document they can take to project finance lenders, saying, “A real utility with 1,300+ commercial and residential customers has committed to negotiate a long-term contract for the output of this project.” That signal alone can unlock bridge loans, equipment financing, and even state-level clean energy grants.

CEA’s board clearly understands that waiting for geothermal projects to become “shovel-ready” before offering support is a recipe for never getting any. The projects that will be online in 2030 are the ones being de-risked today. And by entering exclusive agreements now, CEA ensures that when those megawatts finally flow, they will flow to North San Diego County, not to some other utility that was slower to act.

Greg Wade, CEA’s CEO, emphasized this forward-leaning posture in the announcement: “CEA recognizes the importance of early-stage support for geothermal projects in facilitating the investment needed to bring these projects through their preconstruction development process.”

That sentence is quietly revolutionary. Most utilities view preconstruction risk as something developers should bear. CEA is explicitly saying: we will share that risk in exchange for priority access to a scarce resource – firm, clean, 24/7 power. It is a model that other CCAs and investor-owned utilities may soon be forced to copy as competition for renewable firm power intensifies.

Part Six: The Diversification Strategy

Beyond the technical and financial details, the CEA announcement reveals a sophisticated approach to portfolio diversification. The three developers could hardly be more different:

· GreenFire Energy offers a portfolio of three sites, spreading risk across multiple locations and using closed-loop technology that works in medium-temperature rock.

· Ignis H2 Energy offers a single, high-reward exploration project (Weepah Hills) with oil-and-gas-caliber discipline and a very short timeline to resource confirmation.

· TLS Geothermics offers a machine-learning-driven exploration pipeline that could identify entirely new geothermal resources in areas previously written off as geologically dead.

If any one of these bets fails – if GreenFire’s first site underperforms, or Ignis’s Weepah Hills well comes up dry, or TLS’s algorithms send them to a barren fault – the other two are still in play. And if all three succeed, CEA will have a surplus of firm renewable power that it can sell to neighboring CCAs or the California Independent System Operator (CAISO) wholesale market, generating revenue to lower customer bills.

This is precisely the kind of portfolio thinking that has long been applied to solar and wind development (buying power from multiple farms across different wind regimes) but has been rare in geothermal, where most utilities have treated it as a one-off “nice to have.” CEA is treating geothermal as a core resource class, with a diversified set of developers, technologies, and geological basins.

Part Seven: Challenges Ahead – Permitting, Transmission, and Cost

No serious article about geothermal development in the Western U.S. can ignore the obstacles. Permitting remains a nightmare. A geothermal project on federal land (much of the Great Basin is managed by the Bureau of Land Management) can take five to seven years to navigate environmental reviews, cultural resource surveys, and National Environmental Policy Act (NEPA) compliance.

California adds its own layer of complexity through the California Environmental Quality Act (CEQA), which, while well-intentioned, has been used by opponents to delay renewable energy projects for decades. And even after a project is permitted and drilled, it needs transmission access – a high-voltage line to carry power from rural Nevada or Eastern California to coastal load centers like North San Diego County. Those lines are congested, expensive to build, and often face their own local opposition.

CEA cannot solve these problems alone. But by signing these LOIs, they add their political voice to the growing chorus of utilities demanding permitting reform. When a CCA representing hundreds of thousands of customers tells the BLM or the California Energy Commission, “We need this project to meet our 100% renewable mandate,” it carries weight.

Cost is another unknown. Geothermal power has historically been more expensive than utility-scale solar, with levelized costs ranging from $60 to $100 per megawatt-hour (compared to $30-$40 for solar). However, those figures do not account for the cost of firming – the batteries or gas plants needed to back up solar. When you compare the system cost of a high-renewables grid, geothermal starts to look very competitive, especially as battery prices plateau after years of decline.

CEA’s ratepayers will ultimately bear the cost of these projects. The Alliance has not yet released projected rates from the LOIs, but the fact that they are pursuing exclusive agreements suggests they have seen internal modeling that makes the math work, especially when paired with federal tax credits (the Inflation Reduction Act’s investment tax credit applies to geothermal at 30%, with bonuses for domestic content and energy communities).

Part Eight: A Template for the 2035 Grid

Perhaps the most important takeaway from the CEA announcement is its replicability. There is nothing unique about North San Diego County that makes it especially suited to geothermal power. The heat is not under their feet; it is under Nevada and the Salton Sea. What CEA has done is demonstrate that a community choice aggregator – a relatively small, customer-focused utility – can act as a first mover in an emerging asset class.

Other CCAs across California, including Marin Clean Energy, Peninsula Clean Energy, and East Bay Community Energy, are watching closely. So are investor-owned utilities like PG&E, SCE, and SDG&E, which have their own ambitious decarbonization targets but move more slowly due to regulatory constraints.

If the CEA model works – if GreenFire, Ignis, and TLS successfully convert these LOIs into operating power plants by the early 2030s – it will create a blueprint. That blueprint will read something like this:

1. Identify the need for firm, clean power years before it becomes a crisis.

2. Sign exclusive early-stage agreements with a diversified set of developers.

3. Provide pre-construction support to bridge the valley of death.

4. Advocate for permitting reform and transmission access as a coalition.

5. Convert successful projects into long-term power purchase agreements that stabilize rates for a decade or more.

CEA has completed step one and two. Steps three through five will play out over the next four to six years, with the first resource confirmation wells from Ignis scheduled within 60 days.

Conclusion: The Quiet Revolution

Geothermal has never been glamorous. It lacks the sleek panels of a solar farm or the majestic blades of a wind turbine. A geothermal plant is a collection of pipes, turbines, and cooling towers, often located in remote desert valleys, making a low, constant hum. But that hum is the sound of reliability – of a machine that does not care whether the sun is shining or the wind is blowing.

With their June 11 announcement, the Clean Energy Alliance has bet that this humble, ancient energy source will be the backbone of California’s 100% renewable future. They have signed with a portfolio-scale developer (GreenFire), an exploration-first oil-and-gas shop (Ignis), and a machine-learning pioneer (TLS). Three very different gambles, all on the same proposition: that the Earth’s heat is the firm, clean, always-on resource we have been looking for.

The next few years will tell whether that bet pays off. But one thing is already clear: while much of the energy world is still debating whether batteries are enough, CEA has moved on. They are drilling.

See also: Endurance Energy raises $54M to harness a massive untapped energy source on the ocean floor

Source: Clean Energy Alliance 

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