Geothermal energy, or tapping Earth’s internal heat for power, has long been prized for one attribute: it runs 24 hours a day as “baseload” power. When the sun doesn’t shine and the wind doesn’t blow, the Earth’s core is still hot. This promise of consistency could make geothermal a darling of the green energy revolution, but until now its global footprint has stayed tiny. That’s because conventional projects require rare, naturally porous “sweet spots” near volcanic zones. Even today, the world’s installed geothermal capacity is just ~16.9 GW, supplying well under 1% of global electricity. Yet the calculus is shifting, and that small starting base sets the stage for outsized growth. In this report, we highlight the top geothermal energy stocks to watch in 2025—curated for their exposure to surging demand from AI/data centers and breakthroughs in next-generation geothermal tech.
Why Geothermal, Why Now?
First, electricity demand is surging, in large part driven by AI data centers. The International Energy Agency projects data-center consumption will roughly double to 945 TWh by 2030—almost Japan’s entire power use today—driven largely by AI workloads. In the United States alone, Morgan Stanley warns hyperscale clouds may need an extra 65 GW of firm capacity before the decade is out, far exceeding what the grid can readily supply. Utilities and corporations therefore need carbon-free power that behaves like a thermal plant, and geothermal is one of the few technologies that fits that brief.
Second, just as this pull emerges, supply-side technology is breaking old constraints. Advances in drilling technology—ironically borrowed from the fossil fuel industry—promise to extend geothermal’s reach far beyond volcanic belts. The U.S. Department of Energy’s 2024 Pathways to Commercial Liftoff analysis finds that enhanced, closed-loop, and “super-hot” drilling methods could unlock around 5,500 GW of technically recoverable geothermal in the United States alone—roughly four times the nation’s entire installed capacity of all sources today. The DOE’s “Enhanced Geothermal Shot” aims to slash costs 90% to $45/MWh by 2035, a price that would undercut many gas-fired plants. If these technologies scale, geothermal could meet up to 15% of global electricity-demand growth through 2050.
In short, an unprecedented pull from power-hungry industries is meeting a wave of cutting-edge breakthroughs that make a broader range of geothermal projects economically feasible.
How to Invest in Geothermal Energy
The challenge to investing in geothermal energy stocks is that they’re not easy to find. While solar and wind have options for pure-play stocks, geothermal is still in the early innings of creating its own market niche. Geothermal operators tend to be either private startups or diversified energy players—big firms with geothermal divisions that might be a footnote on their balance sheets.
For example, Ormat is one of the few pure-play geothermal stocks on the market. But beyond that, other operators are either subsidiaries of larger firms or only have geothermal as a small portion of their mix. Therefore, in this report, we’ll also consider alternative angles to invest in geothermal, such as well development, services, and strategic backers. Finally, we’ll also highlight the top private companies to watch, especially in the event of an IPO or acquisition.
Geothermal Energy Operators
These companies own the power plants and the underground resource, making them the obvious angle for geothermal energy stocks. Because very few such assets are publicly traded, the group is thin—but those that exist offer exposure to long-term power-purchase contracts and, increasingly, to high-margin by-products like battery-grade lithium.
Ormat Technologies (NYSE: ORA)
HQ: USA; Pure-play geothermal operator with leadership in binary systems.
Ormat is currently the only pure-play geothermal energy stock. As the largest manufacturer of organic-Rankine-cycle (ORC) binary equipment, it’s also the second-largest owner/operator of geothermal fields globally. Its projects provide reliable 24/7 renewable baseload power, precisely what hyperscale AI data centers crave. For example, in 2024 Ormat signed contracts totaling 77 MW and was negotiating another 250 MW of power sales to utilities and tech firms at rates above $100/MWh. This pricing power reflects Ormat’s unique position: it can guarantee uninterrupted carbon-free energy when intermittent sources can’t, an advantage that only grows as data centers expand.
At the same time Ormat is expanding by acquisition (e.g., buying Enel’s geothermal assets) and technology (e.g., integrating battery storage). The company has taken a patent license in enhanced geothermal (EGS) and even partnered with its former rival SLB to combine Ormat’s field expertise with cutting-edge drilling and subsurface tech. Internally, Ormat is aggressively exploring new fields, adding promising land in Nevada and Utah and accelerating deep-core drilling projects. By retrofitting traditional oil and gas ideas for geothermal, Ormat aims to unlock reservoirs that were previously too cool or deep. This focus on cutting‑edge projects, combined with Ormat’s deep experience and tech leadership in binary systems, means the company can scale into new markets like AI data centers faster than peers.
Constellation Energy (NASDAQ: CEG)
HQ: USA; Combines nuclear and the largest U.S. geothermal fleet.
Constellation has fast-tracked its presence in geothermal by acquiring Calpine’s massive portfolio. In January 2025 Constellation announced it would buy Calpine in a deal that makes it the country’s largest clean energy company. The move combines Constellation’s nuclear fleet with Calpine’s natural gas and geothermal assets, including The Geysers in California – the largest U.S. geothermal site. The company will now have coast‑to‑coast scale (especially in Texas and California, key data center hubs) with roughly 60 GW of low‑ or zero‑carbon capacity. In fact, Constellation has already signaled a pivot to serving AI data centers by supplying grid-connected power, underlining that their expanded baseload portfolio (nuclear+geothermal) is a perfect match for 24/7 computing needs.
Constellation is also investing in next-gen geothermal tech. Its venture arm led a funding round for XGS Energy, a startup developing closed-loop geothermal wells that use ultra‑conductive materials to unlock heat anywhere. The company’s scale and capital – combined with these tech investments – create a unique position to push geothermal into new geographies and applications. In short, while not a pure-play geothermal energy stock, Constellation is a bet on the largest firm power fleet, with boosted upside from cutting‑edge geothermal R&D.
Berkshire Hathaway Energy (NYSE: BRK.B)
HQ: USA; Geothermal power plus lithium extraction from Salton Sea brines.
While far from being a pure-play geothermal energy stock, Berkshire Hathaway Energy – largely through its CalEnergy subsidiary – owns one of the world’s largest geothermal portfolios in California’s Salton Sea region. The company operates ten geothermal plants that process an enormous 50,000 gallons of brine per minute to generate about 403 MW of baseload power. This dual wealth of heat and minerals gives BHE a strategic edge: while others chase power sales, BHE can monetize lithium and other battery metals from the same wells.
In fact, those minerals beneath its plants might be BHE’s most compelling growth opportunity. The company is betting on extracting lithium from its geothermal brines – a “white gold” that could turn its power stations into battery-metal mines. BHE’s Imperial Valley plants could yield an estimated 90,000 tonnes of lithium carbonate per year (about 15% of global lithium demand) if fully tapped. To pursue this, BHE formed a joint venture with Occidental’s TerraLithium to demo direct lithium extraction technology at its geothermal fields. In this way, BHE is leveraging its geothermal expertise and brine flow to become a leader in “Lithium Valley.”
Geothermal Well Development & Services
Here we find the oil-field service giants—and a handful of nimble specialists—pivoting their rigs, high-temperature pumps and subsurface software toward geothermal. For investors, these geothermal energy stocks offer indirect upside with insulation from single-project risk.
SLB (NYSE: SLB)
HQ: USA; Oil-field service giant offering full-stack drilling for geothermal.
SLB (Schlumberger) is the world’s largest oilfield services firm, but it also boasts involvement in about 80% of the world’s geothermal projects. It’s now further adapting its subsurface expertise into geothermal, offering everything from seismic exploration to completion technology. For example, SLB recently partnered with Indonesia’s Star Energy Geothermal to co-develop new AI-driven tools for geothermal wells. This collaboration aims to “shift the economics” of projects by improving recovery rates and mapping underground heat reservoirs more accurately. SLB’s involvement spans from 3D seismic and logging to specialized drill bits and casing technology.
SLB’s competitive edge is that it already has the global footprint, data, and equipment to tackle hard geothermal projects. As demand for reliable baseload power rises, SLB is positioned to capture a share of every new geothermal project by supplying both technology and field services. In essence, SLB has a head start in what could become a huge new market if EGS and other innovations take off. It would leverage its existing drilling and reservoir expertise to dominate geothermal field services as the industry grows, much as it already does for oil and gas.
Halliburton (NYSE: HAL)
HQ: USA; High-temp pumps and tools for deeper, hotter geothermal wells.
Halliburton is adapting from an oilfield service to a geothermal technology supplier, focusing on the hardware challenges of heat and corrosion. Its core differentiator is novel downhole equipment built for geothermal extremes. For instance, in 2024 Halliburton unveiled “GeoESP” submersible pumps that operate at up to 220 °C and resist solids, scale, and corrosion. These pumps use high‑flow inlets and hardened materials so that “efficient, safe…solutions” can lift super‑heated brine reliably. This is a big deal: conventional oilfield pumps burn out at high temperature, forcing geothermal wells to run at sub‑optimal output. By contrast, Halliburton’s GeoESP lets plants tap more of the heat at high flow, boosting power output per well.
Halliburton’s innovation push extends beyond pumps to digital well management. It now markets an “Intelevate” digital platform to monitor and optimize geothermal wells. By combining rugged hardware with data analytics, Halliburton offers customers a turnkey solution to the toughest geothermal problems, such as in handling steam and corrosive fluids. As geothermal demand rises, customers will increasingly choose service partners who can guarantee uptime. Halliburton’s high‑temperature equipment and monitoring tools fit that bill, giving it a foothold in projects others can’t easily service.
Baker Hughes (NASDAQ: BKR)
HQ: USA; Integrated geothermal developer with DoD-vetted capability.
Baker Hughes brings its oil‑and‑gas pedigree to geothermal with a vision of end‑to‑end project delivery. The company emphasizes that it has been a “pioneer in this field for more than 40 years” with subsurface‑to‑surface expertise. Its strategic advantage is leveraging that experience across the entire geothermal value chain. For example, in March 2025 Baker Hughes earned “awardable” status from the U.S. Department of Defense, meaning it can now propose utility‑scale geothermal plants to power military bases. Beyond government work, Baker Hughes has also backed geothermal startups. In 2022, it took a stake in GreenFire Energy, a company developing closed-loop geothermal systems. Together they intend to retrofit inactive oil/gas wells into renewable heat wells.
Baker’s broad portfolio — drilling and completion services, separation equipment, subsea technology, even carbon capture — gives it multiple touchpoints with geothermal developers and utilities. This diversity is a strategic moat: Baker can bundle financing and know‑how to deliver an entire project, not just sell a pump. In a market for 24/7 clean power, customers flock to vendors that can underwrite risk. Baker’s half‑century track record and recent DoD endorsement position it as that partner for large, capital‑intensive geothermal installations.
Helmerich & Payne (NYSE: HP)
HQ: USA; FlexRig drives fast, horizontal drilling for enhanced geothermal.
Helmerich & Payne, the drilling‑rig specialist, is carving out an unusual niche in geothermal by applying its high‑tech rig fleet and venture capital muscle to emerging EGS projects. H&P’s FlexRig machines, known for automation and agility, can drill high‑angle and horizontal wells faster than competitors. The company has publicly declared support for “unconventional geothermal” and continues to invest in startups. A case in point is H&P’s investment in Fervo Energy, a U.S. startup that uses horizontal drilling and fiber‑optic monitoring to unlock hot, hard rock. This aligns perfectly with H&P’s DNA: Fervo’s approach essentially brings petroleum drilling methods to geothermal, and H&P’s rigs are built for exactly that kind of drilling.
High‑quality drilling is a barrier to geothermal expansion, and H&P can remove it. Its FlexRig fleet has the industry’s best reputation for uptime, automated controls and deep drilling capability. Moreover, H&P ties outcomes to performance (through outcome‑based contracts), aligning incentives with customers. In today’s market, any geothermal project struggling to hit target flow and temperature can simply contract H&P to get there reliably. That gives H&P a sales pitch and moat: “we drill the wells that others can’t.” Combine that with its strategic tech investments like Fervo and it means H&P is helping pioneer the next‑gen geothermal model.
Liberty Energy Inc. (NYSE: LBRT)
HQ: USA; Modular completions and microgrids for data centers.
Liberty Energy is a smaller but nimble energy services company that has quietly staked out a hybrid niche in geothermal and distributed power. On the geothermal side, Liberty provides completion and pumping services (fracking, cementing, well pumping) to oil, gas and “enhanced geothermal” projects across North America. It’s not the biggest player, but it aims to use technology to differentiate – for instance by acquiring specialized equipment firms and developing modular completion kits. The company also participated in a large funding round for Fervo Energy in 2022.
Where Liberty really stands out is its pivot into electricity solutions for data centers. In March 2025 Liberty acquired IMG Energy Solutions, a developer of modular microgrid power systems. IMG’s “modular power block” designs, essentially self‑contained microgrids, can be rapidly deployed to meet resiliency needs for data centers. This move allows Liberty Energy to be a one‑stop shop for powering mission‑critical facilities with clean baseload energy plus storage or backup. In the near term, this may mean selling geothermal‑plus‑battery packages or hybrid generation solutions directly to corporate customers. Over time, if distributed energy and on‑site AI loads take off, Liberty could grow into a valuable niche utility.
Geothermal Technology & Strategic Ventures
Turbine makers, heavy-equipment suppliers, and strategic backers form this segment of geothermal energy stocks. Their core business is selling (or retrofitting) the turbines, heat exchangers and control systems that keep plants running. At the same time, many take minority stakes or JVs in breakthrough projects, giving shareholders a picks-and-shovels angle on geothermal expansion.
Mitsubishi Heavy Industries (OTCMKTS: MHVIY)
HQ: Japan; Turbine titan funding and equipping next-gen geothermal plants.
Mitsubishi Heavy Industries is best known as a global turbine and power systems manufacturer, but it’s quietly stepping into geothermal through strategic investments and equipment upgrades. The company’s advantage lies in its scale and product portfolio: MHI can supply the heavy equipment (steam turbines, generators, ORC units) that modern geothermal plants need, and it has decades of R&D in high‑temperature systems. For example, MHI Power recently won a contract to retrofit the Darajat geothermal plant in Indonesia, replacing aging steam turbines to boost efficiency (a project due by 2026). This shows MHI has the technical heft to upgrade existing fields worldwide.
Perhaps more interestingly, MHI is using its capital to back the geothermal industry’s next frontier. In early 2024, MHI America invested in Fervo Energy, a next-gen geothermal U.S. startup. Through these moves, Mitsubishi is positioning itself as a partner rather than a passive supplier. Since data centers need reliable power with minimal emissions, MHI can offer them combined solutions: its turbines for baseload plants, plus its cutting‑edge EGS investments through Fervo. This strategy gives MHI two avenues of geothermal exposure: core geothermal hardware and innovations in geothermal access.
Fuji Electric (OTCMKTS: FELTY)
HQ: Japan; Supplier of large-scale geothermal power equipment.
Fuji Electric is one of the world’s few suppliers of large-scale geothermal power equipment. Since the 1960s, Fuji has built roughly 60 geothermal turbines worldwide, including the record-setting 140 MW unit. That means Fuji is often in the background of major projects: its turbines spin the steam that powers big geothermal plants. Few companies can match Fuji’s experience delivering high-capacity flash-steam and binary generators that withstand geothermal conditions (high enthalpy steam, corrosive fluids, etc.). For instance, Fuji was the technology partner on Mercury NZ’s and Contact’s recent plants in New Zealand, and it also supplied Turbine-Generators for large projects in the Philippines and Indonesia. This niche leadership is Fuji’s moat: any country or developer planning a large geothermal development will almost certainly consider Fuji’s proven hardware.
Fuji also benefits from relatively stable government and utility orders for geothermal projects, especially in Asia. The barriers to entry here are high, meaning Fuji has limited competitors. Fuji also tends to engage in full-project scope, providing full EPC (engineering-procurement-construction) services. As a result, Fuji often wins bundled contracts that further cements its position, as customers then rely on Fuji’s ongoing maintenance and spare parts.
Devon Energy (NYSE: DVN)
HQ: USA; Oil-gas driller financing enhanced geothermal innovators.
Devon Energy is an oil and gas producer that has emerged as an unconventional geothermal energy stock. The company is applying its drilling expertise and capital to enhanced geothermal projects. Devon was one of the first major E&Ps to invest in this space: in 2023 and early 2024, Devon invested a total of $100 million in Fervo Energy. In essence, Devon is transferring its 50-plus years of experience in oil and gas to geothermal by helping Fervo design and drill twin horizontal wells for heat extraction. This is significant because traditional geothermal wells are mostly vertical and limited; horizontal wells dramatically increase the contact area in hot rock.
Devon’s strategic advantage is its credibility and tools. It boasts world‑class drilling engineers and has deep pockets to scale pilots. Unlike smaller entrants, Devon can field fleets of derricks and service crews instantly. Meanwhile, it has placed its own executives in energy transition, signaling that geothermal fits its long‑term vision. The pay‑off is that if projects like Fervo prove geothermal can be deployed in many new locations, Devon stands to be the go‑to developer or contractor. AI data centers or industrial sites seeking 24/7 carbon‑free power could see Devon as a turnkey geothermal solution.
Private Geothermal Companies to Watch
Venture-backed innovators sit at the bleeding edge: horizontal EGS doublets, closed-loop radiators, geopressured heat-storage hybrids and millimetre-wave drills that vaporise granite. While not publicly traded geothermal energy stocks (at least yet), their technical and commercial milestones serve as bellwethers for the whole sector.
Fervo Energy
HQ: USA; EGS pioneer delivering Google’s first 24/7 geothermal power.
Fervo Energy is a Houston-based pioneer of enhanced geothermal systems (EGS) that applies oil-and-gas drilling know-how to tap previously inaccessible heat reservoirs. Its defining innovation is a “horizontal doublet” approach – drilling two long, curved wells and instrumenting them with fiber-optic sensors – to harvest high-temperature rock deep underground. This lets Fervo yield reliable baseload power on par with fossil plants, a proposition that drew a landmark partnership with Google (the first-ever corporate-backed EGS project) to provide 24/7 carbon-free energy for AI data centers in Nevada. By leveraging existing oilfield skills and digital monitoring, Fervo’s Project Red pilot has proven its technology at commercial scale: a 3.5 MW plant that has run for over a year.
After Project Red, Fervo cut drilling time by 70% at its next site (Cape Station, Utah) and roughly halved well costs (from ~$9.4M to $4.8M per well). These gains have converted interest into concrete commitments: Southern California Edison signed a 320 MW power purchase for Fervo’s 400 MW Cape Station, the largest next-gen geothermal deal globally. Investors have taken note, including a $255M financing round and backing by Devon Energy, reinforcing Fervo’s strong balance sheet.
Eavor Technologies
HQ: Canada; Closed-loop “radiators” for baseload heat almost anywhere.
Eavor Technologies leads the closed-loop geothermal category. Its core innovation, the Eavor-Loop, is a completely self-contained borehole system: an insulated U-shaped or multi-loop network drilled deep underground that circulates fluid in a closed loop to collect heat. Unlike traditional geothermal, it requires no permeability or fluid loss into the formation, so it can work “almost anywhere” on the planet. This always-on, base-load heat capability makes Eavor a natural fit for the surging demand from AI/data centers craving carbon-free 24/7 power. Eavor is on track to complete the world’s first commercial-scale deployment of its technology in Geretsried, Germany – an 8 km multilateral loop project designed to deliver baseload power in mid-2025.
In 2024, Eavor secured €130M in debt (with EIB, JBIC, and others) for the Geretsried plant and drilled record-breaking 8,000‑meter horizontal loops to demonstrate scale. Its on-site organic-Rankine-cycle power plant is now installed and ready to receive heat, validating the predictability of the closed-loop design. Eavor has built a global partner network (including recent deals in Germany and expanding to North America, Japan, etc.) and even developed proprietary planning software (Eavor-Suite) to industrialize its know-how.
GreenFire Energy
HQ: USA; GreenLoop retrofits revive idle wells via closed-loop heat extraction.
GreenFire Energy is a specialist in closed-loop geothermal retrofit systems, branded GreenLoop™. Its technology is designed to revive underperforming geothermal wells or access “stranded” heat reservoirs without pumping fluids into the ground. Essentially, GreenFire installs insulated thermosiphon tubing in wells so that a working fluid circulates and harvests heat without depleting the resource. This approach can tap wells or fields that conventional methods deem uneconomic, such as aging hydrothermal plants or resource “dead zones.” Its GreenLoop™ demos (like a $2.7M CEC-backed pilot at The Geysers) focus on extracting heat from resources and providing clean steam delivery.
GreenFire’s strategy has been validated by partnerships with industry giants. In 2022, Baker Hughes led its Series A round and has since collaborated on joint development of closed-loop projects. Likewise, tubular manufacturer Vallourec and driller Helmerich & Payne also invested in GreenFire. These alliances – plus U.S. DOE grants and lab research – underscore confidence in GreenFire’s business model of low-cost geothermal retrofits. Crucially for investors, GreenFire’s business model has fast payback: it uses proven oil-and-gas techniques and closes loops in days or weeks, so electricity can flow sooner than with a greenfield plant.
Sage Geosystems
HQ: USA; Geopressured wells pair geothermal power with energy storage.
Sage Geosystems has carved a niche with its proprietary geopressured geothermal system (GGS), blending generation and storage. Sage’s GGS drills a single well into a ductile rock formation, then hydraulically fractures and pressurizes it to create a geothermal reservoir. Excess renewable power (e.g. from solar/wind) pumps water into this reservoir under high pressure; when power is needed, valves release the water to run turbines. This yields both reliable baseload power and long-duration energy storage. Sages technology enjoys the synergy between generating firm geothermal energy and providing grid-scale storage at low cost. In 2024, Sage closed $17M to build its first 3 MW commercial “EarthStore” storage project in Texas, targeting ~18–48 hours of flexible power at 2–4¢/kWh.
Sage also captured headlines by signing a landmark offtake: a DOE-linked agreement to supply Meta with up to 150 MW of next-gen geothermal power. This is slated to be the first deployment of its kind east of the Rockies, directly driven by the tech sector’s 24/7 energy demand. Meta’s deal validates Sage’s message that GGS can bring carbon-free baseload to new regions by leveraging hot “dry rock” rather than rare hydrothermal reservoirs.
Quaise Energy
HQ: USA; Gyrotron drilling targets super-hot rock for 10× power per well.
Quaise Energy is developing a truly novel geothermal strategy: it drills incredibly deep (3–20 km) to access super-hot rock everywhere on Earth. Its core innovation is to attach a high-power electromagnetic beam from a gyrotron to a conventional rig, vaporizing rock instead of mechanically cutting it. This allows drilling far deeper to reach temperatures around 500°C. The result is astronomical energy potential: a single “deep geothermal” well could yield roughly 10× the power of a traditional geothermal well at far lower levelized cost. By accessing the planet’s abundant “superhot” depths, Quaise’s millimeter-wave approach could be game changing for geothermal access.
Quaise is still in R&D, but it has garnered strategic commitments. In 2024, it began outdoor field tests in Houston to validate its drilling hardware, planning two yard tests (including a Nabors rig) and a short field drill in an Austin quarry. More significantly, Quaise has teamed with mining giant Nevada Gold Mines (Barrick/Newmont) to retrofit a mine’s power plant with a “deep geothermal” heat source. This joint venture will be the first-of-its-kind pilot to hybridize a fossil-fueled power plant with geothermal heat.