Fervo's Cape Station Begins Commercial Operation With 33 MW of Next-Generation Geothermal Power
- What happened: The first facility at Fervo's Cape Station entered commercial operation on September 30, delivering 33 MW net and meeting its contract requirements.
- Why it matters: Heat collected through artificial underground flow paths has now been connected to revenue at a newly built power plant.
- What to watch next: About 100 MW planned for early 2027, the 500 MW plan for 2028, and whether temperature and flow rates hold up over long-term operation.
On October 1, U.S.-based Fervo Energy announced that the first facility at Cape Station, its next-generation geothermal power plant under development in Beaver County, Utah, entered commercial operation on September 30. Net output, after subtracting the electricity used within the plant, is 33 MW. Fervo says this meets the requirements of its power purchase agreement (PPA) and that revenue from electricity sales has begun. A technology that creates artificial water pathways in hot rock has started operating as an electricity business at a newly built plant.
Still, what is running now is only one part of the planned 500 MW project. The steps of extracting heat from underground, sending it to surface equipment, and selling power under contract are now connected. What remains is whether the same facilities can be built repeatedly at lower cost, and whether the underground flow of heat and water can be sustained over a long period.
Separating the 33 MW operating record from the 500 MW plan
Cape Station synchronized with the grid on September 24 and declared commercial operation six days later, on September 30. The contractual target date was October 1, so it arrived one day early. Fervo positions this as the first time a newly developed enhanced geothermal system (EGS) has achieved contractual commercial operation. The 33 MW cited in the October 1 announcement is not the generator's gross output but a figure after deducting the plant's own power consumption.
The company also operates Project Red, a commercial demonstration facility in Nevada that has supplied power since 2023. The change this time is not that EGS produced electricity for the first time, but that the experience has been carried over to a larger, newly built plant and brought to the point of meeting a contractual output requirement.
Breaking Fervo's October 1 announcement into achieved status and plans clarifies what each capacity figure means. The 33 MW in commercial operation, the roughly 100 MW of Phase I, and the 500 MW total in 2028 represent, respectively, an achievement, a staged target, and an expansion plan.
| Development stage | Capacity | Status as of the October 1 announcement |
|---|---|---|
| Phase I, first facility | 33 MW net | Entered commercial operation September 30; revenue under way |
| Phase I overall | About 100 MW | Made up of three 33 MW facilities; the remaining two are expected to be in commercial operation by January 1, 2027 |
| Phase II | Additional 400 MW | Under construction; commercial operation planned for 2028 |
| Phases I and II combined | 500 MW planned | About 100 MW plus an additional 400 MW; not a record of full capacity in operation |
Capacities and statuses are based on the same announcement. Three 33 MW facilities would total 99 MW, but Phase I is given as the company's official approximate figure of "about 100 MW." The 500 MW figure is a planned value obtained by adding 400 MW to that roughly 100 MW; it does not indicate annual electricity generation or output sustained over the long term.
Fervo calls a development unit combining a group of wells and power generation equipment a "GeoBlock." According to the company, building the first GeoBlock's generation facility and completing commissioning took 23 months. That period differs from the number of years of overall development, which begins with surveying land and underground resources. Standardizing equipment and applying experience to the next build is the way to scale up.
Collecting heat underground and spinning an organic fluid on the surface
Conventional geothermal power requires three conditions: underground heat, fluids such as water, and rock with properties that let those fluids pass through. According to the U.S. Department of Energy's explanation, EGS is used where the rock is hot but lacks sufficient water or natural pathways. Fluid is injected underground in a controlled manner to create new fractures or open existing ones, forming a reservoir through which water can flow.
Water picks up heat as it passes through the rock fractures and then returns to the surface. The oil and gas industry technologies Fervo adapts include not only drilling deep wells but also creating flow paths along the horizontal sections of those wells. Compared with the conventional approach of looking for places where natural hot water is easy to use, locations that have heat but too few water pathways can also become development targets.
For surface power generation, the plant uses an organic Rankine cycle (ORC) system supplied by Turboden, part of the Mitsubishi Heavy Industries group. This is a type of binary power generation in which a heat exchanger transfers heat from the hot fluid coming from underground to a separate working fluid. Fervo's August business report also described the process of connecting wells to the power equipment and sending geothermal fluid through heat exchangers to drive the turbines.
According to Turboden's explanation of the principle, an ORC vaporizes an organic fluid instead of water steam and uses that vapor to drive a turbine and generator. The used organic fluid is cooled and condensed, then circulated again. In other words, the path by which underground water carries heat and the path of the fluid that spins the turbine on the surface are linked through the heat exchanger.
This closed circulation on the surface is a different matter from "closed-loop geothermal," in which fluid is passed through sealed pipes underground. In Cape Station's EGS, water collects heat as it passes through rock fractures. Closed-loop geothermal circulates fluid inside underground pipes, so it does not rely on a network of rock fractures. Both use heat, but they differ in where the water travels underground.
Looking at EGS and ORC together shows what Cape Station has newly established. On the surface, it uses existing power generation technology; underground, it delivers the necessary heat through human-made flow paths. The plant's output is obtained only when both work.
What the 21-day drilling covers, and what $5,500 per kW means
In its second-quarter 2026 business report, Fervo explained that it finished drilling "Sawtooth 7," a well for Phase II, in 21 days. The well uses its third-generation design, "Fervo 3.0," which has a longer horizontal section and a larger-diameter casing to protect the well, aiming to increase output per well.
According to CEO Tim Latimer's July 16 design explanation, Sawtooth 7 has a length of 19,448 feet, a horizontal section of 7,500 feet, and a resource temperature of 460 degrees Fahrenheit. Converted to metric and Celsius, that is about 5,928 m, about 2,286 m, and about 238°C. Whereas the previous generation had a 5,000-foot horizontal section and 7-inch pipe diameter, Sawtooth 7 extends the horizontal section and widens the pipe diameter to 8.625 inches.
The roughly 5.93 km is the total length measured along the well. The second-quarter report presents it as "measured depth," not a figure for drilling vertically to 5.93 km underground. For a well that curves horizontally, the total length of the well and the depth below the surface must be distinguished. The 21 days is also the period from the start of drilling to reaching the planned well length; it is not the full timeline through to commercial operation, which includes well completion and construction of power equipment.
Lengthening the horizontal section may expand the underground area that receives heat. A larger well leads to a design that can handle more fluid. Fervo's aim is not only to shorten drilling days but also to increase the output obtained from each well and lower the cost of preparing the same generation capacity. However, the effect of the larger design will need to be evaluated together with actual flow rates, temperatures, and required pumping power.
The cost the company anticipates for Phase II is $5,500 per kW of generation capacity. It has also set a longer-term target of $3,000. This is an indicator of the cost of building the facilities, not the price at which 1 kWh of electricity is sold. The $5,500 is also a forward-looking estimate, not a final cost announced as confirmed after commercial operation.
Underground heat has no daily fuel purchase price as gas-fired plants do, but money must be invested up front in wells and equipment to extract it. Faster drilling is therefore a factor that can improve profitability, but it alone does not determine whether cheap electricity can be supplied. To recover construction costs, the plant must keep running and secure the volume of electricity it sells.
An operating design that monitors earthquakes and halts work
At Cape Station, earthquakes associated with injecting fluid underground are monitored, and work is stopped depending on the magnitude detected. According to the on-site seismic monitoring report Fervo released on June 29, from November 1, 2025 through April 30, 2026, there were 36 events of magnitude 2 to 3 classified as "yellow" under the company's traffic-light-style management criteria. The largest was ML 2.87 on April 5, and no events were classified as "red," the report says.
The company explains that when it detected an event above magnitude 2, it began a six-hour work stoppage within 30 minutes. This report covers the underground development period before commercial operation, and it does not mean the power plant was shut down 36 times. It shows that procedures for detecting earthquakes and halting work such as injection were actually built in.
The U.S. Lawrence Berkeley National Laboratory also took part in developing the monitoring equipment. According to the laboratory's January 23 announcement, seismometers were installed at Cape Station at a depth of about 2,132 m in an environment of about 170°C, continuously recording signals from microearthquakes. Technology that measures while withstanding underground heat supplements observations from the surface.
Recording microearthquakes spans both risk management and resource development. If it is possible to estimate how far fractures grow and how the water pathways change, that provides material for adjusting injection and circulation. The laboratory aims to use detailed observations to control reservoir development and reduce the possibility of large induced earthquakes felt at the surface. The absence of any "red" events over the past six months cannot be read as a guarantee of future safety.
The next test: sustaining heat and flow while continuing to sell power
Fervo explains that it is advancing development from locations with favorable geological conditions, such as large temperature increases with depth. Latimer's design explanation likewise says that using geothermal power cheaply everywhere will require technology development to reach deeper, hotter resources. Cape Station's commercial operation does not show that the same cost and performance can be reproduced in every region.
According to the U.S. Department of Energy's explanation of subsurface resources, rock stress, temperature, and water flow affect one another, and chemical changes are added as well, so technology for predicting reservoir response has room for improvement. Operators need to measure flow rate, pressure, and temperature so they can respond when underground conditions change. Even after heat extraction begins, the underground does not necessarily stay in the same state.
This is the part that links the start of commercial operation to evaluation as a long-term power business. Can wells keep delivering sufficient temperature and flow? Will the power needed for circulation rise? How much electricity can be sold, including shutdowns and repairs? The 33 MW output alone cannot yet answer these questions.
On the demand side, there are buyers waiting for expansion. The 396 MW power purchase agreement with Google that Fervo announced on September 1 covers the Cape Station expansion planned for 2028 and is intended to supply power to data centers under consideration in Utah. Conditions such as technical feasibility and approvals remain for the data center plans. The current 33 MW facility is not already supplying that 396 MW.
The remaining Phase I facilities planned for early 2027 and Phase II in 2028 are the next stage for confirming whether construction can be repeated. And as operating records accumulate after startup, including temperature, flow rate, and shutdowns, it will become possible to judge how far a power source that uses underground heat can support always-on computing infrastructure, based on firmer evidence than planned capacity.