Duisburg/Essen September 19th, 2025 – Factor2 Energy, a German (Duisburg) company with a novel approach to geothermal energy, today announced the successful completion of its seed funding round, raising US$9.1 million in venture capital.
The round was led by At One Ventures, with additional investments from High-Tech Gründerfonds (HTGF), Gründerfonds Ruhr, Verve Ventures and Siemens Energy Ventures. Factor2 Energy will use the seed funding to advance the technological development of its CO₂-based geothermal power generation system and to develop a pilot power plant to demonstrate scalability.
Factor2 Energy is led by Michael Wechsung, Joerg Strohschein and Felix Boehmer who all worked together at Siemens Energy. There they invented a new, economically superior method to harness geothermal energy by utilizing CO₂ as the primary working fluid in the geothermal cycle, replacing water or brine.
How it Works: Clean Energy from Stored CO₂ – Safe, Scalable, and Sustainable
The technology can be deployed at either natural CO2 Reservoirs or at reservoirs designated for Carbon Capture and Storage. The (naturally occurring or captured) CO₂ is injected into deep, porous geological formations, where it is securely stored. As it absorbs geothermal heat from the surrounding rock, its density decreases, initiating a buoyancy-driven circulation known as the thermosiphon effect. As a result, the CO₂ rises naturally to the surface via production wells, eliminating the need for subsurface pumps and significantly reducing parasitic energy consumption and mechanical complexity.
At the surface, the heat is converted into electricity using a direct driven CO₂ turbine system. After expansion, the CO₂ is cooled, reinjected into the reservoir, creating a closed cycle that enables continuous power generation while maintaining long-term CO₂ storage.
Compared to conventional water-based geothermal systems, this approach can achieve up to twice the power output under similar geological conditions, while requiring lower capital expenditures (CAPEX).
“Our approach enables emission-free, efficient, and baseload-capable electricity production, which is ideal for traditional oil and gas companies looking to diversify their operating assets” said CEO and co-founder Felix Boehmer. “And in fact, the entire system leverages proven technologies from the oil and gas sector, with its long history of drilling and geologic expertise.“
Siting Simplicity: More Location Options and Operational Ease
Besides delivering reliable, 24/7 green power, the use of CO₂ enables access to a broader range of geological sites, unlocking heat from locations unsuitable for conventional geothermal systems.
Using CO₂ allows Factor2 Energy to tap into shallower and cooler geothermal sites, reducing drilling costs and expanding the range of viable power plant locations. The system operates efficiently where conventional geothermal fails, offering competitive Levelized Cost of Electricity. It also eliminates the need for secondary fluids or complex binary systems, simplifying operations. And, by leveraging both geological formations designated for CO₂ storage (CCS) and natural CO₂ reservoirs, Factor2 Energy can transform these into active energy assets.
Helen Lin, Partner at At One Ventures comments: “As a cornerstone for enabling broader electrification, the need for cost-effective baseload power has never been more urgent. The fluid physics of CO₂ as a geothermal working fluid enables a 2x increase in power output while operating at the same depths/temperatures as conventional geothermal, translating to efficiencies in both capex and opex. These technoeconomics combine to form a favorable LCOE at sites that would previously have been economically unviable. We are excited to support Factor2 to bring this crucial technology to market to unlock the potential of geothermal as a more prevalent source of green baseload”.
“We invested in Factor2 Energy because the team has developed a technology that significantly expands the global potential of geothermal energy while transforming existing CCS infrastructures into productive power plants. The successful proof of concept in a challenging geological environment demonstrates the robustness and scalability of the approach. We are convinced that Factor2 Energy is thus in a key position to actively shape the energy transition. Above all, however, we see founders whom we trust to take on this demanding challenge thanks to their expertise and entrepreneurial spirit.” said Jan Gräfe, Managing Partner at Gründerfonds Ruhr.