By Phil Cruver Co-founder and CEO of Geo2Watts™
Europe has become a center of innovation for high-temperature heat pumps, with manufacturers, research organizations and industrial users increasingly focused on replacing fossil-fuel boilers and decarbonizing process heat. The IEA Heat Pumping Technologies Technology Collaboration Program’s Project 68, launched in 2025, reflects the growing maturity of this sector. Its objective is to accelerate the uptake of industrial high-temperature heat pumps (HTHPs), and the program has already mapped more than 55 technology suppliers and over 40 demonstration cases. That work is important. But it may also be preparing the heat-pump industry for a market that extends well beyond industrial heat.
A new application emerging in the United States could use HTHP technology not simply to deliver heat, but to store electricity as thermal energy and later convert that stored energy back into dispatchable electricity. If successful, reversible high-temperature heat pumps (RHTHPs) could become a core component of a new category of long-duration energy storage and provide heat-pump manufacturers around the world with access to the rapidly expanding U.S. electricity market.
America’s new electricity problem
For much of the past two decades, electricity demand in the United States was relatively flat. That period is ending. Artificial intelligence, hyperscale data centers, semiconductor facilities, electrification and the on-shoring of manufacturing are combining to create levels of electricity-demand growth that the U.S. power industry has not experienced for decades. The U.S. Department of Energy identifies AI, data-center expansion, domestic manufacturing and electrification as principal drivers of a return to sustained electricity-demand growth.
Data centers illustrate the scale of the challenge. Lawrence Berkeley National Laboratory estimates that U.S. data centers consumed approximately 176 TWh of electricity in 2023, equivalent to about 4.4% of total U.S. electricity consumption. By 2028, consumption could rise to between 325 and 580 TWh, representing approximately 6.7% to 12% of all U.S. electricity consumption. That corresponds to estimated data-center power demand of roughly 74 to 132 GW.
And data centers are only part of the story. Berkeley Lab specifically identifies on-shoring of manufacturing, industrial electrification, hydrogen production and other forms of electrification as contributors to a much larger long-term increase in U.S. electricity requirements. This creates two challenges simultaneously.
America needs substantially more electricity, but it also needs electricity when customers require it, not merely when renewable generation happens to be available. That difference creates an enormous opportunity for energy storage.
Moving the heat pump from heat production to energy storage
Geo2Watts is developing the Borehole Battery™ Platform, or BBP, around a different application for HTHP technology and the concept is straightforward. During charging, electricity powers a HTHP that moves thermal energy from a lower-temperature source into an underground thermal-energy-storage system. The heat is stored inside closed-loop, cased-and-cemented boreholes constructed from repurposed oil and gas wells. When electricity is required, the thermal energy is recovered and used through an expansion and generation system to return AC electricity to a grid or behind-the-meter customer.
Importantly, this is not geothermal energy. The wells do not extract naturally occurring underground heat but are storage vessels for heat deliberately placed underground during the charging cycle. The distinction is important for the heat-pump industry. Most HTHPs being commercialized today have been designed around a relatively familiar objective: supply industrial process heat more efficiently and with lower emissions than boilers.
The BBP asks a different question: Can the same fundamental heat-pump technology become part of a reversible machine that charges thermal storage when electricity is abundant and returns electricity when it is scarce and valuable? That turns the HTHP from an industrial heating appliance into part of a power-generation and energy-storage system.
Why the COP matters
The attraction of the heat pump is rooted in one of its defining characteristics: coefficient of performance (COP). A heat pump does not convert one unit of electricity into one unit of heat. It uses electricity to move thermal energy. Consequently, an HTHP operating at a COP above 3 can transfer more than three units of thermal energy into storage for each unit of electrical energy consumed.
That does not mean the complete electricity-storage system achieves a COP of three. Electricity must subsequently be recovered from the stored thermal energy, and overall AC-to-AC round-trip efficiency depends on the entire thermodynamic cycle, including compressor performance, heat exchangers, storage losses, pumps, parasitic loads and expansion efficiency.
But the heat pump’s ability to move substantially more thermal energy than the electrical energy supplied to its compressor is precisely what makes the architecture interesting. The engineering challenge is therefore no longer simply to build the most efficient heat pump. It is to optimize a reversible thermal-to-power system.
The opportunity for a reversible high temperature heat pump (RHTHP)
The long-term objective is a purpose-built RHTHP optimized for both halves of the storage cycle. In charging mode, the machine operates as a HTHP moving heat into thermal storage. In discharge mode, the architecture uses the stored thermal energy to drive an expander-generator and produce electricity.
Geo2Watts’ present system architecture integrates compressors, expanders, generators, recuperative heat exchangers, pumps, valves and controls with the changing thermal behavior of the underground storage system. Unlike an HTHP designed around one stable industrial process temperature, an energy-storage machine must operate across a changing thermodynamic envelope.
Storage temperature changes during charging and discharge. Electricity prices change and grid requirements change. The machinery must accommodate startup, shutdown, part-load operation, turndown and transitions between charge, standby and generation. That creates an engineering opportunity for manufacturers already developing compressors, expanders, and HTHPs for industrial applications.
European manufacturers have spent years solving many of the difficult problems involved in higher discharge temperatures, refrigerant selection, compression architectures, heat exchangers and large industrial machines. Project 68 is helping establish exactly this kind of technical and commercial ecosystem. Its current work involves manufacturers, end users, universities and research organizations and is intended to move industrial HTHPs from demonstrations toward broader deployment. The next market may be electricity.
America could be the large new market
The scale of U.S. electricity demand makes this particularly significant. A data center does not merely need inexpensive electricity. It requires dependable electricity around the clock. Likewise, advanced manufacturing plants cannot base production schedules solely on when solar or wind resources are available. That means a rapidly expanding renewable generation fleet increasingly needs to be paired with storage capable of shifting large quantities of energy from periods of abundance into periods of high demand.
The U.S. Department of Energy specifically identifies onsite generation, energy storage and long-duration energy storage among the technologies that can help accommodate rapidly increasing data-center demand. For a future RHTHP manufacturer, that potentially changes the addressable market dramatically. Instead of selling equipment primarily according to the number of factories requiring process heat, manufacturers could ultimately participate in a market measured against hundreds of gigawatts of new generation and storage infrastructure.
And unlike many greenfield energy projects, the BBP is intended to use existing industrial infrastructure wherever possible. America has hundreds of thousands of oil and gas wells approaching or already at the end of productive life. The BBP is designed to repurpose technically suitable wells as thermal storage assets while potentially reusing industrial sites, substations and existing grid connections. That introduces another unusual characteristic: storage can be distributed and dispatchable, located near industrial customers and existing electrical infrastructure rather than necessarily being concentrated in large standalone storage projects.
Can a RHTHP Compete with a Battery Energy Storage System (BESS)?
Lithium-ion battery energy storage systems have become the dominant technology for short-duration grid storage and will remain important. But the competitive environment changed significantly on August 26, 2026, when President Trump declared a national emergency concerning foreign supply of equipment used in the U.S. bulk-power system.
The Executive Order goes beyond the sourcing restrictions created by the One Big Beautiful Bill Act. Prohibited Foreign Entity (PFE) and Foreign Entity of Concern (FEOC) requirements primarily affect eligibility for federal clean-energy incentives. The new order introduces a broader national-security test, allowing the Federal Government to prohibit certain transactions involving foreign-produced bulk-power equipment associated with Covered Foreign Entities when unacceptable cybersecurity, sabotage, remote-access or supply-chain risks are identified. The order specifically encompasses BESS, grid-connected inverters, transformers, generators, turbines, industrial controls and associated software.
For storage developers, equipment sourcing may therefore become more than a tax-credit issue. In some circumstances, it could determine whether equipment can be acquired, installed or remain connected to critical U.S. power infrastructure. That creates an opening for alternative long-duration storage architectures designed to reuse existing wells, industrial sites, substations and electrical infrastructure while returning synchronous AC power through an expander-generator rather than relying on a battery inverter for discharge. A future RHTHP built around secure U.S.-manufactured compressors, expanders, generators, heat exchangers and controls could combine long-duration storage with brownfield infrastructure America has already built and paid for.
For applications requiring ten or more hours of storage, developers may increasingly evaluate more than installed cost and round-trip efficiency. System lifetime, degradation, storage duration, cybersecurity, domestic manufacturing, supply-chain resilience, synchronous generation and reuse of existing infrastructure could all become important measures of value. If RHTHPs achieve the required efficiency, reliability and economics, brownfield RHTHP-based storage could offer something increasingly valuable: dispatchable and distributed electricity built around secure infrastructure already operating on American soil.
Phil Cruver is a Co-founder and CEO of Geo2Watts™. Previously, he was the Founder and CEO of Catalina Sea Ranch, the first aquaculture facility in U.S. Federal waters developed six miles offshore California. Phil was also the founder of five additional start-up companies and recently served as Principal Investigator for over $1.2 millions of Federally funded R&D projects. He is also a wind energy pioneer who founded International Dynergy, a publicly traded company that installed 500 wind turbine generators in Palm Springs, California.
