Exowatt
| Company type | Private |
|---|---|
| Industry | Renewable energy |
| Founded | 2023 |
| Founder | Hannan Happi, Jack Abraham |
| Headquarters | Miami , United States |
Key people | Hannan Happi (CEO), Jack Abraham (Chairman) |
| Products | Modular thermal energy storage systems (Exowatt P3) |
Exowatt is a U.S.-based renewable energy firm headquartered in Miami, Florida, established in 2023 by Hannan Happi and Jack Abraham. The company develops modular thermal energy storage solutions that deliver reliable renewable power on demand, primarily serving data centers and other high-energy commercial sectors.
The company's premier offering, the Exowatt P3, is a modular solar thermal system capable of providing up to 24 hours of dispatchable electricity daily. It harnesses solar energy through advanced lenses, stores the captured heat in a long-duration thermal battery, and generates electricity via a heat engine as required. By April 2025, Exowatt had secured $90 million in venture funding.
Corporate history
Exowatt was launched in 2023 by CEO Hannan Happi and Chairman Jack Abraham to meet the growing energy requirements of AI technologies and data centers with dependable renewable baseload power. Happi brings experience from Siemens, General Electric, and Tesla, while Abraham also leads Atomic—where Exowatt was initially developed—and co-founded ventures such as Hims & Hers Health.
Following several development cycles, the company finalized its thermal storage technology. Exowatt publicly emerged from stealth mode in April 2024 after raising a $20 million Seed round led by Andreessen Horowitz (a16z), Atomic, and OpenAI CEO Sam Altman. The initial capital supported platform development and early market entry. Katherine Boyle, General Partner at a16z, emphasized Exowatt’s commitment to U.S.-based manufacturing and enhancing energy infrastructure resilience as critical factors for investment.
In September 2024, Exowatt introduced the P3 system at the RE+ clean energy conference held in Anaheim, California, attracting investors including actor Leonardo DiCaprio. By the end of 2024, the company reported a backlog of customer orders exceeding 85 GWh.
In April 2025, Exowatt completed a $70 million Series A financing round led by Felicis Ventures—comprising $35 million in equity and $35 million in debt from HSBC Innovation Banking and collaborators—bringing total investment to $90 million. Other participants throughout funding rounds included 8090 Industries, Starwood Capital, MCJ Collective, MVP Ventures, GOAT VC, StepStone Group, Climate Capital, Overmatch Ventures, Protagonist, and Leonardo DiCaprio. These funds are intended to facilitate commercial rollouts beginning in 2025.
Technology
The Exowatt P3 is a modular energy system engineered to fit within the dimensions of a standard 40-foot shipping container. It integrates three core functions: solar energy capture, thermal energy storage, and on-demand electricity generation.
Solar collection
Departing from conventional photovoltaic (PV) panels that convert sunlight directly into electricity, the P3 employs specialized Fresnel lenses to concentrate solar rays into heat. This method aligns with concentrated solar power (CSP) principles but is optimized for modularity and scalability to serve AI-powered data centers.
Thermal storage
The solar heat collected is stored within a thermal battery composed of clay or ceramic composite materials that maintain consistent performance without involving phase changes or chemical reactions. This contrasts with molten salt storage used in traditional CSP plants or phase-change materials applied elsewhere.
Exowatt emphasizes that its thermal storage technology utilizes simpler and more cost-effective materials than electrochemical batteries. Additionally, it experiences minimal degradation over time compared to lithium-ion batteries that suffer capacity loss after repeated charging cycles.
Power generation
The stored thermal energy is transformed back into electrical power through a heat engine, most likely a Stirling engine.[1] This technology facilitates dispatchable electricity production independent of solar availability.[2]
Exowatt’s solution does not depend on rare earth elements or intricate international supply chains, setting it apart from many lithium-ion battery technologies.Cite error: The opening <ref> tag is malformed or has a bad name Their system incorporates power electronics and control mechanisms designed to integrate seamlessly with current electrical grids.[3]
As of September 2024, Exowatt announced initial electricity production costs slightly below $0.04 per kWh, with a long-term objective to reduce costs to $0.01 per kWh or less, according to Mercom Capital Group.Cite error: The opening <ref> tag is malformed or has a bad name The company highlights its commitment to U.S.-based manufacturing using domestically sourced components.[4]
Market focus and industry context
Exowatt aims to serve the energy demands of AI-intensive data centers along with other commercial and industrial sectors requiring substantial power.Cite error: The opening <ref> tag is malformed or has a bad name Their technology is positioned to address the escalating energy consumption driven by expanding computing infrastructure, particularly for AI workloads.[5]
Data center industry dynamics
pv magazine reports that energy usage in Data center operations is projected to increase significantly due to AI adoption, intensifying the need for dependable power solutions. Capacity Media’s coverage of Exowatt underscores the stringent reliability standards maintained by traditional data centers.
Numerous sources highlight regional power limitations, prompting technology companies to explore behind-the-meter generation and storage options to reduce carbon footprints while ensuring consistent energy supply.
Market positioning
Exowatt has seen growing customer demand, with backlog volumes climbing from over 500 MW in April 2024 to upwards of 1.2 GW by September 2024, later quantified as 85 GWh in late 2024 and exceeding 90 GWh by April 2025, based on company statements and media reports. These orders originate from data centers, energy developers, and hyperscale operators across the United States.
The firm planned an initial installation at a West Texas site dedicated to cryptocurrency mining activities. Exowatt presents its technology as complementary to other renewable energy systems and is often compared with thermal battery startups like Antora Energy and Rondo Energy, though it employs distinct technical methods.
Industry commentary characterizes Exowatt’s approach as "reviving legacy technologies," such as Fresnel lenses and thermal batteries ("hot bricks"), focusing on enabling round-the-clock renewable power availability. Nonetheless, Latitude Media raised questions about scalability challenges, land requirements, geographic limitations, and noted that much of the backlog consists of preliminary agreements rather than confirmed contracts.
Business model
Exowatt concentrates on delivering combined hardware and software solutions directly to sectors with high energy consumption, including energy developers and data center operators.
The company emphasizes domestic production and sourcing strategies aligned with national infrastructure resilience objectives, as highlighted by Katherine Boyle from Andreessen Horowitz.
See also
- Solar energy
- Concentrated solar power
- Thermal energy storage
- Data center
- Environmental impact of artificial intelligence
- Dispatchable generation
References
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