Last Energy
| Company type | Private |
|---|---|
| Industry | Nuclear power |
| Founded | 2019 |
| Founder | Bret Kugelmass |
| Headquarters | Washington, D.C. , United States |
Area served | United States, Europe, Latin America, Asia |
Key people | Bret Kugelmass (Founder) |
| Products | Micro-modular nuclear power plants (PWR-20) |
| Website | lastenergy |
Last Energy is a U.S.-based commercial developer specializing in micro-modular nuclear power plants. Established in 2019 by Bret Kugelmass, it originated as a spin-off from the Energy Impact Center, a research organization dedicated to clean energy innovation.
The company focuses on producing 20 MWe nuclear microreactors, notably the PWR-20 model—a compact modular reactor built from factory-fabricated rectangular units utilizing pressurized water reactor technology. Last Energy provides comprehensive project services encompassing design, construction, financing, operations, and eventual decommissioning. Their approach aims to shorten development timelines and lower expenses associated with nuclear projects to promote wider availability of clean and cost-effective energy. Based in Washington, D.C., the firm maintains additional offices in Romania, Poland, and the United Kingdom.
History
Bret Kugelmass founded the Energy Impact Center (EIC) in 2017 and initiated the Titans of Nuclear podcast in 2018 to discuss nuclear energy challenges. Through this work, he pinpointed construction delays and escalating costs as major obstacles hindering new nuclear initiatives.
In 2019, EIC launched the Nuclear Energy Grand Challenge to encourage innovative business ideas from students. Later that year, Kugelmass formed Last Energy as a commercial venture. The following year, EIC introduced OPEN100—an open-source platform providing free nuclear plant design blueprints aimed at simplifying construction processes and targeting a 100-fold increase in nuclear capacity by 2040. Last Energy raised $20 million in Series A funding during 2020, led by Gigafund.
Responding to the European energy crisis caused by Russia’s invasion of Ukraine, Last Energy announced a demonstration project with Romania’s RATEN in 2022. The company also entered into agreements with Poland’s Enea Group to develop microreactors supporting Poland’s goal of carbon neutrality by 2050. Furthermore, it partnered with the Legnica Special Economic Zone to deploy ten microreactors for industrial power generation.
Last Energy continues to expand partnerships throughout Europe, Latin America, and Asia. In March 2023, it secured contracts totaling $18.9 billion for 34 reactors across Europe. That year included public presentations of reactor prototypes in Poland and at SXSW, highlighting efforts to reduce costs and accelerate delivery schedules. By early 2024, contractual commitments had grown to 51 units valued at $32 billion across Europe. The company also exhibited its reactor module at industry events in Houston and Washington, D.C., targeting data centers that comprise roughly half of its commercial client base.
In mid-2024, Last Energy collaborated with NATO’s Energy Security Centre of Excellence to investigate micro-nuclear solutions for military installations. It completed a $40 million Series B funding round early that year, bringing total investments raised since inception to $64 million.
October 2024 saw Last Energy reveal plans for a £300 million investment to construct four microreactors on a former coal-fired power station site in South Wales intended to supply regional industrial demand. Its Project Quantum was selected by the European Commission for advanced development support through the European Industrial Alliance on Small Modular Reactors.
The U.S. Department of Energy designated Oak Ridge National Laboratory to assist Last Energy with material characterization under an Inflation Reduction Act-funded initiative. Meanwhile, the Export-Import Bank of the United States expressed willingness to provide $103.7 million in debt financing for Last Energy’s inaugural Welsh microreactor.
In early 2025, the UK’s Office for Nuclear Regulation accepted Last Energy’s South Wales project into site licensing—the first licensing process for a new commercial nuclear reactor since 1978—marking a pivotal achievement in the company’s expansion within the market.
Design and construction
The initial offering from the company, the PWR-20, is a 20 MWe micro-modular nuclear power system designed as modules that fit within a standard shipping container. This modular approach allows for factory fabrication, transportation via truck, and onsite installation as a "plug-and-play" solution.
Last Energy incorporates methodologies from the oil and gas sector to streamline expenses and shorten delivery schedules for nuclear facilities. The PWR-20 is intended to be situated alongside industrial consumers such as manufacturing plants, steel production facilities, and data centers, enabling direct energy supply that circumvents grid limitations. Utilizing readily available supply chains, the company is capable of delivering a complete plant within a 24-month timeframe.
When fully installed, the PWR-20 occupies an area comparable to a football field. Distinct from many nuclear technology developers, Last Energy opts not to depend on government funding for its projects.
The PWR-20 features a 20 MWe (80 MWth) single-loop pressurized water reactor operating continuously at 300°C. It runs on conventional pressurized water reactor fuel enriched to 4.95% and utilizes closed-cycle air cooling.
The use of air cooling removes the necessity for nearby water sources, making the system ideal for widely distributed energy consumers. Additionally, the company can deploy multiple units in tandem to adjust power output based on client demands.