# Last Energy

> Last Energy is a US-based developer of factory-built micro modular nuclear power plants. Its flagship PWR-20 is a 20-megawatt pressurized water reactor assembled from truck-shippable modules and delivered as a turnkey, build-own-operate service. Rather than selling reactors, Last Energy sells electricity and heat under long-term power purchase agreements, targeting data centers and energy-intensive industries that need reliable, carbon-free baseload power without financing or operating a plant themselves.

- **Founded:** 2019
- **Headquarters:** Austin, Texas, United States
- **Founders:** Bret Kugelmass (Founder & CEO)
- **Team size:** ~67 employees
- **Products:** PWR-20, PWR-5, Nuclear-as-a-Service (build-own-operate)
- **Notable:** Closed an oversubscribed $100M Series C in December 2025, bringing total funding to roughly $164M., Signed power purchase agreements for 34 PWR-20 units with industrial partners in Poland and the UK, valued in press reports at up to $18.9 billion., Entered the UK nuclear site licensing process - the first new commercial reactor site to do so since 1978.

## Products & services

- **PWR-20** — A 20 MWe (80 MWth) single-loop pressurized water reactor delivered as a fully modular, factory-built micro power plant. Components ship by truck, the plant fits within roughly a football-field footprint, uses standard 4.95% enriched fuel, and targets a 24-month delivery timeline.
- **PWR-5** — A 5-megawatt scaled-down version of the PWR-20 used for pilot deployments, including the Texas A&M-RELLIS project to demonstrate low-power criticality and later grid electricity generation.
- **Nuclear-as-a-Service (build-own-operate)** — Last Energy designs, finances, builds, owns, and operates the plant, selling power and heat to customers under long-term power purchase agreements so customers never develop, finance, or operate the asset themselves.

## Achievements

- Closed an oversubscribed $100M Series C in December 2025, bringing total funding to roughly $164M.
- Signed power purchase agreements for 34 PWR-20 units with industrial partners in Poland and the UK, valued in press reports at up to $18.9 billion.
- Entered the UK nuclear site licensing process - the first new commercial reactor site to do so since 1978.
- Completed a Preliminary Design Review milestone with the UK Office for Nuclear Regulation in 2025.
- Announced its first US reactor deployment, a PWR-5 pilot with the Texas A&M University System.
- Received a $103.7M letter of interest from the U.S. Export-Import Bank.

## Latest updates

- **2025-12** — Closed $100M oversubscribed Series C led by the Astera Institute, pushing total funding to about $164M.
- **2025-08** — Earned a Preliminary Design Review milestone with the UK Office for Nuclear Regulation for the PWR-20.
- **2025-01** — Accepted a National Grid connection offer for its first South Wales unit at the former Llynfi coal plant site.
- **2025** — Announced PWR-5 microreactor pilot with the Texas A&M University System at RELLIS, targeting criticality by mid-2026.

## Links

- Website: https://lastenergy.com
- LinkedIn: https://www.linkedin.com/company/lastenergy
- Twitter/X: https://twitter.com/lastenergy

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Profile page: https://yespress.io/last-energy
Published by YesPress — https://yespress.io
Last updated: 2026-06-14