> ## Content Index > Fetch the complete content index at: https://atomicinsider.com/llms.txt > Use this file to discover other available public pages before exploring further. # Last Energy - URL: https://atomicinsider.com/article/last-energy/ - Published: 2026-10-19T10:47:13.000Z - Updated: 2026-10-30T09:35:04.000Z - Description: Last Energy is developing the PWR-20 microreactor, with plans to supply clean electricity directly to customers under long-term agreements. Its proposed European projects include an 80 MWe development in Wales. - Author: Artjoms Krizanovsksis - Tags: Companies to Know, Issue 01 ## What they do Last Energy is developing the PWR-20, a pressurised water microreactor designed to generate approximately 20 MWe of electricity from 80 MWth of thermal power. Rather than selling reactors to utilities or industrial operators, the company aims to develop, finance, build, own and operate its plants, supplying electricity directly to customers under long-term contracts. The PWR-20 is designed to use conventional low-enriched uranium fuel. Last Energy proposes manufacturing reactor modules off-site for assembly at customer locations, with the aim of reducing construction work and associated costs. ![Rendering of a Last Energy PWR-20 plant](https://storage.ghost.io/c/c3/97/c397e43d-60f4-42e6-acb3-674aa64291df/content/images/2026/10/lastenergy-pwr20-plant.webp) Image: Last Energy ## Where they are Last Energy has proposed deploying four PWR-20 units at the former Llynfi Power Station site in Bridgend County Borough, Wales. The project entered the UK nuclear site-licensing process in January 2025 and completed a Preliminary Design Review in June 2025\. Further regulatory approvals are required before construction. ![Rendering of a multi-unit Last Energy site with grid connection](https://storage.ghost.io/c/c3/97/c397e43d-60f4-42e6-acb3-674aa64291df/content/images/2026/10/lastenergy-llynfi-site.webp) Image: Last Energy The company has also announced commercial agreements with prospective customers and partners in Poland and Romania. In the United States, Last Energy is pursuing a separate PWR-5 pilot project with Texas A&M University, intended to advance its reactor development programme. As of October 2026, Last Energy has not yet constructed or operated a PWR-20 reactor. ## What’s next The Welsh project provides an opportunity to assess Last Energy’s progress towards deployment. The company must advance its nuclear licensing, finalise project financing and establish the manufacturing and construction arrangements required for its first reactors. The proposed PWR-5 pilot at Texas A&M could provide additional engineering and operational evidence, although it would not constitute a demonstration of the PWR-20 itself. The company must also secure electricity purchase commitments sufficient to support project financing. ![Rendering of a Last Energy reactor module](https://storage.ghost.io/c/c3/97/c397e43d-60f4-42e6-acb3-674aa64291df/content/images/2026/10/lastenergy-pwr20-reactor.webp) Image: Last Energy ## Why it matters Last Energy’s proposed 20 MWe units could make nuclear-generated electricity available to customers whose requirements do not justify a conventional large reactor. The economic challenge is whether projects of this size can recover their licensing, construction and operating costs while delivering competitively priced electricity. The company’s first deployment will provide an important test of that proposition. ![Rendering of a Last Energy multi-unit plant next to an industrial site](https://storage.ghost.io/c/c3/97/c397e43d-60f4-42e6-acb3-674aa64291df/content/images/2026/10/lastenergy-multi-unit-array.webp) Image: Last Energy ## Technical note The PWR-20 is designed to produce 20 MW of electricity from 80 MW of thermal energy, implying a thermal-to-electric conversion efficiency of approximately 25%. That is lower than the roughly 33–37% typical of large commercial pressurised water reactors. Smaller steam turbines generally operate less efficiently, illustrating one of the technical trade-offs involved in reducing reactor size. ## Company data | Founded | 2020 | | ------------------------------ | -------------------------------------------------------------------------------------------------------------- | | Headquarters | Washington, DC, United States | | Leadership | Bret Kugelmass, Founder and CEO | | Sector | Nuclear energy / microreactors | | Technology / Product | PWR-20 pressurised water microreactor | | Key Projects | Four-unit PWR-20 project, Bridgend County Borough, Wales; PWR-5 pilot project at Texas A&M-RELLIS. | | Development / Commercial Stage | PWR-20 in development and licensing; no operating reactors | | Ownership / Investors | Privately held; investors include Gigafund | | Funding | $40 million Series B announced in 2024 | | Markets / Customers | United Kingdom, Poland and Romania; proposed long-term electricity supply agreements with commercial customers | | Website | [lastenergy.com](https://www.lastenergy.com/?ref=atomicinsider.com) | ## What to watch - **Wales:** Progress through nuclear site licensing and subsequent regulatory approvals for the proposed four-unit project. - **Texas A&M:** Construction and testing milestones for the PWR-5 pilot, including what the programme demonstrates that is applicable to the PWR-20. - **Commercial commitments:** Conversion of announced customer agreements into financed projects with defined electricity prices and delivery schedules.