Last Energy to Repurpose Welsh Coal Plant Site with 80-MW Micro-Nuclear Fleet

Micro-modular nuclear plant developer Last Energy has unveiled plans to deploy four 20-MWe pressurized water reactor (PWR) power plants at the site of a former coal-fired power plant in South Wales.

Last Energy’s project will transform the Llynfi Power Station, a now vacant site that housed four 30-MW coal units from 1951 to 1977,  the company said on Oct. 15. Pending the licensing and planning process, the company aims to deliver its first plant by 2027.  

The overall capital investment for the project, estimated at £300 million ($393 million), to include equipment, services, and other development activities, is expected to be fully privately funded and will not require public funding. Last Energy plans to source at least 10% of the project’s materials and services from local suppliers, generating a £30 million economic impact in South Wales.

The project is subject to a regulatory review to ensure the design meets rigorous safety, security, and environmental standards. It will be evaluated by the UK Office for Nuclear Regulation (ONR), National Resources Wales (NRW), Planning and Environment Decisions Wales (PEDW), and Environmental Agency (EA). “Last Energy has been actively engaging with ONR, NRW, PEDW, EA, and with local and national Welsh and UK officials, and will continue to do so throughout the project,” it said. It has also kicked off public engagement.

Last Energy Has Cultivated 80 Commercial Agreements

The project marks another lucrative opportunity for Last Energy, which has notched a stunning 80 commercial agreements for its PWR-20 design since its founding in 2020 (up from 34 last year and 50 at the start of 2024). The company launched as a spin-out of the Energy Impact Center, which is a Washington D.C. research institute focused on near-term climate solutions. Its pipeline includes projects bolstered by power purchase agreements (PPAs), all focused on Europe, with most slated for development throughout the UK.

The company’s PWR-20 is a 20-MWe (80-MWth) single-loop pressurized water reactor (PWR) that has a 300C continuous output. The design uses standard full-length PWR fuel enriched to 4.95% and closed-cycle air cooling. A PWR-20 plant is designed for “plug-and-play” deployment, comprising “a few dozen modules that are assembled like a LEGO kit and requires minimal land,” the company notes. “The PWR-20 is designed to be fabricated, transported, and assembled within 24 months and is sized to serve private industrial customers.” Construction timelines are advertised between six and 24 months. 

Last Energy has already built and demonstrated multiple prototypes of the micro-modular power plant design with three different vendors. Qualifying specific vendors and building internal processes for the standardized design has been a crucial aspect of its strategy toward rapid commercialization, it notes.

But, as POWER has reported, the technology’s competitiveness thrives on an innovative “energy-as-a-service” model for the standardized PWR design. “As a full-service developer, Last Energy owns and operates its plug-and-play power plant on the customer’s site, bypassing the decade-long development timelines of electric transmission grid upgrade requirements,” Last Energy explained. “The company intentionally relies on existing supply chains and uses the same reactor technology found in over 300 plants worldwide.” 

The company has said the model “promotes scalability and rapid deployment through multiple, small-scale facilities that rely on repeatable frameworks and off-the-shelf components, allowing nuclear to follow the best practices of the renewables industry: scaling of quantity rather than size.”

“Last Energy differentiates itself within the nuclear sector by focusing all technological innovation on high throughput manufacturability rather than the industry’s historical focus on novel reactor core physics,” it says. Overall, the company is spearheading ambitious goals, seeking to build 10,000 units in the next 15 years.

While originally developed for traditional industrial sectors, like manufacturing, metals, and mining in European markets, the company’s opportunities have proliferated amid massive demand from the data center industry. Its core market, for now, remains focused on serving heavy industry in the UK and data centers and other industrial users in Poland and Romania.

“New nuclear is an integral part of a future power system— providing secure, reliable and always available electricity to consumers,” said Tom Greatrex, chief executive of the Nuclear Industry Association, on Tuesday. “Increasingly, industries are looking to nuclear to provide that reliable and price-predictable heat and power as they seek to decarbonize. Potential projects such as that proposed by Last Energy, with an innovative business model of direct-to-industry power and co-location, will be required if deep decarbonization is to become a reality rather than a slogan.”  

A New Nuclear Prospect for Wales

The Llynfi Clean Energy Project is perhaps as important, given that it marks more progress for nuclear development in Wales, a region with a longstanding nuclear history. Along with the two Magnox reactors at Wylfa, Wales hosted two Magnox reactors at Trawsfynydd, which ran between 1965 and 1991.

The UK government in May 2024, notably, picked Wylfa in Anglesey, North Wales, as its preferred site for the country’s third large-scale nuclear power plant after Hinkley C in Somerset and Sizewell C in Suffolk—a crucial project that bolsters the UK’s ambition to expand its current 6 GW nuclear capacity to 24 GW by 2050.

Great British Nuclear (GBN), the government’s March 2023-launched designated body to fast-track nuclear development, in March 2024 bought land for the Wylfa project from Japanese firm Hitachi at both Wylfa in Ynys Môn/Anglesey and Oldbury-on-Severn in Gloucestershire. GBN has noted that access to nuclear sites “is a critical factor in achieving [the UK’s] nuclear ambitions, which included deploying small modular reactors (SMRs) and exploring a further large-scale reactor project after Hinkley Point C and Sizewell C.”

On Tuesday, GBN noted that Last Energy’s announcement “shows the wide range of opportunities for nuclear energy to power the UK’s growth.” New nuclear remains a “vital part of Britain’s energy future,” it confirmed.

“As well as large-scale power stations like Hinkley Point C and Sizewell C, and the Small Modular Reactors Great British Nuclear is in the process of selecting, these kinds of even smaller reactors can supply heat and power to industries of the future. They are set to drive development and innovation and significantly reduce industrial carbon emissions, which will be of huge benefit to the UK’s economy and will play a significant part in our clean air future.”

—Sonal Patel is a POWER senior editor (@sonalcpatel, @POWERmagazine).