Plans have been filed for a large-scale data center campus next to a former nuclear plant in Scotland.

CX Tech this week announced it has formally submitted plans for a £16.5 billion ($21.77bn), 1GW data center and technology campus at Chapelcross, near Annan in the South of Scotland.

The company has lodged an application for Planning Permission in Principle (PPiP) to Dumfries & Galloway Council for the CX Technology Campus, seeking to develop eight buildings totaling 162,000 sqm (1.74m sq ft) and an on-site substation.

If planning permission is secured this year, construction could run from 2027 to 2035, according to a dedicated project website.

Set to be built out over eight years, the 55-hectare campus will utilize closed-loop, non-evaporative air cooling to reduce water use and use green fuel rather than conventional diesel for backup generation.

CX Tech is exploring direct and private-wire connections to wind, solar, and biomass generation, and claims the site will run “exclusively” on renewable energy. The company has said it is exploring potential waste heat reuse opportunities.

Graeme Anderson, chief executive of CX Tech Limited, said: “Global demand for AI and high-performance computing is accelerating rapidly, but delivering the next generation of digital infrastructure is about much more than simply building additional data center capacity. The challenge is bringing together scale, power, sustainability, resilience and the ability to grow over the long term.”

Used as an RAF and munitions base during WWII (RAF Annan), the site was later home to the Chapelcross nuclear power station. Launched in 1959 and decommissioned in 2004, the nuclear plant totaled 240MW of capacity. Removal and remediation work of buildings is ongoing. The data center campus is proposed on land north of where the nuclear plant was.

CX Tech Limited (previously CX Power) has been appointed strategic development partner for the site by NDA Properties Limited, a wholly owned subsidiary of the UK’s Nuclear Decommissioning Authority.

Anderson founded project management services firm GA Consultants in 2022. Launched late last year, CX Tech held community meetings to discuss its plans in June.

NDA group had previously announced in 2024 that it was working with CX Power to develop a green energy hub at Chapelcross, with the potential to develop AI data centers as part of the project.

CX Tech said the site benefits from an adjacent 132kV Grid Supply Point and is surrounded by “substantial existing and potential renewable energy,” making it suitable for data center development.

Anderson added: “Chapelcross gives us the opportunity to create that platform. We are proposing approximately 1GW of potential capacity on a major brownfield energy site, delivered in phases and designed from the outset around renewable power, highly efficient operation and exceptionally low water consumption. We are not designing this around a single operator or a single point in the market cycle. Our ambition is to create an infrastructure platform capable of evolving with the requirements of AI, cloud and high-performance computing, giving major operators the opportunity to deploy and expand at significant scale.”

South Scotland MSP Laura Moodie, of the Scottish Greens, called for the bid to be rejected.

She told the Holyrood: “The site at Chapelcross should be the best place to put a data center by utilizing a decommissioned brownfield site. But the proposal which has been lodged is reckless and endangers our energy supply and natural environment.”

Say No to Chapelcross AI Data Centre, a Facebook group against the project, has just under 700 members at the time of writing.

Despite ample renewable power, Scotland has traditionally had a very small data center market. In recent years, however, gigawatts of new data center capacity have been proposed across more than a dozen projects.

The rapid growth has seen pushback from local residents, opposition groups, and officials, particularly the Scottish Green Party.

The Scottish Parliament recently backed a de facto but temporary moratorium on hyperscale data centers, vowing not to approve any new schemes until new planning guidelines are finalized, after the Greens put forward a motion.