A proposed data centre development in Cardiff would be accompanied by a temporary gas-fired power plant operating for up to five years, according to plans submitted by developer Curtis Hall. The facility, planned for the site of Cardiff East Park and Ride near Llanrumney, has triggered objections from environmental groups, local politicians, and residents concerned about emissions and noise. According to BBC News, the Welsh government has issued a holding direction preventing Cardiff Council from granting permission while ministers consider whether to take over the planning process entirely.
Curtis Hall stated the gas turbine installation represents a "worst-case scenario" and would only be necessary if the site cannot secure a connection to the national grid quickly enough. The developer has emphasised that the project would deliver significant economic and infrastructure benefits to the area, including a new bridge and link road for pedestrians and cyclists.
The proposal covers approximately 40 acres and would include three data centres, an on-site substation, and ancillary energy facilities, according to Data Center Dynamics. Curtis Hall received permission in June 2024 to demolish and redevelop parts of the site.
What would the temporary power plant involve?
Planning documents detail a "temporary ancillary energy centre" designed to operate from July 2028 until approximately July 2033, when the site is expected to achieve full electricity connection from the national grid. The facility would contain five gas turbines, a steam generator, and two additional gas turbines held on standby, with a maximum generating capacity of 49.9 megawatts.
Curtis Hall denied that limiting the plant to 49.9MW was an attempt to avoid requiring planning permission from the Welsh government, which is mandatory for energy generation facilities of 50MW or above. The company stated that the technology for the energy centre has "not been confirmed" and suggested fuel cells converting gas or hydrogen to electricity could potentially be used instead of gas turbines.
In the long term, the data centre would require a 150MW connection from the national grid, a capacity that may not be available until between 2030 and 2034. An additional 40 diesel backup generators would be installed after grid connection to ensure continuous power supply.
A revised air-quality assessment completed in April 2026 considered newer, lower-emission backup generators and modeled effects at nearby homes, schools, and care homes, according to Nation.Cymru. The developer stated the assessment found the scheme acceptable for public health, and that air quality effects of gas and diesel generators would not be significant.
Why are residents and campaigners opposed?
Residents living in a nearby new-build housing estate have raised concerns about noise, pollution, and environmental impact. James George, 32, expressed worry about diesel generators that would run in case of power disruptions, stating:
"The main concern is the noise and the pollution, like they have to run a diesel generator in case of any power disruption."
Alexander Grant, 51, voiced concerns about the impact on staff and patients at the University Hospital of Wales, which the park and ride currently serves.
"My main worry is the situation with the Heath hospital with regards to the staff and the patients. There's also other reasons as well, from the environmental side of things. I think it's an absolute travesty."
Dale Harvey raised concerns that the development would compound existing noise from the A48 dual carriageway.
"You buy a new build, and we're being told all of a sudden there's going to be generators run - all the fumes and all the noises."
The developer responded that the site would not be audible locally and that air quality would not experience significant impact.
What is the environmental campaign group saying?
Friends of the Earth Cymru has characterised the proposal as "climate-wrecking" infrastructure. The organisation's interim director Jenny Lloyd stated:
"After a summer of heat waves and drought and worries about flooding over the autumn and winter, it's completely irresponsible to give the green light to this climate-wrecking piece of infrastructure."
The use of fossil fuels to power the temporary energy centre has drawn particular criticism from environmental advocates concerned about Wales's climate commitments. In response to these concerns, Curtis Hall pointed to plans for the south Wales electricity grid to decarbonise rapidly through floating offshore wind development.
Which politicians have objected?
Almost all Members of the Senedd representing the Cardiff East area have formally objected to the plans. These include Plaid Cymru MSs Nick Carter, Zaynub Akbar, and Constitution Minister Dafydd Trystan Davies, as well as Labour MSs Shavanah Taj and Paul Rock, a Green MS. Labour MP Alex Barros-Curtis and Reform's Cai Parry-Jones have also raised concerns.
Plaid Cymru MS Nick Carter stated:
"There is no reason why a data centre needs to be sited in an urban area close to schools and care homes, when in fact underneath the headlines is a small gas-fired power station."
Nick Carter and Zaynub Akbar have requested that the Welsh government call in the application, arguing the issue "should be a question of national policy, not determined piecemeal" by individual local councils "without guidance." Local Cardiff Liberal Democrats have made similar requests.
Senior Labour councillor Lee Bridgeman, a member of the Cardiff Council cabinet and Llanrumney ward councillor, added his objection this week. In a letter, he stated it was "hard to reconcile" the centre's emissions "with Cardiff's climate emergency declaration and Planning Policy Wales."
What is the developer's response to criticism?
Curtis Hall has emphasised that the gas generation would not be the data centre's permanent power supply. The company stated:
"If the connection arrives in time, the energy centre will not be needed at all. Gas turbines appear in the planning documents because they represent the worst case for emissions and noise, so assessing them tests the upper limit of any impact."
The developer noted that the project would bring "significant benefits," including "the delivery of the new road bridge" and by helping "attract much-needed investment, create well-paid jobs and provide new training opportunities."
Curtis Hall previously held planning permission for a logistics centre on the site but switched to proposing a data centre due to "changing market demand," according to Cardiff Council.
What happens with the park and ride?
Cardiff East Park and Ride currently serves staff and patients using Cardiff's University Hospital of Wales, Wales's largest hospital. The Cardiff and Vale University Health Board has described the facility as an essential transport link and stated it was committed to finding a suitable alternative location.
Cardiff Council has said it is seeking an alternative site for the park and ride. A council consultation on relocation options is running until 28 October.
What is the current status of the planning application?
The Welsh government has issued a holding direction, preventing Cardiff Council from granting permission while ministers decide whether to call in the application and make the final decision themselves. A spokesperson for Cardiff Council said the planning application was still being considered and would be reported to a formal planning meeting in future. The council noted that the holding direction was "not unusual, given the significant level of public interest in the application."
No decision date has been reported for when ministers will conclude their consideration of whether to call in the application.
What is the Welsh government's broader policy position?
The Welsh government is separately developing its own "sustainable development policy" on data centres generally. Planning Minister Siân Gwenllian promised at the Plaid Cymru conference in Llandudno in October that the policy would be published before the end of the year.
At the conference, Gwenllian told party members:
"These data centres are needed to sustain a modern economy."However, she emphasised that while data centres must benefit the economy, the facilities "must be on our terms."
Why are data centres becoming controversial?
Interest in building data centres has increased significantly with the rise of artificial intelligence technologies. However, these facilities have become controversial worldwide, primarily because of the substantial amounts of electricity they require. The Cardiff proposal reflects broader global debates about where data centres should be located and what environmental safeguards should apply to their development.
