Anne Alexander, researcher and freelance journalist explains what the US, Ireland and Slough tell us about the impact of data centre clusters on our electricity system and the size of the speculative boom in Scotland. Slough, the data centre capital of Europe, two decades in the making, has a capacity of 413MW, two thirds that of just one data centre in Scotland, the Auchtertool proposal, and less than half that proposed at Chapelcross.
This was published in The Herald What the US, Ireland and Slough tell us about the impact of data centre clusters on our electricity system
Across the world data centre construction is booming, despite worries about the power-hunger of this expanding industry. So what does the experience of towns and cities in the US, Ireland and England already hosting large data centre clusters tell us about the potential impact of similar projects on Scotland’s electricity grid? And why are some of the places which welcomed the industry for decades now implementing policies to make operators pay more for electricity or facing a community backlash?
US electrical industry research institute EPRI highlights that surging electricity demand is a common feature of data centre cluster growth. EPRI’s 2026 Powering Intelligence report estimates that by 2030 data centres will consume between 9 and 17 percent of total US electricity demand, up from 4-5 percent today. The national averages conceal intense hotspots of demand in locations such as Virginia, the state which launched the data centre explosion. The share of electricity demand taken up by data centres there is currently around 20 percent, but EPRI estimates that could double by 2030.
Virginia’s “Data Center Alley” is located around the town of Ashburn. According to global estate agent CBRE the area’s 4496 MW of data centre capacity makes it the largest market in the US. Tech companies have poured billions of dollars into Northern Virginia’s digital infrastructure for decades. But now calls from environmental groups for a moratorium on data centre construction are being echoed across the political spectrum. Republican Glen Sturtevant sits in Virginia’s senate. He’s campaigning a pause on data centre approvals. “I don’t want my area to become the next Data Center Alley”, he told a local radio station.
In Texas, Governor Greg Abbott recently announced a moratorium on data centers grid connections, demanding developers provide full information about local tax breaks, power use and generation, water use and cooling, plans to reduce the impact on local communities and company ownership. Grid operator ERCOT said that it has 1800 projects in its interconnection queue, representing 474,000 MW of electricity, or five times the record peak demand.
The state of Oregon on the US West Coast also has a long history of working with data centre operators. Google, Amazon and Meta started building their own hyperscale campuses around twenty years ago. A data centre hotspot later emerged in the city of Portland attracted by fast internet connections through the submarine data cables traversing the Pacific Ocean to Australia, New Zealand, Japan, China, and South Korea. Big data centre operators clustered around the Hillsboro area, benefiting from Oregon’s zero sales taxes and cheap electricity. One of those companies was CoreWeave, the new long-term tenant in Scottish company’s DataVita’s expanding Lanarkshire campus.
The rise of this new electricity-hungry industry is stoking public debate across Oregon over whether data centre investments benefit local communities. And the share of Oregon’s electricity consumed by data centres compared to the industry’s contribution to paying for grid infrastructure has been a key question. The sector is on track to track to use over 20 percent of Oregon’s electricity by 2030, according to EPRI. Earlier this year, Oregon became the first state in the US to bring in regulations designed to ensure data centre operators pay a larger share of the costs of upgrading and expanding the electricity grid. Under the POWER Act, they are now classified separately from other users, making it easier to compare their demand to other consumer groups such as households. This could trigger a nearly 30 percent rise in the cost of electricity for data centre operators.
Joshua Basofin, Energy Program Director at Climate Solutions, an Oregon non-profit which campaigned for the POWER Act said that data centres were “largely unregulated” during the first twenty years of their growth in the state. “There is very little transparency around contracts to site data centres, tax abatement deals, and the resources (water, energy) data centres use. This has created a ‘black box’ situation leaving the public and policymakers with very little information.”
Charlotte Shuff from consumer advocacy group Citizens Utility Board also campaigned for the POWER Act. “Our old system of dividing costs between customers ended up putting too much on households and small businesses, despite these groups not seeing the benefits of the investments made for data centres,” she said.
US-based cloud computing companies, including the Big Tech giants Microsoft, Amazon and Google arrived in Ireland in the 2000s. As in the US, an intense clustering effect soon took hold, leading to a concentration of data centres in the Dublin area. According to Ireland’s Central Statistics Office, consumption by data centres rose from 5 percent of all metered electricity in Ireland in 2015, to 11 percent in 2020, to 23 percent in 2025.
Ireland’s data centre expansion has taken place alongside a dramatic growth in clean energy, with the share of electricity generated from renewables rising from under 10 percent in 2006 to nearly 40 percent by 2024. But as data centre clusters took off, a significant mismatch between demand from the sector and the growth of generation capacity developed. Research by the Irish parliament in 2025 noted that the rise in data centre electricity demand was “outpacing new renewable electricity sources”.
Declan Owens from EcoJustice Ireland is an environmental lawyer who has represented Irish community campaigns challenging large data centre projects. “Instead of helping to green the public supply, these clean energy sources are ringfenced for Big Tech,” he said. Irish environmental and community campaigns are now arguing that “because renewables are being diverted, Ireland is forced to keep fossil-gas plants running longer to meet the rest of the public’s needs,” he added.
For over two decades, the Berkshire town of Slough has welcomed data centre operators to the Slough Trading Estate (STE). Property developer SEGRO set up this massive industrial zone in the 1920s and signed the first lease for a data centre operator in 2005. The location is close to London’s financial centres and big urban consumer markets. It boasts a mass of internet exchanges which facilitate speedy connections to other data centre clusters in the London region. The dense mesh of fibre cables under the town lets data centre operators provide customers with access to an “availability zone.” In the event of equipment malfunctions or power interruptions, workloads shift seamlessly to other data centres nearby, with minimal time delay.
Slough Council’s simplified planning zone covering the STE means that data centre operators don’t have to submit individual planning applications, as long as certain criteria have been met. SEGRO says this provides “significant competitive advantage” for the STE and is a key reason for Slough’s emergence as the UK’s largest data centre cluster.
According to figures from data centre industry analysts DC Byte, the data centre capacity across the Slough Availability Zone grew rapidly between 2020 and October 2025, rising from 177 MW to 416 MW. Bringing large numbers of data centre operators into one location benefits the local economy, argues Jo Jackson, SEGRO’s Western Corridor Director, as it creates “a self-reinforcing cycle where more operators attract more customers, which attracts more investment, which attracts more operators and skilled workers.”
Microsoft’s announcement it is planning to build a massive new data centre in Langley has spurred a growing group of residents into speaking out against expanding the data centre cluster. The location for Microsoft’s new campus is outside the STE, but close enough to benefit from fast connections to the heart of the Slough Availability Zone. Langley resident Dr Ambily Banarjee is one of the organisers of a new Slough Against Data Centres campaign. She said “people are really concerned that the building of data centres could affect their families, their futures, as well as the environment.”
Recently released government figures show that Slough’s electricity consumption is now dominated by data centres. In 2024, they consumed 65 percent of electricity across the entire local authority. Dr Banarjee said this statistic was “shocking”, adding “we know there are reports across the country where lack of grid capacity delays housing developments. Are we going to be impacted in terms of numbers of houses that can be built for the community in residential areas?”
What does this mean for Scotland? The government-backed AI Growth Zone in Lanarkshire will eventually provide 500 MW of “AI-ready” compute, says operator DataVita. That is round the same scale as the entire Slough data centre cluster had reached by October last year. It would also mark a huge jump in size for Scotland. The servers in DataVita’s largest data centre currently operational consume up to 40 MW of electricity, according to the company’s website, around 10 times the capacity offered by all other commercial data centres in Scotland combined. There are also multiple other campuses in Scotland’s planning system around the 500 MW mark including ILI Group’s Cato, Aurelius and Rufus data centre projects spanning a line from Fife to Ayrshire, and Apatura’s proposed Ravenscraig campus.
Kat Jones from countryside charity Action to Protect Rural Scotland says that the Scottish government must not rush headlong into building data centre clusters. “We have been sounding the alarm on the vast energy demands of the proposed hyperscale data centres in Scotland, and the impacts they would have on the grid and energy prices, since last year and the silence from government has been deafening,” she said.
Anne Alexander