Fierce competition between would-be data centre developers has played havoc with Britain's queue of projects seeking access to the electricity grid.
With at least 80GW of data centre projects in the connection pipeline, the Labour government moved earlier this year to consult on proposals to curtail speculators snapping up spots in the connection queue.
But buried in the consultation document is also a proposal for embedding "demand flexibility" into data centre grid connection agreements.
Residents
If adopted, this could send Britain down the same road as the US, where regional grid operators are now regularly asking data centre operators to use back-up power to relieve strain on the electricity system.
As temperatures climbed to record levels across the Eastern states of the US in July this year, residents living near massive data centre clusters saw black smoke billowing from the facilities' banks of diesel back-up generators.
Two punishing heatwaves that month prompted PJM Interconnection (PJM), the electricity grid operator serving 14 states across the region, to ask "large load" customers, including data centres, to switch over from the grid to their own power sources in order to avoid blackouts.
According to data released by PJM for 3 to 5 July and 14 to 17 July, the operator relied on generators running for 1,799 hours beyond the limits set down in their environmental permits, providing 9 GW of relief for the overloaded grid.
Environmental campaigners representing residents living in areas dominated by the region's data centre clusters slammed the decision, which was authorised by the US Secretary of State for Energy.
Pioneered
"Diesel generators turning on!", The Coalition to Protect Prince William County, a community environmental organisation in Virginia, warned in an alert sent out to supporters on 1 July.
The campaign group added: "The audacity to suggest that turning on DIESEL GENERATORS saves lives because DATA CENTERS take too much power is ludicrous.
"We have said this before, and we will say it again: being grateful that data centers remove their load from the grid and rely on dirty diesel generators that pollute our air, is like thanking the arsonist for bringing you a bucket of water after they set your house on fire."
Virginia’s data centre cluster is the largest in the world and local energy companies have long struggled to cope with the challenges of intense competition for power and connections.
The state which pioneered the data centre boom even recently agreed to levy a special tax to pay for electricity infrastructure and reduce pressure on household bills.
Power
But will the pattern of increased reliance on dirty diesel back-up generators and other on-site fossil fuel power sources spread elsewhere?
Energy research institutes and international organisations say that data centre clusters present problems which will challenge all electricity grid operators, intensifying as AI production and usage accelerate.
“Emerging, computation-intensive capabilities such as image, audio, and video generation have no precedent,” a 2024 report from US energy research organisation EPRI warned.
The report highlighted the growth of exceptionally large “point loads” – geographically concentrated, large-scale demand for electricity – as a key risk for grid managers and other local users.
And with long queues to connect the grid, data centre operators are increasingly turning to a "bring-your-own-power" model using onsite gas power plants, according to the International Energy Agency.
Scarce
Britain's data centre clusters are still much smaller than those in the US where the digital infrastructure boom started earlier. But energy systems experts say that there are lessons from PJM's problems which apply to the rapidly expanding data centre sector here.
James Sumnall, an energy analyst at Energy Systems Catapult, told The Ecologist:“So-called ‘clustering’ matters in the UK too because data centres tend to concentrate where there is suitable land and strong fibre and grid connectivity. That can compete with other local infrastructure priorities and can lead to local opposition."
He added: "The main pressures are often local, because it matters where demand is situated and how quickly it is growing.
"London and parts of the South East already have limited spare capacity in the energy network, and that is where rapid growth can create operational stress and difficult trade-offs.”
Competition over scarce water supplies during heatwaves also creates a different kind of trade-off dilemma in regions with large data centre clusters.
Drought-stricken
Spikes in data centre water and power demand can't be easily separated, and they tend to occur in sync with heatwaves.
Running expensive servers and IT equipment in the heat increases the chances of breakdowns so just as overheated homes, hospitals and offices switch on their fans and air conditioning systems, data centre operators are likely to be doing the same.
The issue of keeping temperatures artificially low is more acute for data centres running AI workloads because these require far more energy than other types of computation.
Public criticism of data centre water consumption has prompted some large operators to adopt so-called "waterless" systems for cooling which use less water on-site compared to evaporative cooling systems, but use far more water at the power source.
Heatwaves across Europe this summer have seen falling water levels in drought-stricken rivers forcing power-stations which rely on river water for cooling to shut down.
Divert
Britain's electricity grid relies regularly on its interconnection with France to help balance supply and demand, but with one-fifth of French nuclear power stations off-line in August due to drought conditions, the challenges for operator NESO are multiplying.
Even before the recent heatwaves, NESO issued emergency measures to preserve the UK's electricity supplies, triggering a political row and accusations from a Tory shadow minister of a "cover-up" over the risk of blackouts.
Proposals for integrating the UK's data centre back-up generators into "demand flexibility" schemes will be debated in this heated political atmosphere.
Meanwhile, the scramble to build new data centres poses risks to expanding renewable power generation, according to a key energy industry body.
Energy UK warned that the speed of data centre expansion risked creating "sudden and intense pressure on the electricity system."
The government's plans to prioritise data centre access to network capacity "could divert resources away from the essential reinforcement needed to connect renewable generation projects," the statement added.
This Author
Anne Alexander is a journalist and researcher. She is working currently working on a project with Watershed Investigations looking at the impact of data centres and the AI industry on the living planet.