In the looming shadow of a waste tip, Britain's dream of becoming an AI superpower is playing out.
The low-tech business of dealing with rubbish is meeting the cutting edge of artificial intelligence in the form of a data centre proposed by developer Era4 at a huge landfill site in Kent.
A slight but distinct smell wafting across the countryside from the landfill site provides a clue about how the data centre would be powered.
“We call it The Mountain,” says Ivor Herdson, a 74-year-old retired printer, of his neighbour in the village of Broad Oak.
Methane is not just a legacy issue here but a pathway to future development. The site has been chosen because the gas generated by the region's decomposing rubbish can be used to generate electricity for the data centre, says Era4 in its planning application.
As the UK suffers its third heatwave of the summer, using methane will help cooling – one of the hot button issues of the data centre building boom.
The improbable location is one of over a 100 proposed developments in a rapidly expanding and controversial sector that provides the computing power for the AI revolution.
The large amounts of electricity and water needed for powering and cooling thousands of servers has led to an environmental backlash.
Protest templates pioneered in the US are being used in Britain during the surge in data centre construction, leading developers to find new ways of building.
The proposals in Broad Oak have already led to an online petition that has attracted 3,000 signatures and is growing all the time.
The focus of objections has been on the amount of water the data centre could consume for cooling its processes. Era4 believes it can allay what are genuine concerns. A few weeks ago, residents in Kent had to drink bottled water after supply problems, and the county has been designated an area of “water stress”, despite its bucolic image as the Garden of England.
The petition cites claims from the US that data centres have led to water pollution. It is accompanied by a link to footage of Democratic congresswoman Alexandria Ocasio-Cortez holding up a jar of brown liquid as a prop.
Tech UK
Era4's planning application will be decided by elected local representatives after two councillors said they had “deep concerns” about some issues, including water consumption.
Anxiety about what they allege to be lack of clarity from the Era4 is borne out in the nearby village of Sturry.
“There’s a lot of local concern about this. The information is vague, particularly about the use of water,” said one local resident who asked for her name to be withheld.
A closer look at the specifications of the proposed data centre reveals how it plans to employ technology to operate in an area of water shortages.
According to the planning application, the data centre's design uses a closed-loop liquid cooling system.
This circulates water through sealed pipes to absorb heat from the data modules, transferring the energy to external heat exchangers, while keeping the cooling fluid contained so it can be reused. Unlike systems that evaporate water, the loop avoids water discharge.
The closed loop liquid cooling system also has the advantage of enabling a higher density of processing unit racks.
Tech UK, an industry body, found that 51 per cent of sites use cooling systems that require no water beyond the regular functioning of a building and that 64 per cent use less water annually than a typical leisure centre.
Sophie Greaves, Tech UK’s associate director for digital infrastructure, told The National that the issue of data centres' water consumption was not clear-cut.
“I appreciate that globally water is a scarce resource, but data centres are not as water-intensive an industry as one might be led to believe, especially in the UK,” she said.
“More water is lost in one day through leaks than the entire data centre sector uses in a year.”
Power hungry
The UK has bold ambitions to become an “AI superpower” and the fastest adopter of the technology in the G7.
There has been a surge in AI construction projects with an estimated 450 to 500 data centres in the UK. That number is expected to increase significantly as part of a global trend.
Data centres need a large amount of electricity to power the IT equipment. So rather than size in square metres, a data centre is most commonly defined by its maximum IT load – the incoming power capacity.
Barbour ABI, one of the UK’s leading providers of data on construction projects, has compiled a list of 120 future data centre projects that are either at the planning application stage or under construction. Some of them are not due to be completed until the next decade, in one case 2037.
Using data provided on the planning applications, from the companies and figures reported on specialist websites for 68 of the data centres, it is possible estimate the annual electricity consumption in terawatt-hours (TWh).
This is done by using the sum of all the data centres' capacity, multiplied by a metric called power usage effectiveness (PUE) and the number of hours in a year. It assumes a utilisation of 60 per cent.
The projects identified would consume an estimated 63TWh hours of electricity a year if they all come to fruition. The UK’s current annual power consumption is 322TWh.
The power consumption of data centres can vary between tenants and the workload. Also, data centres are becoming increasingly efficient.
Some of the projects may never be completed but the figure illustrates the scale of ambition among developers.
The proposed projects range in size from the 1GW Elsham Wolds, a 176-acre site that would be the UK’s largest, to a data centre at Alleyn’s School in Dulwich. One terawatt is 1,000 gigawatts, which is 1,000 megawatts in turn.
The owners of Pinewood Studios, where the James Bond, Star Wars and Harry Potter films were made, also want to get in on the act. They have submitted plans to build a £1 billion data centre at the site in Hertfordshire.
The National Energy System Operator (NESO), which operates the UK grid, estimate data centre consumption to be 7.6TWh in 2025. Its own forecasting electricity puts electricity demand anywhere between 30TWh and 71TWh by 2050.
Tom Hegarty, head of communications for environmental campaigners Foxglove, said that “even if only a fraction of these proposals go through, we will still see a huge increase in energy demand, with massive consequences for the rest of the grid – and the households, hospitals and everything else that it powers”.
Slough central
The UK’s existing data centres are clustered in Slough, west London, on the flight path into Heathrow. The town is home to 40 of them, the largest concentration outside the US.
Fibre connectivity, access to a skilled workforce, direct transport links to London, proximity to Heathrow airport, and available sites have all contributed to its popularity.
As Slough heads towards saturation, data centre providers have been looking to next-door Hillingdon, which is now experiencing its own boom in hyperscale data centres.
But that has brought into focus a challenge facing Britain’s data centre developers – access to the grid.
NESO has said there are 140 data centres in the queue for grid access, representing approximately 50GW of capacity. For comparison, this year’s peak electricity demand, which occurred on February 11, was 45GW.
Hillingdon recently approved Colt Data Centre Services’ application to expand its campus, adding 97MW of IT capacity at Hayes Digital Park.
But the drive to build data centres in the borough has rubbed up against the other issue that is fixating Britain – increasing home ownership.
Hillingdon Council told The National that the electricity network serving west London, including its area, reached full capacity in 2022, which temporarily delayed a number of housing developments across the area.
Short-term measures allowed 12,000 homes to be connected by early 2025 which addressed the immediate backlog.
“However, the rapid growth of energy‑intensive data centres in west London continues to place significant pressure on local grid capacity, with some developments previously warned they could face waits until 2037 without further upgrades,” said the council.
Hillingdon is clear it does not want to see data centres come at the expense of new homes for Londoners.
“Looking ahead, long‑term strategic investment in the electricity network – alongside clearer national policy on the siting and planning of data centres – will be essential to ensure that housing delivery is not put at risk again.”
Kevin Restivo, who heads the data centre research team at property company CBRE, said power is in “scarcer supply than ever”.
“Developers tend to run in flocks in that they tend to over congregate in clusters, Slough being the most prominent example in the UK,” he said. “There isn't really any available capacity for years to come in not just Slough, but in west London.”
TechUK said the wait for connection has been up to 15 years but reforms have been introduced that could bring that down to three to six years.
Britain’s high cost of energy is also an impediment to growth.
For a 500 megawatt data centre, the annual electricity bill is about £900 million ($1.2 million), compared to £700 million in France ($936 million) or £200 million ($267 million) in Spain, says TechUK’s Sophie Greaves.
Small is beautiful
As data centre projects spring up across Britain, others are putting forward an alternative model to meet the demands of AI.
Many believe that the future lies in edge data centres. These are located close to the edge of a network, closer to end users and devices.
Amanda Brock, who heads OpenUK, an organisation which promotes open source technology, believes Britain should adopt a more appropriate data centre model.
The “monolithic data centres that we're seeing being built in the US” are being built for AI training but the UK is not in the same position due to the copyright law.
Ms Brock said as “you move from training to inference” where the trained model applies learnt knowledge “you need smaller data centres”.
“My view is that the small data centre is going to be the future of AI. If you look at any high street you will see empty shops everywhere in the UK,” she said.
“Some of that could be converted from being eyesores into nice-looking small premises … to be used as local data centres next to the end user.”
The idea is already being put into practice through the unlikely marriage of data centres and swimming pools.
Deep Green, a British start-up, began capturing heat from its data centre servers and transferring it to Exmouth swimming pool’s hot water system, for free in 2023.
It is now doing the same for a swimming pool by its facility in Urmston, near Manchester, and has secured planning permission for another site in Bradford.
“Data centres are often viewed as essential but extractive, consuming large amounts of power while offering relatively few local benefits. That need not be the model,” said chief executive Mark Lee.
“Britain will need far more AI infrastructure as AI becomes embedded across the economy, and the communities that host it should share in its value.”
Peter Gilpin, chief executive of pool operator LED, said the partnership with Deep Green began just before the war in Ukraine, which saw the cost of gas triple.
“So this has been very timely in that with the cost of gas and electricity rocketing up, the savings are greater,” he said.
Boris Gamazaychikov, the co-founder and chief executive of Sustainable AI, said the need for block-sized data centres could be questionable and the future might lie instead in the palms of our hands.
“You can actually run a model that's the quality of [Chat] GPT-4, which was state of the art two years ago, on your phone today.”
