London has 99 data centres and 26 more planned; Barnet has one, due to close. The Assembly asks Water UK and campaigners about the cost on 12 November.
Barnet has one data centre and it is due to close, while Brent Cross Town is lining up a new one. On Thursday 12 November at 2pm the London Assembly’s Environment Committee starts asking what London’s data centre boom costs in power, water, noise and clean air, at a public meeting in the Chamber at City Hall.
London has 99 data centres, more than 80 per cent of the UK’s data centre capacity, and around 26 more are planned or going through the planning system, the Assembly says. Members will look at “energy demand, water use, air quality, noise, biodiversity and the impact on local communities”, and at how London can “balance the growth of digital infrastructure with environmental sustainability and local infrastructure capacity”.
Anyone can go. The session can also be watched live or afterwards on the Assembly webcast or the London Assembly YouTube channel.
Where Barnet stands
The count of 26 comes from research Buro Happold carried out for the Greater London Authority. Its borough table, dated November 2025, lists one operational data centre in Barnet and none planned. “Barnet’s only existing data centre is set to be decommissioned,” the report says. “While a relatively small site, it serves as a reminder that not all data centres are retained.” It does not name the site. (Buro Happold for the GLA, London’s Data Centre Future Growth Forecasts and Strategic Insights, December 2025)
Next door, Brent has three operational and two planned, and Enfield three operational. Camden has one, and Haringey and Harrow none. The heaviest clusters are elsewhere: 29 in Tower Hamlets, 15 in Hillingdon and 9 in Ealing.
That picture is already changing here. The Brent Cross Town business plan going to Barnet’s Cabinet on 17 November lists a data centre as the scheme’s fifth phase, with Cabinet approval targeted for February or March, and talks of “clustering of businesses” around it. The report does not say where on the site it would go or how big it would be. (Barnet Live, 8 November)
The Buro Happold study also picks out North London as “an emerging opportunity for growth”, centred on Enfield and the Lee Valley. It says the North London Reinforcement Project, which is upgrading the overhead power line between Pelham and Hackney from 275kV to 400kV by 2028, will boost grid capacity there.
What worries people about data centres
The committee’s background report lists the concerns that have grown in recent years:
- high energy use and the carbon that comes with it, which strains grid capacity
- water for cooling, which “can be in large quantities”, although the report says the data “lacks transparency”
- “urban heat island” effects, warming the land around a site, which matter most in a heatwave
- noise, usually “a low-level hum but can be heard a mile away or more”
- air quality, often from testing back-up generators
It cites residents of the Wesley Estate in Park Royal, where ten data centres already operate and more are proposed, who have raised air quality and noise. The report also points to the upside: waste heat that can warm homes and offices through heat networks, and money for local improvements such as biodiversity.
Who is giving evidence
The first panel, from 2pm to 2.55pm, is community groups and campaigners:
- Oliver Hayes, Head of Campaigns, Global Action Plan
- Olivia Law-Zygadlo, Park Royal resident campaign lead
- Karen Fitzgerald, North Ockendon resident and lead campaigner for “No to East Havering Data Centre”
The second, from 3pm to 4pm, is utilities and academics:
- Charlotte Wood, London Area director, Environment Agency
- Jon Chappell, Deputy Director, Water UK
- Bob Burgoyne, Associate Director, Carbon Trust
- Rory Murphy, Research Associate, University of Exeter
The committee is chaired by Gareth Roberts AM. This is the first meeting of its investigation into data centres.
The rules that would apply in Barnet
The draft London Plan, published for consultation in July, has a data centre policy of its own for the first time, policy GLE3. It tells boroughs to identify suitable locations in their Local Plans, says data centres should favour brownfield land, and says they “should be as clean and sustainable as possible”, with heat recovery, water and electricity efficiency, and renewable power on or near the site where feasible.
The Mayor has said he wants London to be a “global leader in Green Data Centre Innovation”. The government has called data centres critical national infrastructure and plans a national policy statement to guide planning decisions on them.
Getting there
The meeting is in the Chamber at City Hall, Kamal Chunchie Way, E16 1ZE, a short walk from Royal Victoria station on the DLR. The full agenda is on the Assembly website.
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