Summary
- City Hall says London has 99 data centre sites using around 760MW at peak demand, with future connection requests around ten times current use.
- The Mayor of London plans a whole-city approach involving boroughs, energy providers, developers, companies, and universities.
- The draft London Plan is expected to introduce data centre policy covering environmental impact, energy demand, heat reuse, and alignment with housing growth.
City Hall is preparing a coordinated approach to data centre development after new analysis found that London’s future grid connection requests are around ten times the power currently used by the capital’s data centres.
The Mayor of London, Sadiq Khan, has said City Hall will convene a roundtable with boroughs, energy providers, companies, developers, and universities. The work follows a City Hall report prepared by Buro Happold, which puts London’s existing data centre base at 99 sites using around 760MW at peak demand.
London remains the UK’s largest data centre hub and one of Europe’s most important digital infrastructure markets. The pressure has shifted from whether demand exists to whether the city can coordinate power, planning, heat reuse, and environmental performance while also supporting housing, transport, and electrification.
A capital-scale power queue
City Hall says existing London data centres use peak electricity equivalent to about 750,000 homes. That is already a material load on the capital’s energy network, but the queue of future connection requests is much larger.
Not every queued project will be built. Some may fall away because of planning risk, financing gaps, customer uncertainty, or national grid connection reform. Even so, a queue roughly ten times current use changes how data centres are treated inside London’s infrastructure planning. They are no longer a niche industrial use class or a borough-by-borough planning question.
The next London Plan is expected to include a new data centre policy, with the draft due this summer. City Hall says the policy will address environmental impacts and take a strategic approach to major energy users, so that data centre growth aligns with housing ambitions rather than competing with them.
National Grid is also investing in the capital’s network. City Hall cites nearly £3bn of planned investment in London over the next five years, alongside more flexible and innovative connection approaches for large sources of demand. That combination of reinforcement and flexibility is likely to shape how new data centre schemes are assessed.
Heat reuse moves into policy
Waste heat is likely to become one of London’s practical tests for new capacity. The Old Oak and Park Royal Development Corporation’s heat network is already being used as an example of how data centre heat could support low-carbon heating for homes and businesses.
Heat reuse is attractive in policy terms because it turns rejected thermal energy into a local resource. The engineering and commercial details are harder. Heat networks need customers, pipes, finance, temperature compatibility, long-term offtake arrangements, and confidence that the data centre will operate consistently enough to justify the infrastructure.
Cooling choices will also carry more scrutiny. A facility using evaporative cooling, dense liquid cooling, backup generation, or large electrical plant has a different local impact profile from a standard warehouse. Planning authorities will increasingly need to understand water use, noise, heat rejection, emissions, grid impact, and resilience as part of one development case.
London’s wider constraint is that data centre growth sits alongside other demands on the same power system. Housing, EV charging, heat pumps, public transport, and commercial electrification all need capacity. A data centre connection can support cloud and AI services, but it can also absorb network headroom that might otherwise support residential or industrial growth.
That tension explains the move towards whole-city coordination. Individual schemes may still proceed through local planning routes, but the capital’s grid queue has become too large to handle as isolated applications. Developers will need stronger evidence on power availability, environmental performance, heat export, and alignment with strategic infrastructure plans.
London has the demand density that makes it attractive to cloud, colocation, network, and AI customers. It also has the land pressure, grid pressure, and political scrutiny that can slow or reshape development. The roundtable and draft London Plan will show how far City Hall is willing to move from encouragement into firm conditions for future data centre growth.
