The energy vampires sucking Britain’s grid dry

·5-min read
The energy vampires sucking Britain's grid dry - Ruby Martin for The Telegraph
The energy vampires sucking Britain's grid dry - Ruby Martin for The Telegraph

A shortage of houses in London and the south east has long been one of the most prolific problems facing the Government.

Yet desperately needed fresh supply is unlikely to materialise soon in west London, after developers were last week told they may be prevented from starting new projects in the area until 2035, because the electricity grid has run out of capacity.

But it isn’t just tightening energy supplies amid the war in Ukraine that is behind the de facto ban - surging demand for data centres is sucking Britain’s power grid dry.

These warehouse-sized buildings full of computer servers absorb so much electricity that the Greater London Authority (GLA) told housebuilders it may be more than a decade until new developments in Hillingdon, Ealing and Hounslow can be sustained by the grid.

Much of the problem boils down to the economic success of the M4’s “Silicon Corridor”. As technology and finance companies compete for office space near the data centres that power their businesses, demand inevitably begets greater supply.

Roughly half of Britain’s estimated 200 data centres are in the south east of England, with a large proportion concentrated in the area between Reading and Ealing.

SSE, the electricity distribution network operator covering west London and Slough, estimates a typical data centre campus needs 50 mega volt ampere (MvA), which is the electrical demand required by developments of 5,000 to 10,000 homes.

With around a dozen planning applications for new data centres outstanding across the area, the huge power demands of these data centres bear closer scrutiny.

In Ealing, for instance, there are currently seven applications to build new data centres sitting in front of planning inspectors.

A memo sent to housebuilders by the GLA this month, seen by The Telegraph, said data centre planning applications were blocking new housing developments until 2035.

It said: “Over the last two years the Distribution Network Operator, SSEN, has experienced the same volume of new data centre connection requests in west London as the total electricity demand of the area.”

Parts of the south east may not get any new homes until 2035
Parts of the south east may not get any new homes until 2035

Jump in remote working

According to sources, authorities have broadly been operating a first come, first served system for allocating electrical demand. But a jump in remote working since the pandemic has helped to push up demand for data processing and connectivity - and the electricity to serve it - meaning the current system is no longer fit for purpose.

A spokesman for the Energy Networks Association described west London’s problems as an “isolated circumstance caused by a quick and concentrated expansion of demand from a localised growth in data centres, far higher than forecast.”

Yet the power supply problems are not confined to the three boroughs highlighted by the GLA. They extend further west into the Thames Valley, stretching as far as Reading.

Tech companies such as Oracle, Microsoft, Dell and Huawei all have bases here, due in part to nearby transatlantic data cables feeding London. These broadly follow the M4, and businesses along their route are keen to tap into these conduits of commerce - soaking up the grid’s power.

Estimates from the International Energy Agency (IEA) say data centres account for around 1pc of global electricity consumption, at between 200-250 terawatt-hours, with demand rising “exponentially”.

Inextricably linked to data centre power usage is power consumed by data transmission networks, the fibre-optic nerves and arteries of today’s digital economy. While the IEA says energy intensity from these networks has halved every two years since the millennium, they still account for up to 1.4pc of global electricity demand.

It means that in areas such as west London, data centres drink electricity - and their insatiable thirst is creating a drought in the surrounding area.

One six-foot high rack in a data centre holds up to 42 servers, and consumes about six to eight kilowatts (kW) of electricity. A typical data centre might hold a few thousand racks, meaning an industrial estate-sized building can contain between 500,000 and 1 million servers depending on internal layout.

Reading data centre
Reading data centre

Powering down energy needs

Powering the servers is only part of the data centre electrical equation. Intensive calculations required for artificial intelligence (AI) or enterprise IT work generate heat.

Cooling fans need to be installed to take that heat away, and with such large numbers of servers in such a small space, data centres need large and powerful industrial air conditioning systems to prevent a literal meltdown from occurring. About 40pc of a typical data centre’s power consumption is used on running the air conditioning.

With those figures in mind, it is easy to appreciate how data centres such as data centre operator Virtus’ London-2 facility in Hayes, Hillingdon, needs to draw up to 12.2 megawatts (MW) from the National Grid.

Slough, on the border of Hounslow and Hillingdon, is home to half a dozen such public data centres, as well as a number of single-user sites operated by big tech companies. Nearby Heathrow Airport has at least two public data centres and a significant number of private ones nearby, serving airlines and the travel industry. British Airways has two data centres near Heathrow, powering the airline’s operations and providing backups in case of failures.

Moves are afoot to reduce the power requirements of data centres.

Craig Melson, industry body TechUK’s associate director for sustainability, said industry was working on initiatives such as the Open Compute Project, a Facebook-led scheme to redesign servers so they use less energy.

Meanwhile, Business Secretary Kwasi Kwarteng has promised a partial solution by next year, saying energy regulator Ofgem “has decided to change the connection charging framework, from April 2023, which would see connection costs fall for housing developers requiring [electricity] network reinforcement to accommodate their connections.”

Ultimately, the answer lies with electricity generation and distribution capacity, combined with political pragmatism that lets smaller new housing developments leapfrog data centre build and fit-out cycles.

While data centres may be vital to modern business and technology-reliant lifestyles, their vast electrical demands add yet another hurdle to solving Britain’s housing crisis.