US tech firm reveals more about its plans to build one of Europe’s largest data centres in green belt land just to the south of Potters Bar

Potters Bar residents have had their first chance to learn more about a proposed data centre which is to be built on an 85-acre suite alongside the M25 motorway.

Itwill be so big it will almost fill the fields between the South Mimms service station at Junction 23 and Dame Alice Owen’s School – see diagram above.

Outline planning permission was approved by Hertsmere Borough Council a year ago for a 2 million square foot development which local objectors claim will be equal to the size of Wembley stadium and will obliterate green belt countryside.

Equinix, a US tech firm which is one of the world’s largest data centre operators, is proposing to invest £3.9 billion in the new centre which will be known as the Hertfordshire Campus, and which will be one of the largest in Europe.

The campus will require 250 megawatts of power – enough to run the equivalent of about 200,000 homes – and to meet the demand, National Grid is to supply the new campus with its own connection to the electricity grid ready for the data centre to come on stream in 2031.

A two-day exhibition of Equinix’s plans was held at Dame Alice Owen’s School where a group of local objectors gathered outside to express opposition to the loss of “incredibly precious countryside” for a development which they say will blight the area.

Ros Naylor (above, second from right), who is one of the lead protesters, said Potters Bar residents had enjoyed walking, riding and cycling along 11 rights of way across the fields between the outskirts of the town and the M25.

“The visual impact alone is going to obliterate local green belt land and instead we are going to have a monster development the size of Wembley stadium.”

She was joined for the protest by (from left to right) Fleur Albrecht, Councillor Simon Rhodes, and Margaret Ohren.

Councillor Rhodes, who serves on Hertfordshire County Council, pointed to the fields which would be lost when the data centre is built.

He had been shocked to discover that the emergency entrance would be via Bridgefoot Lane, directly opposite the entrance to Dame Alice Owen’s School.

“We are only just finding out what Equinix is proposing. We have checked with residents in around 1,500 houses nearby and none of them knew about it. Since January we have as a group registered 950 objections.”

Equinix is proposing to build a campus which would comprise four separate data centre buildings – three would be of 72-megawatt processing capacity and one of 48-megawatt capacity.

Building the campus at South Mimms would represent a £3.9 billion investment in the area, creating 2,500 construction jobs and 200 permanent skilled roles. The campus would generate £18 million a year in business rates.

In presenting an artist’s impression of how the campus would look, Equinix said it intended to retain and improve all the pedestrian, cyclist and bridle ways across the site.

During March there would be an archaeological fields inspection of the site followed an ecological survey in May.

Outline approval for the scheme was granted to a consortium known as DC01UK.

Equinix signed up to proceed with the project and the company’s aim is to submit a detailed planning application in August/September in the hope of starting construction in mid-2027 and the centre going on stream in 2031.