How Slough Became a Global Data Centre Powerhouse
Slough has, for many years, had a reputation among Brits as an unremarkable place. Today, however, the Berkshire town is known for something very different: having one of the world's largest concentrations of data centres.
Home to around 40 large-scale facilities, the cluster includes facilities operated by Equinix and Digital Realty, while cloud giants including Amazon, Google, Oracle and Microsoft all rely on infrastructure in the town.
Industry estimates suggest the campus now has a combined IT load of around 1GW: enough electricity to power hundreds of thousands of homes.
Yet as the UK's recent heatwave pushed temperatures to record levels, researchers and residents alike have begun asking whether the rapid growth of data centre infrastructure is having unintended effects on the surrounding environment.
Measuring the impact
Data centres generate significant amounts of heat as thousands of servers and networking systems operate continuously. Cooling infrastructure removes that heat to protect equipment but, in doing so, releases warm air into the surrounding environment.
Researchers are now studying what that means for nearby communities.
A preprint study led by academics at the University of Cambridge analysed decades of satellite data covering data centre locations around the world. According to the research team, the analysis accounted for factors including urbanisation and wider climate change.
After making those adjustments, researchers found an average temperature increase of around 2°C near clusters of data centres.
In some locations temperatures rose by as much as 9°C, although those examples came from facilities in Brazil and Spain rather than the UK.
Slough's new phase
The researchers also argue that Slough represents a different scale of development from the facilities included in much of their study.
Many of the sites analysed were built over the past two decades and typically consume up to 100MW of power. Slough's cluster, by comparison, is already approaching 1GW.
"Slough is almost like an experiment by itself in the sense that the new investments in data centres are bringing to life a new generation of data centres," Andrea Marinoni, Associate Professor at the University of Cambridge and one of the paper's authors, tells The Guardian.
"What we measured were what we can call the first generation of data centres that were the ones that were implemented in the last 20 years. Slough is a different context for the scaling up of data centres, and is something that is quite unprecedented."
Local weather observations appear to reflect the wider trend. A weather station close to the data centre campus recorded temperatures of 36.7°C on one day of the recent heatwave and 36.5°C on the next.
Another weather station further into Slough, away from the concentration of facilities, measured 36.2°C and 34.7°C over the same period.
Turning heat into a resource
While waste heat presents a challenge for neighbouring communities, it could also become an opportunity for the data centre industry.
The UK Government has proposed using surplus heat from data centres to supply district heating networks, similar to systems already widely deployed across Scandinavia.
If implemented, such schemes could reduce energy waste, lower household heating costs and cut emissions associated with conventional gas boilers.
Whether Slough's operators pursue large-scale heat recovery projects is still unclear.
What is certain is that the town's role as one of Europe's most important data centre hubs continues to grow, placing increasing attention on how future campuses can balance expanding digital infrastructure with the needs of the communities around them.
