Buckinghamshire Council has approved Amazon Web Services' data center at Iver, a few miles east of Slough, Data Center Dynamics reported on 1 October, citing the Bucks Free Press. The project replaces 17 industrial and warehouse buildings at the Ridgeway site with a single two-storey data center, a medium-voltage building, a substation compound with two switchrooms and a generator yard holding 27 backup generators.
Amazon Data Services filed the application in October 2025. It had bought the site in an off-market deal in 2022 for £132.5 million. The filings put the building at 30,525 square metres.
The Generator Yard Was the Sticking Point
Air quality, and the generators in particular, drew most of the objections. Wilson's Media reports that the site lies in an area already under official air pollution controls, and that the council's environmental health officers warned the generators could release pollutants during testing and maintenance runs. Modelling submitted with the application predicted negligible effects at the nearby locations that were assessed. Officers concluded that the need for data centers, the jobs and an expected drop in traffic outweighed the harm.
The approval comes with conditions. Amazon will pay £600,382 towards projects that offset air pollution, must monitor emissions from its generators under an agreed plan, and will spend £73,000 on public footpaths near the site. Details on construction traffic, drainage and water use are still to be submitted.
HVO First, Diesel as Fallback
According to the reports, the generators will run mostly on hydrotreated vegetable oil (HVO), with diesel kept as a secondary fuel for situations where the primary fuel cannot be used safely. Running on two fuels changes more than the fuel contract. Storage, fuel quality checks and the switch-over procedure have to work for two fuels, and the tanks and fuel treatment are planned with that in mind.
The monitoring condition is the other point that will outlast the planning stage. Every monthly test and every maintenance run now leaves a record that the authority can ask to see. For the operator, the test regime and the exhaust system of the generator yard have become part of the permit, not just of the maintenance plan.
On cooling, DCD reports that the building will use direct evaporative cooling with outside air for most of the year, and adiabatic cooling on hot days, fed with rainwater first and mains water as backup.
Sources: Data Center Dynamics, Wilson's Media