Gigawatt Ledger · one-page briefing
Campus profile Operating
Slough / West London cluster
Equinix · Ark · Virtus · Microsoft · Slough, England, United Kingdom
The resource footprint
Modelled averageIn one day, this campus consumes about
5.9950-metre swimming pools
Filled with the volume of water consumed by the campus and its electricity supply.
The actual estimate3,952,832 US gallons consumed
Power-plant water may come from a different watershed. This is a volume comparison, not a claim that households lose this water.
At current operating capacity · Annual model spread evenly over time, not a live meter. Site estimates may differ by roughly ±40%.
Comparison sizes & sources
One pool = 50 × 25 × 2 metres = 2.5 million litres (about 660,430 US gallons). Pool depths vary; this is a defined comparison size.
One home-year = 10,791 kWh, the EIA’s 2022 average US residential electricity purchases. This excludes electricity generated at home and is a fixed US benchmark for all sites.
One car-year = 4.6 tonnes CO₂, the EPA’s typical passenger vehicle tailpipe estimate. The campus model is in CO₂e; the comparison expresses approximate climate scale, not equal mixtures of pollutants.
Monthly values are annual totals ÷ 12; daily values are annual totals ÷ 365. Actual demand varies. Comparisons cover the whole campus, including non-AI uses.
Water: see the numbers and sources
This is water used up, mainly through evaporation. Power-generation water may be used in a different watershed.
- Pressure on local water
- High — a regional measure of demand compared with available water
- Where the water comes from
- Municipal potable supply
- Cooling
- Mixed free cooling and evaporative; adiabatic on hot days
- Basis
- Modelled from cooling design — WUE 0.43 L/kWh
Air: see the numbers and sources
The totals include nitrogen oxides, sulphur dioxide and fine particles. They cover both this site and the power plants supplying it.
- Health range
- $15.7–44.3 million a year. Lower bound is EASIUR national mid-range; upper is EPA benefit-per-ton at a ~$12M VSL.
- Statistical deaths
- 3.69 a year at that VSL — a national-average conversion from tons, not a local concentration study.
- Equals
- 693,792 cars of NOx
- Where it burns
- Netherlands — TenneT
- Generation mix
- Gas 38 · Wind 25 · Solar 17 · Coal 8
- Diesel backup
- Diesel backup is not yet counted for this campus, so on-site air figures are a floor.
- CO₂e
- 1,487 kt/yr — climate, not air quality
The project, approvals and community concerns
- Who asked for it
- Financial institutions, UK government cloud and the hyperscalers' UK regions
- Who approved it
- Slough Borough Council; the UK designated data centers Critical National Infrastructure in 2024 and created AI Growth Zones to fast-track siting; grid connection queues in West London have delayed housing developments
- What it serves
- UK cloud regions, financial trading infrastructure and European peering
- IT capacity
- 900 MW current capacity / 1,500 MW full-build scenario
Data center demand in West London was significant enough that the Greater London Authority warned in 2022 it was blocking new housing connections until the 2030s. Britain's response was to speed up data centers rather than slow them.
Keep this guide handy
51.5100°, -0.6000°
Quote or share these estimates
Gigawatt Ledger (2026). Slough / West London cluster: water and air. https://gigawatt-ledger.pages.dev/site/london/. Modelled from disclosed capacity; site-level error ±40%.
Include the estimate’s date, whether it describes current or proposed capacity, and its uncertainty. Get an embeddable card.
Gigawatt Ledger · September 2026. Water and air figures are estimated from public records and disclosed capacity. How we calculate them · Use this in your community.