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Half the power in a data center never touches a computer
💡 PUE reveals how much of a data center's electricity is pure overhead — mostly cooling — with 1.0 being perfect and cloud giants pushing toward 1.1.
When you spin up a cloud server, you pay for its computation — but the building around it burns extra electricity just to keep that chip alive. The industry measures this waste with a single number called PUE (Power Usage Effectiveness): total facility energy divided by the energy that actually reaches the IT equipment.
A perfect PUE is 1.0 — every watt goes to servers, none to overhead. That's physically impossible, because chips turn electricity into heat, and heat has to be removed. The biggest culprit is cooling: chillers, fans, and air handlers can consume nearly as much power as the servers themselves. Add power-conversion losses and lighting, and a typical older data center runs around PUE 1.5–2.0 — meaning up to half the electricity is overhead.
This is why hyperscalers obsess over it. Companies like Google report fleet-wide PUEs near 1.1, achieved with tricks like running hotter (raising the server room temperature), free cooling with outside air, and locating data centers in cold climates or near water. Every fraction below 1.5 is millions of dollars — and megawatts — saved.