Google Data Centers — Efficiency (PUE reporting and methodology)

Overview

Google publishes its fleet PUE per campus with quarterly and trailing-twelve-month (TTM) values. The 2025 fleet-wide TTM PUE is 1.09, with 2025 quarterly values between 1.08 and 1.11. Google presents this as 83% less overhead energy than the industry average, set against the Uptime 2025 average PUE of 1.54. The figures are the company's own statement; the record has no independent audit information.

The page's value is in explaining the boundary. A campus enters the report only once it has at least 5 MW of IT load and stable operations, and TTM needs 12 months of data (historically 6 months above 5 MW). The overhead scope is unusually broad: substations, transformers, water treatment plants, accessory buildings such as cafeterias and gyms, and office space all count. Its calculation is aligned with The Green Grid guidance.

The historical notes carry two realistic lessons. New facilities run above design PUE because of commissioning, partial load and lack of tuning. Campuses also differ: in 2021 the range ran from 1.07 in Oregon to 1.16 in Alabama. So 1.09 is the average of a mature, heavily loaded hyperscale fleet and should not be taken as a target for a new, partially loaded facility.

Key points

1. 2025 fleet-wide TTM PUE 1.09; 2025 quarterly values 1.08-1.11.
2. Google claims 83% less overhead energy than the industry average (Uptime 2025: PUE 1.54).
3. Reporting threshold: campuses with >= 5 MW IT load; TTM only after 12 months of data (historically 6 months above 5 MW).
4. Overhead includes substations, transformers, water treatment, accessory buildings (cafeterias, gyms) and offices.
5. Example campus TTM PUE range: 1.07 (Oregon) to 1.16 (Alabama) in 2021.
6. New facilities run above design PUE because of commissioning, partial load and lack of tuning.

Using it in design

• In the efficiency dashboard show three PUE references: design PUE, partial-load PUE (at 25/50/75% IT load) and benchmarks (Google 1.09 hyperscale; Uptime 1.54 industry).
• Let users choose the PUE boundary (include or exclude MV substation and transformer losses, offices) and label results with it, mirroring Google's inclusive method.
• Set a new facility's target PUE from its partial-load curve, not from 1.09.

Who should read it

Energy engineers and decision makers who set PUE targets and argue about boundary definitions.

Related standards

• ISO/IEC 30134-2
• The Green Grid PUE
• EN 50600-4-2

Publication details

Authors

Google

Publisher

Google

Year

2026

Document language

English

Source type

Expert / community

Access

Free to read

Licence

Copyright retained; citation only — the publisher’s terms apply to the original document

Citation