Annual energy, cost and carbon for a data center or server room from IT load × PUE, with a measured-PUE mode, EPA eGRID emission rates and LBNL context
Updated October 2026
PUE (power usage effectiveness) is total facility energy divided by the energy used by the IT equipment. A PUE of 1.54 means every kilowatt of servers, storage and network gear brings another 0.54 kW of cooling, power conversion losses, lighting and other overhead. So annual energy = IT load (kW) × PUE × hours ÷ 1,000 MWh, and cost and carbon follow from the price per kWh and the grid’s emission rate.
The published example, reproduced. The 2011 data center metrics task force recommendations, backed by The Green Grid, ASHRAE, Uptime Institute, DOE and EPA’s ENERGY STAR program among others, work through an all-electric site (Case A).
| End use (Case A) | Energy per year |
|---|---|
| IT load | 1,000,000 kWh |
| Power delivery loss | 250,000 kWh |
| Lighting | 50,000 kWh |
| Cooling | 400,000 kWh |
| Other | 5,000 kWh |
| Total | 1,705,000 kWh |
PUE = 1,705,000 ÷ 1,000,000 = 1.705, which the document reports as 1.70. Enter those two totals in the calculator’s measured-energy fields to get the same result.
Default. A facility averaging 1,000 kW of IT load at the 2025 industry average PUE of 1.54 draws 1,540 kW. Running all 8,760 hours of the year, it uses 13,490 MWh. At the July 2026 U.S. industrial electricity price of 9.77¢ per kWh that costs $1,318,012. At the U.S. average grid rate in eGRID2023 it emits about 4,695 metric tons of CO2.
| Figure | Value | Source |
|---|---|---|
| Average annual PUE, global survey | 1.54 in 2025; 1.56 in 2024; 2.50 in 2007 | Uptime Institute (July 2025) |
| U.S. data center electricity use | About 60 TWh (2014-2016); 76 TWh (2018, 1.9%); 176 TWh (2023, 4.4% of U.S. use) | LBNL (Dec. 2024) |
| U.S. projection for 2028 | About 325 to 580 TWh, 6.7% to 12.0% of U.S. use | LBNL (Dec. 2024) |
| U.S. average grid CO2 rate | 767.2 lb per MWh (eGRID2023) | EPA eGRID (2025) |
| State grid CO2 rates | Washington 265.1, Oregon 364.2, California 393.5, Illinois 471.7, Virginia 536.9, Arizona 686.7, Georgia 713.8, Texas 768.3, Ohio 1,063.8 lb/MWh | EPA eGRID2023 |
| Electricity prices, July 2026 | U.S. commercial 14.53¢, industrial 9.77¢ per kWh | EIA Electric Power Monthly |
The default facility’s 13,490 MWh is about 0.0077% of what all U.S. data centers used in 2023. The eGRID rates are annual averages of generation in each state. A facility’s own emissions depend on its utility contract and any clean-power purchases, and on the hours it runs.
| Facility | Facility kW | MWh a year | Cost a year | Metric tons CO2 |
|---|---|---|---|---|
| 1 MW IT, PUE 1.54, U.S. average grid (default) | 1,540 | 13,490 | $1,318,012 | 4,695 |
| 1 MW IT, PUE 1.20, U.S. average grid | 1,200 | 10,512 | $1,027,022 | 3,658 |
| 1 MW IT, PUE 2.00 (older site) | 2,000 | 17,520 | $1,711,704 | 6,097 |
| 1 MW IT, PUE 1.54, Virginia grid | 1,540 | 13,490 | $1,318,012 | 3,285 |
| 1 MW IT, PUE 1.54, Ohio grid | 1,540 | 13,490 | $1,318,012 | 6,510 |
| 50 kW server room, PUE 1.80, commercial rate 14.53¢ | 90 | 788 | $114,555 | 274 |
| 20 MW IT, PUE 1.30, Texas grid | 26,000 | 227,760 | $22,252,152 | 79,373 |
Cutting PUE from 1.54 to 1.20 at 1 MW saves about 2,978 MWh a year with the same servers. The grid matters as much for carbon: the same facility emits about four times as much on Ohio’s grid as on Washington’s.
It assumes a constant average load and a single electricity price. It does not model demand charges, time-of-use rates, on-site generation, backup generator testing, water use or IT equipment refresh. Carbon uses location-based average grid rates, not market-based accounting for renewable energy purchases. For a real facility, use metered data and your utility tariff, and follow the PUE measurement categories in the task force recommendations.