What is data centre energy consumption?
Data centre energy consumption is the electricity a data centre draws for its IT equipment plus overhead such as cooling and power distribution.
Full guideData centre energy consumption: how much power AI is addingWhy it matters
Total facility energy has two parts. The IT equipment covers computation, memory, storage and networking. Facility overhead covers cooling, lighting and power distribution. The ratio of total facility energy to IT energy is PUE. Energy is the base figure from which a data centre's carbon emissions and water use are worked out.
For a cloud customer, the useful figure is not the whole building but the share their own workloads draw. Providers do not report it per workload, so it has to be estimated from usage.
An example
Take the same virtual machine running for a month in two regions. Its IT electricity is identical, because the hardware is the same. In a data centre with a PUE of 1.1, overhead adds 10% on top. In one with a PUE of 1.5, it adds 50%, so the same workload draws more total energy, and usually emits more carbon, in the less efficient facility. (Illustrative figures.)
How Greenpixie measures it
Cloud billing data does not show how much electricity a workload draws. Greenpixie works it out from the hardware behind each SKU:
- map each SKU to its processor, memory, drives and accelerators
- estimate IT electricity from published whole-server power measurements
- apply a fixed operating point, or the provider's baseline for burstable instances, as billing data states no utilisation
- multiply by the region's PUE to get total facility energy
Usage emissions are then total facility energy multiplied by the grid carbon intensity for the region and time period, on a location-based basis.