guide
Capacity definitions: IT, facility, grid and thermal MW
Data centre capacity numbers mix very different things: IT load, facility power, grid connection, thermal cooling capacity and battery energy. This guide explains each measure, how they relate, and the roll-up rules CoolPower Index uses so that unlike numbers are never added together.
IT capacity (MW IT)
Power available to servers, storage and network equipment. EU Delegated Regulation 2024/1364 defines installed IT power demand as the sum of nominal power demand in kW of network, server and storage equipment on the computer room floor, and separately defines rated IT load. Reporting there applies to sites with installed IT power demand of at least 500 kW.
Facility power (MW facility)
IT load plus cooling, power losses, lighting and other building loads. Facility power divided by IT power on an energy basis over a year gives PUE. A 100 MW IT campus therefore needs well over 100 MW at the meter.
Grid capacity (MW or MVA grid)
The connection capacity agreed with the network operator. It can be phased, may be in MVA rather than MW, and often exceeds near-term load. Connection offers are not the same as built capacity.
Thermal capacity (kW or MW thermal)
Heat a cooling product can remove at stated conditions. A 2 MW CDU removes 2 MW of heat at its rating point, not 2 MW of IT load in every case. Chillers and dry coolers are also rated thermally, at an ambient and fluid temperature.
Power vs energy (MW vs MWh)
MW is a rate. MWh is an amount of energy. A battery may be 100 MW and 400 MWh. These must never be added. Gensets add another layer: kVA is apparent power, kW real power, and standby, prime and continuous ratings differ.
Roll-up rules used on this site
Never add IT, facility, grid and thermal figures together. Never count a parent campus and its child buildings both. Company-level claims (for example a portfolio total) are not summed with project-level figures. Unknown values stay not disclosed, never zero. Each figure carries its class, unit, status (announced, under construction, operational) and source.
Practical checks
When a headline says a campus is 1 GW, ask whether that is IT, facility or grid, whether it is phased, and what is operational today. NVIDIA describes 1 MW IT racks from 2027, which is a per-rack IT figure and says nothing about site totals.