Where Power Usage Effectiveness (PUE) is the standard for determining the energy efficiency of a data centre, Partial Power Usage Effectiveness (pPUE) is the standard for identifying a specific part of energy efficiency in a data centre. pPUE reflects the ratio of the total energy consumed by a data centre’s subsystem to the IT load for 12 months.
Subsystems include lighting, cooling, an uninterruptible power supply (UPS) and everything that contributes to a safe data centre.
As a manufacturer of climate solutions, STULZ often uses pPUE. This calculation is actually more useful than the PUE to get a good picture of the energy efficiency of a specific subsystem. It is important to take other influence variables into account, such as the location and the prevailing temperatures or climate there.
The calculation of pPUE is as follows: The total energy of all IT equipment is added to the energy of a specific subsystem and then divided by the total energy of the total system. This is how only the energy that goes into the specific subsystem remains.
The pPUE is calculated twice. Once before a specific climate solution has been added and once after it has been added, to see how much energy is saved.
pPUE = PIT + Psubarea/PIT