Carbon Usage Effectiveness (CUE)
A metric defined by the Green Grid, which is a measure of data center sustainability in terms of data center specific carbon emissions. CUE is calculated by dividing the total CO2 emissions caused by total data center energy by the energy consumption of the IT computing equipment. An alternative way to calculate CUE is by multiplying the data center’s annual PUE by the Carbon Emissions Factor for the region as determined by the EPA. The units of CUE are kilograms of carbon dioxide per kilowatt-hour.