🌿ERF

Energy Reuse Factor (ERF), captures the sustainability of exporting energy from the data center which would otherwise be rejected to the atmosphere/environment. Most commonly this energy is in the form of heat produced by the cooling infrastructure, whether it be heated water or air.

Details

Unit: NA / %

Minimum: 0.0

Maximum: 1.0

Ideal: 1.0

Formula

$$ERF= \frac{ENERGY\ REUSED\ OUTSIDE \ DC}{TOTAL\ DC\ ENERGY }$$

Evaluation

The maximum value of 1.0 represents a 100% reuse of energy where as the minimum, 0.0, means no energy is reused. Difficulties in obtaining the value may arise when considering that exiting energy is usually not in the same form as entering energy.

Various uses for the export energy have been suggested and are readily implemented in data centers around the world. They include connecting to local neighborhood heating infrastructure or using the excess heat in greenhouses farms. A data center which implements reuse energy not only wastes less energy, but contributes to less emissions that would have resulted from the energy produced which it replaced.

Sources

[1] HARMONIZING GLOBAL METRICS FOR DATA CENTER ENERGY EFFICIENCY – MARCH 2014 [pdf]