Energy Reuse Factor (ERF)
Description: Energy captured and reused for an alternate purpose outside the data center boundary divided by the total energy consumed in a data center (Annual)
Assesses utilization of energy used in the data center (annual).
Purpose: Defines Energy Reuse Factor (ERF) as a KPI for quantifying utilization of the data center energy for an alternate purpose outside the data center boundary.
Calculation formula:
also ERF=(ReuseEnergy)/(TotalEnergy)
Components
E_reuse – Heat produced by the DC which is harvested and used outside of the DC
E_dc – Total DC energy consumption
Measurement points:
Incoming building utility provider power meter – kWh.
Energy received and used based on either internal or external metering. Output from specialised BMS or intelligent DCIM software.
Actionable insights
ERF offers an operational view of the amount of energy flowing into a data center which is subsequently ‘reused’ for non-data center activities. This then allows the ability to monitor and ideally increase the amount of energy exhausted (and therefore being ‘wasted’), in the form of heat to be re-used in a way that can reduce (offset) the energy burden normally associated with other operations. Examples include, supply of heat to district heating systems, warming greenhouses, heating swimming pools etc.
Note: Energy Reuse Effectiveness (ERE), which is not part of the standard, can be calculated from PUE multiplied by Energy Reuse Factor (ERF).
ERE = PUE × ERF, 1 ≤ ERE