BS/EN 50600-4-3-2016 pdf download.Information technology Data centre facilities and infrastructures
Part 4-3: Renewable Energy Factor.
Eren is the RE in kWh owned and controlled by a data centre (i.e. any energy for which the data centre owns the legal right to the environmental attributes of renewable generation) including that:
a) generated on-site of the data centre and whose legal rights to the environmental attributes of RE are retired in the data centre (so, that is no longer a contractual instrument to be traded, or that is no longer a possession of the last owner or the renewable certificate system administrator);
NOTE 1 “Retired is an official term that means consumed.
b) obtained by procurement of RE certificates and retired in the data centre;
C) portion of utility electricity, defined as RE, provided the data centre has obtained documented written evidence from the source utility provider(s) that the energy supplied, for the reporting period in question;
NOTE 2 This excludes RE generated in a data centre site but whose legal rights to the environmental attributes of RE were sold to other parties or the market.
EDC is the total data centre energy consumption (annual) in kWh.
REF shall have a maximum value of 1,00, indicating 100 % of the total data centre energy is RE.
On-site generation of RE beyond the need of the data centre shall not be accounted for REF. Therefore, a value greater than 100 is not possible.
Because the RE content of the KPI is based on legal ownership of the rights to the environmental benefits, it is important to clarify that the location of energy source does not change the calculation of the REF.
For example,
a) where a data centre has a solar panel on its roof to generate electricity and the data centre sells the RE certificates associated with this electricity, the contribution of the solar panel is excluded as RE within the calculation of the REF;
b) a data centre that receives electricity entirely from a coal-fired plant can purchase RE certificates to offset the entire electric use, and these certificates are included as RE within the calculation of the REF.
Examples of REF calculation are included in Annex B.
5.2 Total data centre energy consumption
The data centre under consideration shall be viewed at as a system defined by interfaces through which energy flows.
The following forms of energy shall to be metered at the interfaces:
a) electricity;
b) gaseous fuel;
— hydrogen: 38,9 kWh/kg;
— bioethanol: 6 kWh/I.
The energy contribution of fluids for cooling shall be measured using heat meters (providing information on
flow rate and differential temperature) and multiplied by the relevant conversion factor of the system used to
provide the fluid used.
If technical subsystems, e.g. on-site co-generation of heat and electricity, have meters at their output, they are considered external to the system. If technical subsystems have meters at their input or only have partial metering at their outputs, they are considered internal to the system.
5.3 Total data centre energy consumption in mixed-use buildings
The total data centre energy consumption for data centres in mixed-used buildings shall be calculated on the energy use of the data centre as system only if metering of all shared technical subsystems allows separation of energy usage.
If energy use of shared technical subsystems cannot be separated, total data centre energy usage shall comprise the building in total. The impact on REF should be counteracted by implementing the necessary meters for separation.
6 Measurement of Renewable Energy Factor
Measurements of Eren and EDC shall be undertaken using either:
a) “watt meters with the capability to report energy use, or
b) kilowatt-hour (kWh) meters that report the true energy (true mis), via the simultaneous measurement of the voltage, current, and power factor over time.
NOTE Kilovolt-ampere (kVA), the product of voltage and current, is not an acceptable measurement. Although the product of volts and amperes mathematically results in watts, “tru& energy is determined by integrating a power factor corrected value of volts and amperes. The frequency, phase variance and load reachon cause energy calculation difference between apparent energy and “tru& energy. The error is inherently significant when power delivery includes alternating current (AC). Kilovolt-ampere (kVA) measurements can be used for other functions in the data centre; however, kVA is insufficient for efficiency measurements
Energy input from local renewable sources also shall be measured with the same procedure as total data centre energy consumption.
REF shall be determined as an annualized value. The calculation of REF requires the recording and documenting of E and over a coincident period of twelve months. This standard does not specify the frequency of measurements of E and E, since REF is calculated on an annual timeframe. However, the frequency of measurement employed will define the timing of subsequent PUE calculations on a rolling annual basis.BS/EN 50600-4-3-2016 pdf download.