Metering and Monitoring

The GSN Project will on focus on carbon reduction through utilization of low carbon intensity power sources. One might suppose that if a power source is 100% green – e.g. wind power – then there is no need to measure consumed power. However, in the context of carbon reduction quantification, that conclusion is invalid, for the following reason. Suppose one desires to quantify carbon reduction for an ICT service that was originally running on computers powered by high carbon intensity power, and which is now running on low carbon intensity power. Logically, one would require measurement of the related carbon emissions both before and after the change of power source. However, in common practice supported by ISO 14064, one may choose to measure over a period of time (e.g. a year) at the low intensity site, and then estimate the carbon emissions that would have resulted had this period of operation taken place in the original high carbon intensity environment. Such an estimate will rest largely on total consumed power at the low intensity site.

1. Requirements

A GSN Node must meet the following three requirements: A. Power utilized by all devices at the node must be fully accounted for at each moment in time into the two categories: “GSN” or “not GSN”. B. All additional information required by the GSN Carbon Measurement Protocol must be available. Typically, this revolves around the carbon intensity of the electricity provider. C. For every service, the GSN node must be able to provide on demand the historical record of instantaneous power usage (at an appropriate sampling rate), together with the values of all additional measurements required by the GSN Carbon Measurement Protocol. Requirement C will be formulated as a carbon footprint reporting standard for GSN nodes, at the granularity of individual services.

2. Tools

Power Distribution Units (PDU) and power meters must have a Telnet or SNMP interface providing per-outlet power information. The PDUs that will be supported:s · ServerTech POPS · Raritan Dominion PX The UPS Devices that will be supported: · APC Smart UPS Middleware must be able to further break down power usage to the granularity of individual services. The GSN Project will start with simple estimates, and will subsequently try to improve such estimates, based on middleware that interacts with virtual machine hypervisors. The basic idea is to relate the per-service attribution of host machine loading to the host machine’s power consumption, thereby deriving the percentage of power attributable to each VM.