The American National Standards Institute has approved ANSI/SCTE 213 2015, "Edge and Core Facilities Energy Metrics." The document is intended to provide a metric to help operators measure how effective changes in the service impact energy consumption from both a high level and functional work perspective.
The standard is available at http://www.scte.org/SCTE/Standards/Download/SCTE/Standards/Download_SCTE_Standards.aspx?hkey=63914a25-0f85-4d74-8181-c1b642039ad7.