Today’s LiveWire Spotlight evaluates NERC’s latest CMEP Practice Guide which outlines the actions expected of Compliance Enforcement Authorities to avoid uneven assessments of violations/penalties for the unreliable use of Battery Energy Storage Systems (BESS) and hybrid resources in BES applications.  NERC sees both technologies as forms of inverter-based systems, whose qualifying criteria appear in the BES Definition, Inclusion I4; i.e., aggregated capacity > 75 MVA @ connection voltages ≥ 100 kV.

As of 4/20/21, the CMEP Practice Guide for Energy Storage Systems “took effect” across the U.S. and Canada.  Clients should expect CEAs to apply the guidance to verify that their inverter-based Facilities and sub-components are properly categorized as BES and non-BES.