This piece was originally published in the July 2016 issue of electroindustry.
Steve Griffith, PMP, Industry Director, NEMA
The application and use of energy storage systems (ESSs) has grown dramatically in grid-scale and building-based systems. These systems are capable of doing much more beyond storing power when there is less demand and helping smooth out supply-and-demand challenges.
As a case in point, entities that are considering the application and use of ESSs need accurate, reliable, and comparable data on the performance of such systems today and in the future, as storage technologies evolve and their range of applications increases.
More than four years ago, the Pacific Northwest National Laboratory (PNNL) and Sandia National Laboratories initiated and developed a protocol to measure and express ESS performance through the Energy Storage Performance Protocol Working Group. That initial effort filled a significant gap in the ability to measure and express energy storage system performance and culminated in the publication of a protocol in late 2012. The effort continued through enhancements to the protocol in June 2014 and April 2016, under the leadership of the Energy Storage Systems Program within the Department of Energy’s Office of Electricity Delivery and Energy Reliability.
NEMA was instrumental in providing leadership overall in the development of the document (Protocol for Uniformly Measuring and Expressing the Performance of Energy Storage Systems) and on the metrics task force.
The April 2016 protocol addresses how ESSs perform in the original (June 2012) two areas—peak shaving and frequency regulation—as well as six other applications: microgrids (added in June 2014), photovoltaic smoothing, power quality, volt/VAR, frequency control, and renewables firming (added in April 2016).
In addition to covering eight applications, the April 2016 protocol is enhanced to provide for additional performance metrics and specifications, improved accuracy, and better organization for easier application. Further enhancements are planned based on experiences gained in applying the protocol directly and input from U.S. and international efforts associated with adapting the protocol into more formalized standards.
NEMA, through its ESS Section, will lead an effort to formalize the PNNL document into an ANSI/NEMA standard. NEMA currently holds the secretariat for the ANSI Accredited Standards Committee on Energy Storage Systems, which will form the consensus body for this standards activity.
NEMA also will work with the U.S. Technical Advisory Group to IEC Technical Committee120 Electrical Energy Storage Systems and have them consider it a basis for future U.S. submissions to the draft of the IEC standard covering ESS performance measurement.