International Development of Energy Storage Interoperability Test Protocols for Photovoltaic Integration

As variable, non-dispatchable photovoltaic power continues to displace traditional generation assets, additional resources are needed to control bulk and local power systems. One highly versatile option for providing frequency and voltage stability is to incorporate Energy Storage Systems (ESSs) at the distribution-level. Deployment of these technologies is expected to increase rapidly as time-of-use pricing and self-consumption requirements become wide-spread and provide greater financial incentives. Japanese, European and American stakeholders are working on the standardization of interoperability certification protocols for many grid support functions to validate the Distributed Energy Resource (DER) operations and communications within the power system. Specifically, in this project, Smart Grid International Research Facility Network (SIRFN) laboratories—Sandia National Laboratories (SNL), Austrian Institute of Technology (AIT), Ricerca sul Sistema Energetico (RSE), and National Institute of Advanced Industrial Science and Technology (AIST) Fukushima Renewable Energy Institute (FREA)—are collaborating to create a concise set of test protocols for evaluating the ESS interoperability and functionality. First, a survey of grid-support standards and use cases from several countries was completed. Then the grid support functions were condensed to the unique set of ESS capabilities and organized by function, control signal requirements, and response requirements. From this list, draft certification protocols were written to enable advanced interoperable ESSs covering this range of capabilities to better support photovoltaic and renewable energy integration. An overview of the protocol development process along with preliminary ESS test results for four initial functions (active power, fixed power factor, volt-var, and frequency-watt) is presented. This work is expected to provide the basis of an international testing standard for ESS grid-support functions in the future.