Objective - Establish interoperable electrical and information exchange standards, performance models, and measurement methods for smart grid and microgrid integration of high-speed battery storage systems focused on community and customer domain devices (including electric vehicles as grid storage).
What is the Technical Idea? The rapid rise in distributed, renewable energy resources, including residential photovoltaics, is driving fundamental changes in our electrical infrastructure, including new operational and regulatory requirements and new expectations among consumers. The future grid that will emerge from this rapidlyevolving landscape has new measurement and interoperability challenges that are being addressed through NIST’s smart grid test bed project portfolio, with one exception. That exception is the essential role that energy storage capability must play in providing for a stable and manageable future grid. This proposed new project addresses that gap by adding high-power storage and associated energy management methodologies to the microgrid interoperability testbed, and by using this Energy Storage Systems (ESS) to conduct research on the role of storage in microgrid island mode operation and grid support during grid-conneceted mode. The project will develop technology underpinnings of ESS energy mananment systems (EMS), grid storage application performance models, and the measurement methods and standards needed for effective grid integration and utilization of ESS devices.
Distributed highspeed ESS devices utilizing advanced battery technologies and smart inverter interconnection equipment can in principal simultaneously provide value for many applications, thus increasing the value proposition of the installed systems; and hence incent pervasive deployment. However, this will require a new EMS paradigm where the highly distributed ESS devices provide fast local customer and distribution grid support needed for resiliency and power quality, while simultionsly participating in wide area grid support for stability and capacity utilization. The NIST project will address the interoperability requirements for customer and grid support functions of of ESS including the following:
The local customer and distribution system applications for highspeed storage include improving power quality, smoothing ramprates of photovoltaicsolar from clouds, and enabling microgrid operation for outages. In microgrid applications, distributed storage can be a primary enabler by providing generation during short outages and transitions to island mode, and by enabling local rotating generators to operate at more optimal power levels and cycling rates. The same distributed storage system can smooth ramp rates of local solar generators that can affect local power quality and can interfere with local distribution system devices and operations (Ramp rate regulatory requirements are being considered by California PUC Rule 21 Smart Inverter Working Group). High speed distributed storage systems can reduce the ramp rates to no faster than a minute to meet utility needs, while also allowing photovoltaic solar system integrators to use maximum power point tracking to capture all available solar energy.
Power Transmission and Distribution delivery system assets typically must be sized for the peak power level that is only needed for a short period of time during the day. Aggregated highspeed distributed storage can level the peak power flowing through the constricted grid interconnections, thus reducing the capital equipment investment needed to service peak load events. In 2011, a FERC ruling permitted higher market rates for participation in fast frequency regulation that can be provided by highspeed battery storage systems, in contrast to the lower market rates for the less valuable slower response frequency regulation that is provided by rotating machine generators. In 2014, the California Public Utility Commission in response to California legislation set a total state energy storage target of 1.3 GW by 2020. These are major drivers (and mandates) for rapid deployment of highspeed storage that can also provide the other benefits discussed above.
What is the Research Plan? The NIST distributed storage project will provide interoperable standards, measurement methods and data that will enable battery-based distributed Smart Grid Storage Systems to capitalize on multiple value streams, and will provide certainty in markets by better defining the cost and value of providing the various grid storage functions.
In 2009, NIST authored and chaired the Smart Grid Interoperability Panel (SGIP) priority action plan that coordinated standards for Distributed Energy Resources with a focus on distributed storage. NIST has continued to provide leadership in this area through the SGIP Distributed Renewables, Generation and Storage Domain Expert Working Group (DRGS DEWG). The NIST distributed storage project will continue to participate and provide leadership on distributed storage system standards working groups focused on interconnection standards, information model standards, and test and safety standards including:
- IEEE P1547: “Draft Standard for Interconnection and Interoperability of Distributed Energy Resources with Associated Electric Power Systems Interfaces (full revision of IEEE Std 1547)”
- IEC TC 57 WG 17: “Communications Systems for Distributed Energy Resources (DER)”
- IEEE P2030.2 “Draft Guide for the Interoperability of Energy Storage Systems Integrated with the Electric Power Infrastructure”
- IEEE P2030.3 “Standard for Test Procedures for Electric Energy Storage Equipment and Systems for Electric Power Systems Applications”
- SAE J2836/3 “PEV Communicating as a Distributed Energy Resource US TAG to IEC TC120 on “Electrical Energy Storage Systems”
- Member of DOE OE Working Group on “Energy Storage Safety and Validation”
- Member of “EPRI Energy Storage Integration Council”
- Member of Working Group on “Performance Measurements for Energy Storage Systems Integrated with Microgrids”
In 2011, NIST convened the High Megawatt PCS workshop at the Pentagon to aid in identifying “PCS Architectures for PEV Fleets as Grid Storage” (http://www.nist.gov/pml/high_megawatt/jun2011_workshop.cfm). This was part of the DOD goal to mitigate the cost of PEVs at military bases by using them as grid storage when they are not being driven (http://www.whitehouse.gov/blog/2011/09/09/air-force-jumpstarts-electric-...). The NIST project will demonstrate interoperability of distributed smart grid battery storage systems for the use cases and standards discussed above. The project leverages other projects within the NIST Smart Grid Office research portfolio and the unique NIST smart grid testbed including the grid scenario emulator and Microgrid/PCS lab.