Impact Assessment and Secure Implementation of California Rule 21 Phase 3 Smart Inverter Functions
February 25, 2021
Energy Research and Development (500)
Electric Program Investment Charge - EPIC
Ajit Anbiah Renjit, Tom Tansy, Bob Fox, Candace Suh Lee, Jouni Peppanen, Steven Coley, Tanguy Hubert, Hamed Valizadeh Haghi, Zachary Pecenak, Matthew Rylander, Jan Kleissl, Lloyd Cibulka, Steve Wheat, Gregory Thompson
This document is the final report for the Impact Assessment and Secure Implementation of California Rule 21 Phase 3 Smart Inverter Functions project conducted by the Electric Power Research Institute (EPRI) to support high PV penetration. A diverse team of stakeholders carried out the project, including EPRI, SunSpec Alliance, University of California, San Diego (UCSD), Sunrun, SMA, Enphase Energy, Kyrio, SolarEdge, ABB, and OpenEGrid.
The project analyzed a representative set of California distribution feeders to determine the level and duration of control needed to gain a 25 percent increase in hosting capacity above the baseline achieved with Rule 21 Phase 1 functions such as power factor and volt-var control. The solar availability information was used with modeling to determine the statistical time and locational probabilities of how the Phase 3 functions would operate. This information was used to conduct a comprehensive economic analysis to determine the value to the grid and compensation means to distributed energy resources asset owners.
Moreover, the project assessed the practicality and applicability of Rule 21 Phase 3 functions by physically incorporating them into residential inverters from SMA and ABB. These inverters were fully evaluated under controlled conditions at the advanced inverter test facility at UCSD. Following this, a field pilot of 57 residential inverters was conducted within San Diego Gas & Electric territory using a Sunrun aggregation system. The project also accomplished developing a certification procedure by which any system or device can be checked for compliance to the IEEE 2030.5 communication standard and Rule 21 smart inverter functions, which is a major step toward achieving interoperability.
The project also established an IEEE 2030.5 Public Key Infrastructure for California, removing a significant impediment for California Rule 21 compliance that protects California grid investments.