Smart Inverter Working Group

The Smart Inverter Working Group (SIWG) grew out of a collaboration between the CPUC and California Energy Commission (CEC) in early 2013 that identified the development of advanced inverter functionality as an important strategy to mitigate the impact of high penetrations of distributed energy resources (DERs).The SIWG has pursued development of advanced inverter functionality over three phases. Phase 1 considered autonomous functions that all inverter-connected DERs in California will be required to perform.Phase 2 considered the default protocols for communications between IOUs, DERs, and DER aggregators. Phase 3 is currently considering additional advanced inverter functionality that may or may not require communications.  

For more information on the SIWG, please contact Jeffrey Kwan at .

Upcoming Workshops

Thursday, November 17, 2016 - SIWG Workshop on Adoption of Phase 2 and 3 Recommendations 

SIWG History

SIWG materials, presentations from the previous workshops and links to the video webcast can be found on the CEC’s Rule 21 Smart Inverter Working Group website. 

SIWG Recommendations for Phase 3 Advanced Functions

The SIWG hosted a Phase 3 workshop at CPUC headquarters on September 25, 2015 to discuss additional advanced inverter functions being considered in Phase 3, and to discuss coordination issues between the SIWG and related CPUC proceedings such as the Distribution Resources Plan (R.14-08-013) and the Integrated Distributed Energy Resources (R.14-10-003) proceedings.  The SIWG released its Phase 3 recommendations in March 2016.

SIWG Recommendations for Phase 2 Communication Protocols

The Smart Inverter Working Group released its Phase 2 recommendations for DER communication protocols in February 2015. The CPUC Energy Division is currently working with the IOUs to implement these recommendations in Rule 21, the IOUs’ interconnection technical handbooks, and an IEEE 2030.5 implementation guide.

SIWG Recommendations for Phase 1 Autonomous Functions

In D.14-12-035, the Commission adopted seven functions that smart inverters must perform autonomously. The seven Phase 1 functions will be mandatory for all interconnecting DERs one year from the approval of UL 1741 Supplement SA.  

D.14-12-035 was informed by the SIWG’s Recommendations for Updating the Technical Requirements for Inverters in Distributed Energy Resources document.