Impact Assessment & Secure Implementation of California Rule 21 Phase 3 Smart Inverter Functions to Support High PV Penetration

Grid Decarbonization and Decentralization Variable Renewable Generation

Electric Power Research Institute, Inc.

Recipient

Palo Alto, CA

Recipient Location

13th

Senate District

23rd

Assembly District

beenhere

$2,899,193

Amount Spent

closed

Completed

Project Status

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Project Result

In 2020, the project team continued the evaluation of two commercial smart inverters for Phase III compliance. The lab test at the University of California, San Diego (UCSD) was also leveraged to conduct cyber security testing (penetration testing). The test results were aimed at providing guidelines to California's DER stakeholders about safe and secure deployment of smart inverter communications. A proof of concept for cyber secure communications was established, 50 residential customers were recruited for the field demonstration of Rule 21 Phase III functions, and communication and control systems to update Phase III functions was successfully established. In March 2020 all testing was completed. The project concluded successfully in September 2020 and the final report was published in December 2020.

The Issue

California Rule 21 was revised to include autonomous device control, data communication, and dynamic electrical control functions for smart inverters. A number of additional functions with the potential to substantially increase the grid's solar hosting capacity are deferred to the third phase, the timeline for which is uncertain. Phase III includes advanced functions that affect the real power produced by solar PV systems. There are both technical and economic questions that must be answered before these capabilities are to come into use.

Project Innovation

This project will comprehensively evaluate the smart inverter Phase III functions. The process includes computer modeling of California distribution circuits for economic analysis, implementation of Phase III functions in multiple inverter brands, laboratory testing, and field pilot testing. An economic analysis will build on the technical findings from the computer modeling, identifying the impact to the asset owner, performing an economic valuation of these impacts, and providing guidance regarding potential compensation. A comprehensive cyber security assessment of the communication system will be performed and key public infrastructure will be established to support the cyber security needs in California.

Project Benefits

This project will help overcome three major barriers to achieving the state's energy goals by: 1) proving that CA Rule 21 Phase III functions can be deployed feasibly, safely and predictably via standardization; 2) demonstrating that grid penetration levels can be increased by 25% or more via use of the Phase III advanced control functions; and 3) enabling secure, scalable and affordable cyber security infrastructure that can make the grid safer and more reliable.

Reliability

This project delivers standardized DER control functions that minimize and mitigate reverse power flows, voltage sags/dips, and other conditions that degrade grid stability and DER performance, thus increasing grid reliability and increasing the availability of access to solar energy.

Safety

The standardized methodology for demonstrating compliance to Rule 21 Phase III requirements eliminates the variability implied by proprietary solutions and enables dynamic electrical control functions to be deployed safely at scale. The availability of cyber security best practices and a public key infrastructure ensures that common security pitfalls are avoided as compliant systems are deployed in the field.