What Is Rule 21
What is Rule 21 California?
California Rule 21 is an interconnection tariff levied by the California Public Utility Commission (CPUC) that sets rules for performance, function, metering, and communications of generation and storage facilities.
Why do you think California has Rule 21 for inverters?
The main impact of Rule 21 for solar installers is that any of your installations in the state of California must now use Rule-compliant inverters. … Dynamic voltage operation must also be enabled so that smart inverters can absorb or input reactive power into the electric grid to maintain stability.
Are grid tie inverters legal in California?
Yes, if you install in California, and if the project in question will connect to a utility grid. Rule 21 requirements apply to any inverter attached to a utility’s grid. Note that each of California’s major utilities (PG&E, SCE, SDG&E) manage their respective jurisdictions regarding Rule 21 interconnection compliance.