California’s aggressive inverter requirements under the CA Rule 21 deadline went into play on June 22, 2020.
California Rule 21 Interconnection
Rule 21 Phase 2 communications and Phase 3 smart inverter requirements are now in effect. All major inverter companies that operate in California have been rolling out new inverters and firmware packages to abide by the new requirements.
Rule 21 contains provisions governing the multiple aspects of interconnection, including:
Procedures and timeframes for reviewing applications.
Fee schedules for processing applications and perform impact studies.
Pro forma application and agreement forms.
Allocation of interconnection costs.
Provisions specific to net energy metered facilities.
Technical operating parameters.
Certification and testing criteria.
Technical requirements for inverters.
Metering and monitoring requirements.
Procedures for dispute resolution.
Interconnection of Energy Storage Systems
In September, the Public Utilities Commission (PUC) revised its Rule 21 storage interconnection policy. The Revisions regarding the interconnection of energy storage systems include limited export to the grid and provide more clarity on how these inverters are expected to operate. These regulations will develop easier and more cost-effective methods to limit export.
Major revisions include:
1. The option to include custom interconnection operation plans for energy storage systems. This allows storage systems to feed to the grid during high-demand hours that will benefit both the grid and the homeowner.
2. Allowing customers who request interconnection to view grid condition data to plan their energy usage from their storage systems around peak times, lightening the grid’s load.
3. More unique interconnection policies that complement the advancements in modern storage systems.
Rule 21 is allowing smart inverters to be utilized at their full potential. With new application processes for energy storage systems and more transparent grid data, California is on target to have a next-generation energy grid with the ability for residents to customize their energy interactions with the grid.
For the detailed revisions, see the CA Rule 21 Amendments.