E-1: Commissioner James Danly Concurrence Regarding Reliability Standards to Address Inverter-Based Resources

Commissioner James Danly Statement
October 19, 2023
Docket No. RM22-12-000

I concur in today’s order[1] in which we direct NERC to develop new or modified mandatory and enforceable Reliability Standards prior to 2030 in order to address a set of reliability risks we have known about, and been actively discussing, since at least 2016 and about which I have long warned.  Is today’s order important and necessary?  Yes.  Is it timely?  No.  Six of the thirteen documented events occurred in 2021.[2]  The Commission and NERC could have, and should have, acted sooner, particularly since 2030 marks the time at which inverter-based resources (IBRs) “are projected to account for a significant share of the electric energy generated in the United States.”[3]

The reliability risks at issue arise from the rapid, widespread (one might say reckless) addition of IBRs (e.g., wind and solar) to the Bulk-Power System (BPS).[4]  According to NERC, “[t]he rapid interconnection of [BPS]-connected [IBRs] is the most significant driver of grid transformation and poses a high risk to BPS reliability.”[5]  As NERC has explained, “[e]ach event analyzed has identified new performance issues, such as momentary cessation, unwarranted inverter or plant-level tripping issues, controller interactions and instabilities, and other critical performance risks that must be mitigated.”[6]  “Simulations conducted by the NERC Resource Subcommittee demonstrate that the risks to the [BPS] reliability posted by momentary cessation are greater than any of the actual IBR disturbances that NERC has documented since 2016 . . .  These simulation results indicate that IBR momentary cessation occurring in the aggregate can lead to instability, system-wide uncontrolled separation, and voltage collapse.”[7]

NERC has also observed “[m]ultiple recent disturbances that involve the widespread reduction of solar photovoltaic (PV) resources have occurred in California, Utah, and Texas.”[8]  The “first major events involving [battery energy storage system facilities” occurred just last year in March and April, 2022.[9]  The reliable operation of the Bulk-Power System remains imperiled until these issues are addressed.  Time is of the essence. 

Our oversight role requires us to remain vigilant in ensuring that NERC Reliability Standards are timely, efficient, and effective.  Up to nearly fourteen years to establish mandatory and enforceable NERC Reliability Standards to address a known, and potentially catastrophic, risk to the reliability of the BPS is simply too long a time to wait.  And we will have to wait yet longer to learn whether the standards we do ultimately implement end up proving effective.  Who knows what will happen in the meantime.

Better late than never, I suppose.

For these reasons, I respectfully concur.