NERC to Establish Reliability Standards for U.S. Wind, Solar Plants

By Christian Roselund

Federal regulators have ordered the North American Electric Reliability Corporation (NERC) to create new standards for wind plants, solar plants, and other inverter-based resources to prevent them from unexpectedly tripping offline. The new standards must cover the areas of data sharing, model validation, planning and operational studies, and performance requirements, and must also cover implementation.

The Federal Energy Regulatory Commission’s (FERC) Notice of Proposed Rulemaking follows a series of incidents where solar plants have tripped offline at inopportune times. On 9 May 2021, 1,112 megawatts of solar and 36 megawatts of wind spread over 500 miles tripped offline due to a drop in voltage on a line caused by a failure at a gas plant. In its analysis of the “Odessa Incident,” NERC states that the solar and wind going offline was not caused by the fault itself, but due to inverter-level or feeder-level tripping or control system behavior within the wind and solar plants. NERC has also documented several such instances in California, dating back to the failure of 1,200 megawatts of solar plants during the 2016 Blue Cut Fire.

FERC says that this new effort should complement existing voluntary efforts including UL 1741, IEEE 1547-2018, and IEEE 2800-2020. However, voluntary efforts have been unsuccessful efforts to contain this problem. In its analysis of the Odessa Incident in Texas, NERC states that solar and wind plant owners and operators are aware of the guidance materials it has published but have not comprehensively adopted them. FERC also states that the continued occurrence of these events despite voluntary efforts at the state, level, and individual system level, and the risks they pose, mean that there is a need for mandatory reliability standards on a nationwide basis.

FERC will now go through its formal process to finalize this rule. Once it is finalized, NERC will have to submit a compliance filing within 90 days of the effective date of the final rule that includes standards development and implementation plans.

Source: Reliability Standards to Address Inverter-Based Resources (FERC)