New FERC Orders Will Change Regulatory Process for Inverter Based Resources

The Federal Energy Regulatory Commission (FERC) recently proposed actions to keep the regulatory process and requirements ahead of reliability risks resulting from the accelerated deployment of Inverter Based Resources (IBR) based solar, wind and battery storage projects.  FERC’s actions call for the North American Electric Reliability Corporation (NERC) to develop a plan to register IBR technology-based equipment.

Additionally, FERC proposes to accelerate the development of standards-related to IBR facilities data sharing, modeling, studies and performance requirements. TRC clients are advised to follow these developments closely, as FERC’s actions will substantially increase registration and compliance requirements.

Background

IBR technology projects are not directly synchronized to the electric power system and must be programmed to “ride through” disturbances to avoid tripping offline during routine system disturbances. The current power system was designed with the generation fleet consisting predominately of synchronous generation that through inertia would ride through disturbance events such as tripping and reclosing of transmission lines. However, based on numerous system disturbances reported by NERC linked to IBR technology, FERC has become concerned that the existing Reliability Standards inadequately address the aggregate impact risk to reliability created by IBR deployment. For example on December 9, 2022 NERC and Texas Regional Entity issued their Events Analysis Report on the second Odessa, Texas area disturbance which outlines in great detail the failure modes and  reliability risks resulting from failure to coordinate Inverter based resources control systems. The report outlines numerous immediate actions required to assure the preservation of reliability through the industry transition to renewable resources.

To address these concerns, FERC recently took the actions summarized below.

NERC Registration of Inverter-Based Resources

In its Registration of Inverter-Based Resources Order, FERC addresses the aggregate reliability impact of the subset of renewable projects currently exempt from NERC’s Reliability Standards. Many IBRs are exempt because they do not meet the “bright line” test requiring them to register with NERC (i.e., if the generating facility’s aggregate capacity exceeds 75 MVA sharing a point of interconnection to the transmission system at a voltage at or above 100 kV). NERC has found in several instances that the aggregate impact of such IBRs tripping offline can make recovery from the disturbance more difficult.

To address this demonstrated gap in the reliability regulations, FERC directed NERC to submit a “work plan” to identify and register unregistered IBRs that, “in the aggregate, have a material impact on the reliable operation of the Bulk-Power System.”  NERC must submit its work plan by February 15, 2023. The order provides that all such IBR owners and operators will be identified and registered within three years of FERC approving NERC’s work plan.

Many IBRs connecting to the Bulk-Power System do not individually meet the current Bulk Electric System (BES) definition, and thus, are not registered with NERC. This means that those IBRs below the BES threshold currently are not required to comply with mandatory Reliability Standards or respond to NERC alerts. TRC clients are advised to stay informed regarding NERC’s plans to bring these IBR projects into the regulatory framework.

Proposal to Require Reliability Standards to Address Inverter-Based Resources

In its proposal to address Reliability Standards for IBRs, FERC directed NERC to submit new or modified standards to tackle four issues:

• Data Sharing – Require generator owners, transmission owners, and distribution providers to share validated modeling, planning, operations, and disturbance monitoring data for IBRs with system operators and planners.
• Model Validation – Ensure that IBR models are comprehensive, validated, and timely, so that they can adequately predict the behavior of all IBRs and their impacts on reliability.
• Planning and Operational Studies – Ensure that validated IBR models are included in planning and operational studies to assess IBRs’ reliability impacts, both individually and taken together.
• Performance Requirements – Ensure that registered IBRs provide frequency and voltage support during frequency and voltage excursions adequate to contribute toward the overall system needs

The industry is preparing comments on FERC’s proposal to require NERC to create new IBR related Reliability Standards. FERC also proposes that once FERC issues a final rule, NERC must submit the new or modified Reliability Standards for FERC approval.

Resources

• FERC Order on Registration of Inverter-Based Resources
• FERC NOPR on Reliability Standards to Address Inverter-Based Resources
• TRC Services – NERC Compliance

Your Trusted Regulatory Advisor:

The forgoing FERC actions are significant regulatory events. TRC closely follows the national and state regulatory trends in all regions of North America. Our approach to power system engineering, planning, design, construction and commissioning testing, balances solutions that incorporate industry reliability risk trends, mandatory reliability standard requirements, regulatory guidance, compliance obligations, best practices, operational goals, and budgets. With expertise in power system engineering, planning and operations, TRC supports public utilities and private energy providers in their efforts to stay ahead of the curve and to meet or exceed regulatory requirements as they evolve.

This regulatory update is provided as a service to TRC’s utility clients, helping to keep you informed of forward-looking issues that will impact your company’s electric system reliability risks along with related topics regarding regulatory developments to help you achieve your company’s business goals.