FERC has approved three reliability standards setting model validation and data sharing requirements for inverter-based resources, fulfilling the second tranche set in the commission’s Order 901 from October 2023.

Commissioners approved the standard at their monthly open meeting Feb. 19 (RD26-1 et al.), with Chair Laura Swett calling the task of ensuring IBR performance “more important than ever.”

FERC’s acceptance of the standards leaves one more set of standards to satisfy Order 901, covering operational and planning studies, due Nov. 4. NERC’s Standards Committee assigned development of those standards to separate drafting teams in August 2025. (See NERC Standards Committee Tackles Final Order 901 Tranche.)

NERC submitted the second set of IBR requirements to the commission in November 2025, comprising five standards:

• • MOD-032-2 (Data for power system modeling and analysis)
  • IRO-010-6 (Reliability coordinator data and information specification and collection)
  • TOP-003-8 (Transmission operator and balancing authority data and information specification and collection)
  • MOD-026-2 (Verification and validation of dynamic models and data)
  • MOD-033-3 (Steady-state and dynamic system model validation)

MOD-032-2 will require planning coordinators and transmission planners to specify the data needed to model IBRs for planning purposes and identify entities responsible for providing the data, along with requiring similar data on aggregated distributed energy resources. IRO-010-6 and TOP-003-8 will “reinforce” requirements for reliability coordinators, transmission operators and balancing authorities to request IBR-specific data and parameters in their data specifications.

MOD-026-2 requires generator owners and transmission owners to perform model validation and model verification of positive sequence dynamic and electromagnetic transient models provided to their TPs. MOD-033-3 includes requirements for PCs to have a documented process for validating models applying to their portions of the electric system, which must include performance comparison between actual system behavior and the steady-state and dynamic models of the system.

In its order, FERC acknowledged that ERCOT, ISO-NE, MISO, NYISO, PJM and SPP had submitted comments supporting MOD-026-2 but disagreeing with a provision that excluded “generator owners or transmission owners of legacy facilities with no original equipment manufacturer support for EMT models from the requirement to provide EMT models to their transmission planners.”

The RTOs wrote that NERC’s definition of legacy facilities — covering any facility with a commercial operation date earlier than the effective date of MOD-026-2 — includes IBRs that are currently going through the interconnection process, along with those already in service. They claimed the exclusion would unfairly shift the burden of obtaining EMT models from GOs and TOs to transmission planners, despite their lack of knowledge and access to the facilities, and requested that the relevant language be removed from the standard.

NERC replied in the same docket that the team behind the standard “adopted a limited and narrowly tailored exclusion” for legacy facilities after concluding that requiring owners of such facilities to develop their own models would require “costly [and] extensive testing” that would stress the facilities, potentially creating reliability risks. The ERO also observed that the exclusion would apply only in cases where the OEM no longer supports the equipment; NERC predicted that the number of such cases would fall as new resources were brought online.

Commissioners declined the RTOs’ request to remove the exclusion language, stating that they were “persuaded by NERC that the impact of the exclusion will be limited.” FERC approved all the proposed standards “as just, reasonable, not unduly discriminatory or preferential … in the public interest [and] responsive to the relevant directives in Order 901.”