NERC’s PRC-029-2 became mandatory and enforceable on October 1, 2026. (NERC One Stop Shop workbook) It sets frequency and voltage ride-through requirements for inverter-based resources, such as solar, wind and battery storage plants. (NERC PRC-029-2) (Federal Register, Order No. 909) It applies to generator owners. It does not cover loads such as data centers. (NERC PRC-029-2)
Correction
This article previously said PRC-029-1 took effect on October 1. That was wrong. FERC approved PRC-029-1 in Order No. 909, issued July 24, 2025. (Federal Register, Order No. 909) NERC’s Board of Trustees adopted the revised PRC-029-2 on August 18, 2026, under Project 2025-05. (NERC One Stop Shop workbook) FERC approved PRC-029-2 by a letter order issued September 30, 2026, in Docket RD26-10-000. (FERC eLibrary, accession 20260930-3090) NERC lists PRC-029-1 as inactive from September 30, 2026. (NERC One Stop Shop workbook) It was retired the day before its own United States effective date of October 1, 2026. (NERC PRC-029-2 implementation plan)
What the standard asks of a plant
Each generator owner must make sure that the design and operation of each inverter-based resource meet the ride-through requirements. (NERC PRC-029-2) In the continuous operation region, a plant keeps delivering real power at its pre-disturbance or available level, whichever is less, and keeps delivering reactive power. In the mandatory operation region, it exchanges current up to its maximum capability to support voltage. It may block current only in the permissive operation region, and only if that is necessary to avoid tripping. (NERC PRC-029-2)
FERC approved PRC-029-1 because its ride-through requirements mitigate inverter tripping and momentary cessation. (Federal Register, Order No. 909) PJM says the grid now faces ride-through problems on the load side as well. (PJM Inside Lines, August 11, 2026)
What the phasing says
The PRC-029-2 implementation plan carries forward the phased dates of PRC-029-1 for requirements R1 to R3 without change. (NERC PRC-029-2 implementation plan)
- Owners of bulk electric system plants comply with the design parts of R1 to R3 by the effective date of PRC-029-1, which the standard sets at October 1, 2026 in the United States.
- Non-BES plants with an aggregate nameplate capacity of 20 MVA or more, connected at 60 kV or above, comply with the design parts from January 1, 2027 or that effective date, whichever is later.
- The operating parts of R1 to R3 wait until the owner has the disturbance monitoring that the PRC-028-1 implementation plan requires.
(NERC PRC-029-2 implementation plan) (NERC PRC-029-2)
Requirement R4 allows a documented exemption for a plant with known hardware limitations that prevent it from meeting the ride-through criteria. (NERC PRC-029-2) An owner whose plant was in service and subject to compliance by October 1, 2026 submits that documentation within 12 months of that date. (NERC PRC-029-2 implementation plan)
Loads have their own rules
A data center is a load, so PRC-029-2 does not apply to it. Computational loads are not subject to NERC Reliability Standards today. (PJM Inside Lines, August 11, 2026) In Texas, ERCOT’s NOGRR282 took effect August 1, 2026, after the Public Utility Commission approved it on July 9. (ERCOT NOGRR282)
Paragraph 7 of its voltage section targets sag counting. A large computational load may not use a trip or transfer scheme that acts solely on a number of voltage sags or swells within a period of time, where the rule requires the load to ride through each one. If equipment limits force such a scheme, the load must be able to stay connected through at least six sags or swells within 90 seconds. (ERCOT NOGRR282, PUCT report)
If ERCOT finds that a load failed to ride through, the customer that represents the load must report the root cause within 90 days of ERCOT’s request. (ERCOT NOGRR282, PUCT report)
National computational load standards
FERC ordered NERC on July 16, 2026 to file computational load standards by December 31, 2026. (FERC order, Docket RD26-7-000) NERC’s final ballot closed October 14, and its Board of Trustees adopted the standards on October 26. NERC will now file them with FERC. (NERC newsroom, October 27, 2026)
That first phase will not set minimum voltage or frequency ride-through for computational loads. PJM reports that those requirements are expected in NERC standards in 2027. (PJM Inside Lines, August 11, 2026)
Read the full explanation of the standards in NERC computational load standards explained. The FERC order is covered in FERC and data centers: compliance.
Where this stands
PRC-029-2 is in force for inverter-based generation. NOGRR282 is in force in Texas for large computational loads. The national load standards are adopted by NERC’s Board and wait for filing at FERC. A panel-level controller is not a compliance product and does not provide ride-through. (3DFS Standards Compliance) The first step for any site is one week of measurement at the site. (3DFS Resilience)
Critical perspective
PRC-029-2 names one functional entity, the Generator Owner, and its facility list holds inverter-based resources alone (NERC PRC-029-2). A data center is outside it by design. Its numbers travel anyway. PJM’s draft frequency table for large computational loads matches the PRC-029-2 bands, and neither PJM deck cites the standard (PJM Planning Committee, October 6, 2026, NERC PRC-029-2, Attachment 2). Both require 299 seconds between 61.2 and 61.8 Hz and between 57.0 and 58.8 Hz, counted over 10 minutes (PJM, NERC PRC-029-2).
The generator path was slow. FERC directed the work in Order No. 901 of 2023 and approved PRC-029-1 in 2025 (Federal Register, Order No. 909). Design compliance for bulk system plants began October 1, 2026 (NERC PRC-029-2 implementation plan).
Even then, Requirement R4 lets the owner of a plant in service, or under contract, before PRC-029-1 took effect document a hardware limit and take an exemption (NERC PRC-029-2). Loads start that path with first standards that set no minimum ride-through (NERC FAQ).
The two sides also interact. Eastern Interconnection frequency reached 60.092 Hz during the July 22 load transfer (PJM, October 6, 2026). Draft NERC working group recommendations that PJM presented ask whether the high-frequency duration needs adjustment “so that generation and load do not disconnect simultaneously” (PJM). PRC-029-2 cannot settle that question. It governs one side of the meter.
Engineers should read PRC-029-2 as the probable template for load requirements, not as a rule that covers them. A site designed to its frequency table today would meet the frequency table in PJM’s draft as written (PJM).
Frequently asked questions
Did PRC-029-1 take effect? No. NERC lists it as inactive from September 30, 2026. PRC-029-2 replaced it the next day. (NERC One Stop Shop workbook)
Does PRC-029-2 apply to data centers? No. It applies to generator owners of inverter-based resources. Data centers are loads, covered by ERCOT’s NOGRR282 in Texas and by the NERC standards still to be filed at FERC. (NERC PRC-029-2) (NERC newsroom, October 27, 2026)
When will national ride-through limits for data centers exist? Not in the first phase. PJM reports that minimum voltage and frequency ride-through requirements are expected in NERC standards in 2027. (PJM Inside Lines, August 11, 2026)
