Two Years In, Stakeholders Discuss Progress and Challenges with FERC Order 881 Compliance

Co-authored by Lisa Deppa and Rob Schaerer

 

On May 7th, POWER Engineers led a panel of industry experts at the IEEE Power & Energy Society Transmission and Distribution Conference & Exposition to discuss progress toward the fast-approaching deadline for FERC Order 881. With representation from a utility, a regional transmission organization, a conductor manufacturer and an engineering consultant, the panel provided unique perspectives from across the power delivery industry.

 

What is FERC Order 881?

FERC Order 881 requires utility transmission owners to implement ambient adjusted ratings (AAR) on their transmission lines and applicable equipment by July 2025. This massive undertaking aims to improve the accuracy and transparency of transmission line ratings. If successful, the order will reduce artificial transmission congestion, ultimately making room for more power capacity on the grid.

 

Progress and Challenges

The industry has made progress toward complying with FERC Order 881 since this journey began two years ago. The panelists shared some of what they’ve learned. While Order 881 emphasizes the effects of ambient temperatures and solar radiation, other aspects of the line rating methodology were left open-ended. Adjustments to unaddressed parameters are currently being handled case-by-case, and in some instances can cause the rating to drop.

For example, Deborah Fradelis of San Diego Gas & Electric noted that the utility plans to adjust their emissivity value based on more recent data. They feel the previous values were too high and are now obsolete and unconservative. With her role in operations, she said the possibility of ambient-adjusted line ratings that fall below the static ratings keeps her awake at night.

Regional transmission organizations and independent system operators are also stepping in to provide some guidance on these rating methodology gaps, but they can only do so much. Will Holden of Southwest Power Pool cited several references his team has given to members, including some direction on sunrise and sunset times as well as ambient temperature buffers. However, utilities are still ultimately responsible for their own methodologies and will likely have to tackle some of the harder aspects, like wind speed, alone.

 

What About the Wind?

Although wind is not the primary focus of ambient-adjusted ratings, it was still a topic of interest at the panel.

Joe Coffey of Prysmian mentioned hearing the word “philosophy” from others as they discussed line rating methodologies, which seemed contrary to the idea of “accuracy,” which appears many times in Order 881. However, Order 881 addresses the topic of accuracy only for ambient temperature and solar radiation, leaving out many other parts of the methodology such as wind.

It was noted that data is ultimately needed to identify a suitable wind speed. Publicly available data may not always reflect the conditions at a transmission line since that data is typically measured at airports. More accurate data can be obtained by placing some type of weather station along the line, or by using dynamic line rating (DLR) sensors. While Order 881 does not require utilities to adjust for wind speed, it is prudent to consider this variable especially when applying new transparency requirements.

 

The Clock is Ticking

July 2025 is approaching rapidly. The panel audience showed a lot of curiosity and concern about whether the industry would be able to meet the tight deadline. Some referenced the three-year extension granted to the New York Independent System Operator (NYISO) and wondered if it would set a precedent for more extensions. Holden explained how the NYISO extension primarily accounted for energy management system (EMS) upgrades already underway, which delayed NYISO’s ability to move forward on the EMS upgrades needed for Order 881. The extension granted to NYISO is expected to impact member utilities, limiting their ability to use AAR by the deadline. The panel did not expect wide-spread extensions but did note that the timeframe is absolutely a challenge for many. Transmission owners may need to prioritize which components of Order 881 they can realistically meet by the deadline.

 

Looking Ahead

The audience was quite curious about whether DLR might be required in the future and when the industry might start seeing such requirements. While no wide-spread requirement to use DLR has been issued yet, the operational framework being formed with Order 881 would enable this possibility. Consensus was that FERC will likely be pushing DLR in some capacity in the future.

 

Article originally published on the POWER Engineers website.