The FERC voted on December 16th to approve a final rule that will utilize the nation’s transmission grid with increased efficacy and reliability while decreasing consumer cost by enhancing the accuracy and transparency of transmission line ratings.
The maximum transfer capability of transmission lines is represented by transmission line ratings and can shift based on weather conditions. Under the final rule, all transmission providers (both inside and outside of organized markets) must use ambient-adjusted ratings as the baseline for assessing near-term transmission service to increase the accuracy of near-term line ratings. Line ratings are generally founded on conservative suppositions about worst case, long-term air temperature and other climatic conditions that may result in the underuse of the transmission grid.
The final rule does not require the adoption of dynamic line ratings that allow for other factors, including wind speed. However, the rule does mandate that organized market operators develop and maintain systems and processes necessary to allow transmission owners desiring to use dynamic line ratings the ability to do so.
The adopted rule also:
- recognizes that dynamic line ratings may provide incremental benefits
- announces that the FERC is opening a proceeding in AD22-5-000 to continue building the record and investigate the potential for further action on dynamic line ratings
Transmission providers are required to submit compliance filings within 120 days of this rule’s effective date. The requirements in this rule must be applied no more than three years from the compliance filing due date.
For more information, contact Mary O’Driscoll, Director, Media Relations at (202) 502-8680 or mediadl@ferc.gov.
Sources:
FERC Rule to Improve Transmission Line Ratings Will Help Lower Transmission Costs (ferc.gov)
Item E-1 - Managing Transmission Line Ratings (ferc.gov)