What is FERC Order 881?
The Federal Energy Regulatory Commission (FERC) issued Order 881 on December 16, 2021, about using of ambient-adjusted line rating (AAR), and it was reviewed on May 19, 2022. FERC 881-A requires the transmission providers to use ambient-adjusted thermal ratings on their power lines to increase transmission capacity by achieving a more accurate near-term line rating. This order must be fulfilled by 2025. Moreover, FERC 881-A also requires the maintenance of an accessible and protected database about the transmission line ratings and methodologies by the utilities. The order aims to enhance the accuracy and transparency of transmission line ratings, considering favorable ambient conditions.