PJM Interconnection has become the first Regional Transmission Organization (RTO) to fully implement ambient-adjusted ratings (AAR) for transmission lines, complying with FERC Order 881. This transition enables PJM to maximize the usable capacity of its existing grid infrastructure by incorporating real-time weather data into transmission line ratings.
Key innovations include:
- Dynamic Ratings
- Capacity Optimization
- System-Wide Integration
FERC Order 881, issued in 2021, mandated that transmission operators adopt AARs to enhance grid efficiency by accounting for weather impacts on line capacity. By leveraging granular thermal limits, PJM can now safely transmit more power, reduce operational costs, and ease transmission constraints without requiring new infrastructure.