Dynamic Line Rating (DLR) analysis showed an average 9.9% increase in available transmission capacity, representing an estimated $57.3 million in potential congestion cost savings.
August 2026 Key Findings
- Total PJM congestion costs: $444.1 million
- Average available capacity increase with DLR: +9.9%
- Estimated DLR-enabled savings: $57.3 million
The results highlight an important characteristic of transmission congestion: costs are concentrated around a relatively small number of constraints, while additional capacity may be available on the same infrastructure under actual operating conditions.
Case Study: Graceton–Manor 230 kV
The Graceton–Manor 230 kV constraint was again among the most significant monitored transmission bottlenecks during August.
Over the month, Gridraven identified:
- Congestion costs: $17.46 million
- Average available capacity increase with DLR: +8.2%
- Estimated DLR-enabled savings: $7.16 million
Gridraven’s analysis therefore indicates that improved utilization of the existing transmission line could potentially have reduced congestion costs by approximately 41% during the period.
The line-capacity analysis shows that available DLR capacity frequently exceeded the PJM base rating throughout August. This indicates that real operating conditions periodically provided additional thermal headroom that conventional ratings did not fully reflect.
Why This Matters
Transmission congestion occurs when lower-cost electricity cannot move across the grid because of constraints on individual transmission elements. Grid operators must then rely on more expensive generation, increasing electricity costs.
Dynamic Line Ratings do not eliminate the need for new transmission infrastructure. However, they can help operators make better use of infrastructure that is already in place.
August’s results show that even an average increase of around 10% in available capacity can have a meaningful economic impact when applied to heavily congested parts of the network.
With congestion continuing to impose hundreds of millions of dollars in monthly costs across PJM, building new transmission and using existing transmission more efficiently need to happen in parallel.
