Congestion Monitoring System

THE CHALLENGE

Given the influx of connecting new renewable generation in recent years, ITC Midwest’s system has experienced additional challenges and congestion.
ITC conducted a comprehensive review of congestion issues within the ITC Midwest system. The focus was to understand the impact on customer costs and evaluate how transmission build-out contributes to reducing generator fuel costs.

Recently there has been a resurgence of congestion on the Midwest system, surpassing a previous high in 2012. Between 2020 and 2022, congestion costs for ITC Midwest surged from approximately $56 million to over $178 million*, primarily driven by the accelerated addition of new generation outpacing corresponding transmission infrastructure. The increase in wind generation capacity in Iowa, coupled with minimal additions to 345 kV transmission lines, contributed to this surge in congestion.

*ITC’s congestion cost estimate reflects unhedged congestion from an overall marketplace perspective, serving as a benchmark to illustrate relative congestion impacts on prices.

THE SOLUTION

In response to these challenges, ITC implemented the Market Analysis and Congestion Evaluation (MACE) program in 2013, to mitigate the impacts of transmission system constraints.

The MACE program focuses on analyzing real-time and historical data, considering factors such as line outages, generator configurations and renewable energy operations. By calculating shadow prices and examining Local Marginal Prices (LMPs), ITC gains insights into congestion effects and price impacts. Initiative-taking measures include engagement with MISO, reconfiguring lines and opening lines on lower voltages to mitigate congestion in real time.

Since its start, the program has generated over $600 million in current and future cost savings for customers, with the Midwest service area experiencing the most significant impact due to grid interconnectedness and an influx of new generation.