Ahead of the Curve

The US electricity distribution grid is at a critical inflection point. Widespread electrification — especially of transportation — is creating a surge in demand that is arriving quickly and unevenly. In key locations, such as warehouse districts, highway corridors, and dense urban zones, electric vehicle (EV) charging is poised to use a significant share of available grid capacity. Current connection speeds may delay activation of chargers, impeding access to clean mobility and potentially leading to further increases in costs for customers. RMI’s new report, Ahead of the Curve: Utility Planning for an Electrified Transportation Future, examines how proactive planning and investments in distribution system upgrades can enable utilities to stay ahead of demand while promoting economical and reliable access to clean mobility.

Through detailed analysis using utility data and RMI’s GridUp EV load forecasting tool, the report explores when and where grid upgrades are most likely to be needed to accommodate load growth. Additionally, the study uses RMI’s Optimus modeling tool to compare the costs and rate impacts of traditional “just-in-time” distribution grid upgrades with more proactive investments. The findings indicate that proactive investment often results in long-term cost savings, improved grid reliability, and a reduced risk of interconnection bottlenecks — especially when combined with managed charging strategies. This report highlights:

• Where and when EV loads may exceed feeder and substation headroom for case study utilities across New York, Minnesota, and Massachusetts.
• How managed charging can reduce distribution capacity needs by up to 30 percent.
• How ratepayer impacts of traditional vs. proactive investment approaches compare across multiple EV adoption and charging scenarios for an illustrative utility.
• Actionable recommendations for utilities, regulators, consumer advocates, and state agencies.

Importantly, this report emphasizes that ratepayer savings from proactive investment approaches may be amplified under the right conditions: when EV adoption rates are strong, load management strategies are in place, and larger, one-time grid upgrades can capture economies of scale. This analysis provides readers with a foundation to identify where and when forward-looking investments are advantageous and may help support an affordable, reliable, and electrified transportation future.

Executive Summary