Utility AES Indiana and software provider Camus said in a study that the utility can best reduce costs by preparing now to launch managed EV charging by early 2029, when it projects 5% of its customers will have installed EV chargers.
Electrification of transportation provides a larger market for renewably-generated electricity, and also presents new problems to be solved.
Charging many electric vehicles at the same time can “result in new system peaks and stress to existing infrastructure,” said a study by utility AES Indiana and software provider Camus. New system peaks may require additional generating capacity, while added thermal stress to existing distribution transformers can reduce their lifespan, at a time when an estimated half of these transformers are already nearing the end of their useful life.
One solution is managed EV charging, which can manage system peaks by shifting load to non-peak periods, and can also manage thermal load on distribution transformers by leveling the load on individual distribution feeders.
Another solution is a forthcoming flexible demand appliance standard for EV chargers, which the California Energy Commission is developing, matched with a system to send continuous price signals to customers. California requires large utilities and community choice aggregators to offer dynamic hourly rates to all customers by year-end 2027. Researchers in California have proposed that a mechanism be defined for customers to have a choice between price signals and managed optimization, separately for each flexible device.
Of those solutions, AES Indiana is pursuing managed EV charging for its more than 500,000 customers in the Indianapolis area.
AES Indiana teamed with Camus, a grid visibility and orchestration software provider, to conduct a study that first projected the timeframe of EV adoption in its service territory. The study projects that by 2029, 5% of AES Indiana customers system-wide will have installed EV chargers, with the percentage being higher on some distribution feeders and lower on others.
To select an appropriate timeframe for launching managed EV charging, Camus projected the annual net benefits of managed EV charging. Camus quantified the peak load reductions possible by shifting the start times for EV charging to off-peak hours, thus avoiding the need for added generating capacity. Camus also quantified feeder-level load reductions from curtailing charging for enrolled participants for up to 20 hours per year, so that the thermal limits of distribution transformers would not be exceeded, with a subset of participants opting out of each event. Those load reductions would enable deferral of distribution transformer replacement, yielding cost savings based on the time value of money.
The study said its approach, by considering the savings possible by managing both the system peak and distribution transformer replacement, “differs from many common managed charging approaches” that are “focused solely on system peak management.”
Annual benefits of managed EV charging exceed annual costs once 5% of customers have EV chargers, the study found, with increasing net benefits in subsequent years.
An EV charging management strategy based on time-of-use pricing was also evaluated. The study found that a time-of-use approach “inadvertently creates new peaks on local equipment, especially later in the analysis with higher levels of EV adoption.” Those new peaks “drive increased capital expenditure compared to no EV management.”
Saying that “engaging EV drivers is an essential component of unlocking EV charging flexibility,” the study reported that “motor, incubated by AES, partners with auto dealerships in the utility’s service area to reach customers,” providing a service included with their EV vehicle purchase.
The study concluded that for AES Indiana, investing in EV visibility and grid-optimized managed charging starting in 2025, with EV programs scaled and active by the time the 5% “tipping point” is reached in the early 2029, yields “the optimal outcome.”
The study by AES Indiana and Camus is titled “The electric vehicle (EV) tipping point: preparing for the future of grid flexibility as EV adoption builds.”
