Active Managed EV Charging Can Double EV Hosting Capacity

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Electric vehicles are ‘batteries on wheels’ and have capabilities beyond transportation. Because of the recent frigid weather and snow, someone mentioned the fact that a Ford Lightning can be used as backup power during an outage. Of course, it isn’t only Lightnings that can provide such backup power. Potentially, any EV can be used as a backup power supply for a while. What EVs can do goes far beyond what one or two can do for backing up residential power for homeowners. 

Zach just wrote an article about the collective potential of EVs where many can be used at the same time — as in hundreds, thousands, or tens of thousands — to function as a virtual power plant.

Vehicle to grid, vehicle to load, bidirectional charging…these capabilities go far beyond just driving an EV, and well beyond what many gas and diesel vehicles can do. One myth is that when there are more and more EVs, they must burden grids, but that claim overlooks collective EV benefits. 

A new report prepared for Energy Hub notes that “Active Managed EV Charging Can Double the Distribution Grid’s EV Hosting Capacity.“

Freddie Hall, Data Scientist at EnergyHub, and Akhilesh Ramakrishnan, Managing Energy Associate at The Brattle Group, answered some questions about it for CleanTechnica.

What are active managed charging solutions?

Active managed charging refers to control algorithms implemented by distributed energy resource management systems (DERMS) providers that use telematics to optimize charging to reduce customer and  electric system costs.

Flexibility: Unlike static “passive” signals like Time-of-Use (TOU) rates, active management recalculates in real time to account for plug-ins, early departures, and driver overrides (opt-outs).

EnergyHub’s active managed charging solution allows multiple objectives to be combined, enabling utilities to reduce bulk systems costs, avoid distribution constraints, while ensuring drivers receive the charge they need by the time they depart. The Brattle Group evaluated two different variations of EnergyHub’s active managed charging solution referred to in the report as TOU + Load Limits and Wholesale + Load Limits.

TOU + Load Limits – shifted charging off peak based on prices from a time-of-use rate while reducing charging load below a load limit threshold to delay distribution upgrades.

Wholesale + Load Limits – shifted charging to minimize wholesale electricity, transmission and generation capacity costs while reducing charging load below a load limit threshold to delay distribution upgrades.

Load limit structure – this study assigned real vehicles to multiple distribution assets with limits set across from the primary network down to the secondary system where service transformers served 10 homes with 4-5 EVs. EnergyHub refers to this type of optimization as multi-level distribution load optimization as it protects various tiers of the distribution system collectively

How can they cut EV charging peaks by up to 50%?

Active management reduces coincident peaks (multiple EVs charging at once) through load limiting.

Smoothing Demand: It smooths the load at service transformer and feeder levels by determining exactly how many vehicles can charge at once.

Mitigating “Snapback”: Passive TOU rates often cause a “snapback” effect where many cars start charging simultaneously the moment the off-peak window begins. Active management avoids this by staggering charging starts.

Observed Results: In the trial, the aggregate peak load was 55% lower than under a passive TOU strategy (85 kW vs. 190 kW).

What is doubling a distribution system’s hosting capacity and why does it matter?

Hosting capacity is the number of EVs a specific part of the grid (like a feeder or transformer) can support before requiring an expensive physical upgrade.

The Benefit: Active management was shown to increase primary distribution hosting capacity by 1.3x to 2.3x and secondary distribution capacity by 2.2x to 3.2x.

Why it Matters: Doubling or tripling capacity allows utilities to serve more customers with existing infrastructure, delaying rate impacts and providing more flexibility for capital allocation.

How can active management defer distribution upgrades by up to 10 years?

By effectively spreading out the charging load, active management prevents grid assets from reaching their thermal or capacity limits as quickly.

The Mechanism: In a scenario where 25% of annual vehicle sales are EVs, the lower peak loads from EnergyHub’s active managed charging allow planners to keep using existing equipment for a decade longer than they could under a passive TOU strategy.

Specific Examples: For a primary feeder, an upgrade might be needed at 14% EV penetration under passive TOU, but deferred until 31% penetration with active management.

How can active management reduce system costs by up to $400 per EV annually?

The $400 figure represents the high end of the “full value stack” created by active management in regions with high energy price volatility and constrained grid capacity. This avoided system cost is when we compare active managed charging against an unmanaged charging, where vehicles begin charging upon plugging in.

Distribution Savings: It reduces distribution grid costs by up to $180 per EV per year in the long run by deferring capital expenditures.

Bulk System Savings: It avoids $30-$40 in energy costs by shifting load to the cheapest wholesale hours and $20-$130 in generation capacity costs by reducing peak demand.

Transmission Savings: It can save $15-$50 by reducing the need for load-driven transmission upgrades.

How can it shift 95% of charging to off-peak hours?

Active managed charging algorithms are designed to handle complex rate schedules while prioritizing driver needs.

Targeting Windows: The software optimizes the charging schedule to occur almost entirely within the off-peak window defined by the utility when vehicles are able to have their charging shifted.

Performance: The trial demonstrated that active management can deliver 95% of charging off-peak, which can reduce a driver’s EV charging bill by 50% compared to a flat residential rate while ensuring 100% of vehicles that plug-in with sufficient time reach their charging targets before departing.