Active management can reduce on-peak EV charging by 59–93% compared to unmanaged charging, significantly mitigating grid congestion and improving load diversity.
That is the finding of a study conducted by global consultancy Brattle on behalf of EnergyHub, the result of a trial conducted in Washington State using EnergyHub’s EV managed charging solution.
The report, titled ‘Demonstrating the Full Value of Managed Electric Vehicle Charging’, sets out how managed charging strategies can provide value for EV drivers and avoid distribution system upgrades.
Increased electrification in the move away from fossil fuels is putting an increasing strain on electricity grids globally, as the infrastructure struggles with the additional load. While infrastructure upgrades will be an inevitable (and expensive) part of the energy transition, there are solutions to get around the constraint.
By increasing hosting capacity and deferring capital expenditures, active managed charging offers a scalable solution to accommodate growing EV adoption without overburdening existing infrastructure.
The study highlights that both active and passive managed charging strategies can reduce system costs, defer infrastructure upgrades, and improve customer satisfaction.
Active vs. passive managed charging: Key differences
The trial evaluated two distinct approaches to managed charging:
Active managed charging: This strategy uses telematics and control algorithms to optimize EV charging, minimizing costs for both customers and the electric system. Customers retain the ability to override curtailment signals when necessary.
Passive managed charging: Relies on price signals, such as time-of-use (TOU) rates, to encourage off-peak charging.
Observed performance: Shifting load and reducing peaks
According to the report, while effective in shifting load, passive strategies lack the precision of active management in optimising grid performance.
Active managed charging increases the hosting capacity of distribution grid assets by 1.3x to 3.2x, enabling utilities to defer upgrades by up to 10 years. This reduces distribution grid costs by about US$200 per EV annually, with potential savings reaching US$400 per EV per year.
The trial demonstrated the effectiveness of managed charging in shifting EV load out of high-cost periods and reducing peak demand.
‘Active management smooths EV load at the service transformer and feeder levels, reducing distribution grid congestion,’ the report notes.
Enhancing customer experience
Consumer engagement is a key element in managed charging, and a metric that is arguably hard to predict on a wide scale. However, the Brattle trial recorded an opt-out rate of just 3%. The report puts this down to EnergyHub’s solution, which prioritises customer convenience, balancing optimisation with driver satisfaction.
The report states that ‘100% of EVs that plugged in with sufficient time to charge reached their desired target state of charge by the end of the optimisation window’.
A similar trial that is ongoing in the UK, run by home charging solutions provider Ohme, also noted ‘very low’ dropout rates.
Business implications: Cost savings and infrastructure deferral
By deferring the need for infrastructure upgrades, the report found that active managed charging offers cost savings for utilities, relative to unmanaged charging or passing time-of-use strategies.
As EV adoption accelerates, utilities face mounting pressure to adapt their infrastructure to meet rising demand. Managed charging strategies provide a cost-effective pathway to address these challenges.
The report suggests that leveraging active management solutions will be key to balancing grid performance, cost efficiency, and customer experience; flexibility more generally, through demand and energy storage, is well-known to be a key part of the energy transition. With the potential to defer infrastructure upgrades by up to a decade and deliver significant cost savings, managed charging represents a critical opportunity for industry leaders to future-proof their operations in the face of rapid electrification.
