The Evolution of Managed EV Charging

One of the big questions around the transition to electrified ground transportation is whether utilities actually have the wherewithal to supply the electricity required to energize hundreds of millions of vehicles. The consensus is that there is more than enough generating capacity nationally, but the distribution system remains suspect. To that end, utilities would love to use the generating capacity they have and earn revenue but also manage when and where the charging happens. 

As with many things, demand for electricity is not constant throughout the day and certainly not over multiple seasons. Gasoline demand is also not constant. But unlike gasoline, which can be produced at a relatively constant rate and stored in tanks to be dispensed as needed, electrons are more challenging. The problem is exacerbated by the shift to renewables, which adds another major variable to the generating puzzle. In a recent conversation with Sarah Nielsen, executive director of EV programs at Michigan-based utility Consumers Energy, explained that “the problem is getting the electrons where they need to be, when they are needed.”

Since the launch of the modern EV era a decade ago, utilities have been trying out a range of solutions to manage EV charging to mitigate the stress on the grid while giving drivers the best possible experience. One of the first solutions was smart connected chargers that could be remotely controlled by the utility to turn them on when off-peak rates (and demand) kicked in. However, as the number of EVs grows, the system gets more complex, because suddenly initiating charging sessions for thousands to millions of EVs precisely at the off-peak hour could create even more stress. So charging sessions must be intelligently staggered.  

Consumers Energy, like many utilities, has had rebate programs for smart chargers, but they are shifting focus to subsidizing the installation of 240 V outlets and purchase of more basic chargers. In turn, they are examining how to integrate with the connectivity and software systems built into vehicles like General Motors upcoming Ultifi platform. Such integration would enable Consumers Energy to communicate with the vehicle to manage charging rather than with the charger. 

Beyond managing when chargers are enabled, utilities are testing more sophisticated demand response solutions. In addition to stopping charging to relieve the load on the grid, PG&E in California is testing a system using EVs from Ford and GM that takes homes entirely off the grid for a time to help avoid rolling blackouts. 

Automakers are beginning to incorporate bidirectional charging capabilities and the Ford F-150 Lightning includes intelligent backup power. This system utilizes a bidirectional charger and home integration kit from Sunrun that automatically detects a power outage. When detected, the integration unit flips a transfer switch to disconnect the home from the grid and starts drawing power from the truck until power is restored. 

This Sunrun system is controlled locally, but there are potential benefits to centralized forms of control from the utility. For example, PG&E is testing a version that it can proactively trigger before the grid reaches a critical stage. By temporarily disconnecting homes, utilities are aiming to leverage the growth of the connected EV population to balance the demand for electricity with the ability to distribute power as they work to deploy upgrades to that distribution system in the coming years. Big investments will be required across the transportation and electricity ecosystem, but if implemented as part of a holistic approach, it should ultimately benefit customers and utilities with a more resilient grid, better utilization of generation resources, and lower operating costs for drivers.