March 18, 2023
With commercial electric vehicles (EVs) gaining acceptance for their ability to transport goods with high efficiency and zero emissions, another big benefit has yet to be fully embraced: their ability to serve as a fleet of rolling energy storage devices. As more electric vehicles and charging systems with bi-directional energy capabilities are built, the advantages of using vehicle-to-everything (V2X) connections are becoming more obvious. Commercial fleet owners could use these EVs in several different ways, ranging from a backup power source to charging another EV, to participating in the energy trading market and generating revenue by selling electricity back to the grid.
For commercial fleets, especially vehicles like delivery or shuttle vans that may be idle for most of the time, this feature can save additional money or generate revenue. By charging during off-peak hours and feeding electricity back into the grid (or building) during costly time-of-day peak electricity rates, commercial fleets can not only mitigate their own electricity bills but also potentially even make money.
With the right charging system, electric vehicle fleet owners can draw power from one vehicle to charge another (vehicle-to-vehicle) without having to pull electrons from the grid, potentially saving money and possibly time. By transferring lower-cost, off-peak electricity from one vehicle to another during peak rate times, fleets could see lower charging costs for their vehicles and more efficient processes for keeping them topped off. However, because EVs can’t be directly connected from battery to battery, there are inefficiencies due to the necessary conversion of DC to AC and then back to DC which is something that the design of future charging systems will hopefully address.
Taking this feature one step further, with the use of bi-directional EV chargers and an advanced charging management system, fleets would have the opportunity to utilize the excess battery storage in their EVs to sell electricity back to the electric utility (V2G: Vehicle-to-Grid) during periods when the pricing is right, essentially turning their batteries-on-wheels into a revenue source. However, as with previous examples in this article, there are some limiting factors currently in place, namely the need for bi-directional charging equipment, the inherent power losses in stepping voltages up for the grid, and the need for the local utility to allow net metering. But as EVs and EV charging technology continue to improve, some of these limiting factors may soon be overcome.