The Dollars - and Sense - of EV Smart Charging

Silver Spring’s analysis indicates that utility ownership of smart grid EVSE has the highest costs but yields the greatest benefits. In cases where the utility owns or subsidizes the EVSE, the utility has peak load control and therefore can avoid increases in peak demand and the associated costs of added generation, transmission and distribution capacity. But in the scenario where the utility owns the EVSE, it is assumed the utility also can perform load scheduling during off-peak times to shift EV charging in real time to balance energy supply and demand. This flexibility enables utilities to integrate more intermittent renewable sources, reduce grid reliability risks and charge EVs at times when the cost to procure energy is lowest. All of these benefits can be achieved while providing for consumer convenience in EV charging.

Clearly, the cost to the utility is lower when customers pay for the smart grid EVSE hardware and installation, even if the utility pays a partial subsidy. However, customer ownership of EVSE creates risks with regard to billing and/or metering accuracy. If the utility opts to install its own EVSE-specific meter to mitigate the risks, the utility gains more control but its costs nearly double, offsetting a large portion of benefits. And if utilities treat EVs like an appliance, they lose the ability to do smart charging and are likely to incur costs for adding generation, transmission and distribution capacity and procuring additional energy at peak times to service EV charging.