A study of Southern California Edison (SCE) customers finds that electric vehicle (EV) batteries used as a “virtual power plant” can shift the entire residential peak load to nighttime hours by using energy stored in batteries during the day and managing charging at night with EV market penetration of only 10 percent. Moreover, annual net savings were $560/EV customer.
Smoothing the utility’s load reduces all customers’ costs because peaks require additional power plants to be dispatched; when plants are dispatched only during peaks, the annual cost must be covered during a relatively small number of hours, which results in higher electricity prices for everyone.
The finding that a small EV market share can completely clip the residential peak (see charts below) and save participants $560/year even after paying for overnight charging has long been suspected but the study, by Jerry Jackson, provides highly credible evidence.
This important discovery highlights savings that help offset today’s higher EV sticker price. Meanwhile, for non-EV customers, lowering the system peak reduces the cost of electricity and supports the case for utilities investing in EV charging infrastructure.