EV batteries can act as utility power batteries. If lots of EVs do this, they can represent a size-able battery bank.
Last year, the 350 cars plugged into Kaluza’s V2G platform collectively with OVO, Energy Ltd., one of the country’s largest utilities, fed .891 gigawatt hours of electricity back to their adjacent homes and to the grid; that’s enough to power about 287 British homes for a year. The average participant made roughly $500 over the course of the year before paying the standard electric bill. Kershaw, who charges his car via a solar array on his roof before feeding the same power back to the grid, pays essentially nothing for electricity these days.
Source: How EVs with Bidirectional Charging Can Offset High Energy Costs – Bloomberg
Other research suggests that using just 10% of EV battery capacity will not harm overall battery life – and leaves most of an EV’s capacity still available for driving (without recharging).
If EV owners are paid by the utilities, and if, as above, they have solar PV generation, some “consumers” may become profitable producers, literally turning the electric utility model inside out.
My house is powered with solar PV and exports power during the day but draws from the utility at night. We pay a $10/month fee to use the utility’s power grid as our battery, but otherwise we are “net zero” in our exchange of power with the utility. Using EVs as a battery storage might eliminate the need for us using the “grid battery”. However, do to local regulations, we are required to remain connected to the utility.