For us electricity is $0.15/kwh. Even without our roof solar it is cheaper to drive in EV mode than gas. Gas would have to be under $2.00/gallon for gas to be cheaper. Currently gas is about $2.95/gallon. If we put the solar into the mix of course driving in EV wins big time. We are not subject to TOU but if we were I'd have to look into buying a battery for the solar system to improve our costs and time shift our usage. In general though I don't think batteries are cost effective. I would start using the charge schedule to charge at the lowest rates.