Vehicle-to-Home Charging Can Cut Costs and Greenhouse Gas Emissions across the US

Electric vehicle (EV) adoption can reduce greenhouse gas (GHG) emissions, but widespread adoption is held back by higher upfront, and–in some cases–lifetime, ownership costs. Here, we consider the possibility that homeowners can use EV batteries to perform an arbitrage that offsets the cost of EV ownership. For a representative EV in the contiguous United States, we estimate the impact of charging strategies on vehicle lifetime GHG emissions and on owners’ electricity bills for charging and other household uses. We account for local climate, regional differences in vehicle use, and projected grid decarbonization during the EV’s lifetime. Compared to uncontrolled charging, optimizing charging and using EV batteries to optimally shift electricity purchases for other household loads (V2H) could reduce emissions from non-EV loads by more than EV charging increases emissions. V2H could cut costs by $3900 ($2500-$6000) or 61% (40%-94%), and emissions by 62tCO2e (39tCO2e-83tCO2e) or 210% (120%-320%).