Negative Electric Vehicle Emissions: Vehicle-to-Grid Can Incentivize Enough Wind and Solar Investment to Reverse EV Charging Emissions.

Abstract

Consequential emission analyses of power system interventions typically overlook induced structural changes. We estimate the consequential power system emission effects of plug-in electric vehicle (PEV) charging due to both operational effects and induced renewable capacity investments. We study PJM, the largest U.S. grid operator, with a grid mix representative of North America, assuming 10% fleet electrification. We find that charging immediately after each day's final trip increases grid emission externalities and provides little incentive to increase renewable infrastructure investment. In contrast, flexible cost-minimizing charging creates economic incentives to increase wind and solar capacity investment by 4% for unidirectional charging or by 23% for bidirectional vehicle-to-grid (V2G). This induced investment reverses emission consequences of PEV charging: estimates ignoring capacity changes find PEVs increase grid emission externalities by $240-$610 per PEV-year, whereas estimates accounting for induced renewable investments find that adding PEV load can reduce total grid emission externalities by $230 per PEV-year with flexible charging and by $2200 per PEV-year with V2G. Overall, results suggest that leveraging flexibility in charge timing and V2G to reduce power system costs can also produce substantial emission cobenefits.