Green Charging of Electric Vehicles Under a Net-Zero Emissions Policy Transition in California

Research Team: Alan Jenn (lead) and Austin Brown

University: UC Davis

Problem Statement: California has set ambitious goals of putting 5 million zero‐emissions vehicles (ZEVs) on the roads by 2030 and installing 250,000 electric vehicle charging stations by 2025. Increasing electricity loads from electric vehicles (EVs) will require efficient integration with the electric power grid. With high penetration of intermittent renewables in California, and especially overgeneration of daytime solar photovoltaic (PV) electricity, studies have shown that managed EV charging can lower emissions and contribute to grid stabilization. Furthermore, emerging transportation innovation such as electric automated vehicles (eAVs) and ridehailing can either pose challenges or offer additional tools to further reduce emissions from the transportation system, depending on how policies are shaped. This opportunity underscores the importance of establishing policies and regulations that support “greener” electric vehicle charging by better linking charging to the availability of clean electricity. Existing programs designed to encourage greener charging include rate designs (e.g., EV rates and demand charge mitigation), pilot projects that align charging behavior with renewable output on the grid, and Renewable Energy and Smart Charging bonus credit provisions under California's Low Carbon Fuel Standard. New possible policies include real‐time rates based on locational availability of renewable energy, aggregated demand response from vehicles, and incentives for vehicle‐to‐grid services. At the same time, greener charging alone is not the only goal of these transportation electrification programs.

Project Description: California has many aggressive climate policies, primarily aimed at individual sectors. This study explores untapped policy opportunities for interactions between sectors, specifically between the transportation and the electricity grid. As electric vehicles become more prevalent, their impact on the electricity grid is directly related to the aggregate patterns of vehicle charging. Even without vehicle-to-grid services, shifting of charging patterns can be a potentially important resource to alleviate issues such as renewable intermittency. This study compares, through modeling, projected emissions reductions from managed vs. unmanaged charging. The lion’s share of emissions reduction in the light-duty transportation sector in California will come from electrification, with a cumulative 1 billion tons of CO2 reduction through 2045. Decarbonization of the current grid leads to an additional savings of 125 million tons of CO2 over the same time-period. Potential state policies to exploit synergies between transportation electrification and grid decarbonization could reduce cumulative emissions by another 10 million tons of CO2. These policies include strategic deployment of charging infrastructure, pricing mechanisms, standardizing grid interaction protocols, and supporting grid infrastructure requirements.

Status: Completed

Budget: $35,000

Project Partner(s): California Department of Transportation, California Energy Commission, and California Public Utilities Commission

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Policy Brief(s):
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