The transportation sector is the largest contributor to greenhouse gas (GHG) emissions in the United States, accounting for nearly a third of 2020 emissions. Compared to traditional cars, EVs produce (on average) half to a third of the emissions per mile. Consequently, there is enormous public and political interest in EVs as a promising pathway to reducing GHG emissions. Indeed, the Infrastructure Investment and Jobs Act dedicated $7.5 billion to develop a national charging infrastructure network. In complement, the Inflation Reduction Act established over $12.4 billion in tax credits for EV purchases, among a host of other EV-supportive provisions intended to drive increased EV ownership and use.

However, increased EV adoption introduces a new challenge. The default charging method for most EVs is unmanaged charging. With this method, charging begins when a vehicle is plugged in and continues at constant power output (in kilowatts, or kW) until the vehicle is fully charged. This type of charging is referred to as “unmanaged” because it lacks a coordinated effort to control the time and power of the charging and it fails to account for broader demand on the local power grid. While unmanaged charging is lower-cost and more straightforward from an equipment and installation standpoint, it poses critical challenges for both the consumer and the power grid.

Because EV owners usually charge their vehicle in the evenings, when residential household energy demand is also at its peak, unmanaged charging will inevitably lead to peak-time grid overloads and surges in network losses. These overloads will be expensive and disruptive for the electric utility and, consequently, for consumers.

In addition, the unmanaged residential charging pattern is misaligned with peak hours for solar electricity generation, which is greatest during the middle of the day.

Improving the relationship between EVs and the power grid through smart charging is a promising solution. Smart charging, or vehicle-grid integration (VGI), refers to any technology or policy designed to mitigate the impacts and costs of EV charging on the electrical grid by controlling the time charging occurs, power output, direction of power flow, and/or the location where charging occurs. Shifting from unmanaged charging to smart charging can avoid or postpone costly infrastructure upgrades, offer financial savings for consumers, smooth intermittency issues, and enhance grid stability.

The success of smart charging in a residential setting depends on both the technological readiness and widespread acceptance by consumers, yet little research has been conducted to understand smart charging from a behavioral perspective. This oversight is consequential because many benefits of smart charging will only be realized if it is adopted by a significant portion of the population. A behavioral perspective is key to understanding concerns and designing effective, attractive smart charging programs that EV owners are likely to adopt.

Key Findings:

  • We find that 95 percent of respondents are interested in VGI programs, mostly due to the chance to be greener, save energy, and earn a financial incentive.
  • However, 94 percent of respondents are concerned with at least one feature of VGI, most commonly data privacy, battery life, and charge readiness.
  • Black, Indigenous, and people of color (BIPOC); lower-income people; and female respondents generally report higher levels of concern, specifically about VGI’s impact on data privacy, server control, and battery life.
  • With incentives of $300 per year (for unidirectional programs) to $1,000 per year (for bidirectional programs), 80–89 percent of respondents report being interested in purchasing an EV that can participate in VGI programs.
  • Despite concerns, more than 85 percent of respondents want to be notified of future opportunities to participate in VGI, indicating that with the right information, framing, and incentives, smart charging can be a promising pathway to an electrified future.
Illustration showing unmanaged charging. Illustration showing Unidirectional Smart Charging (V1G). Illustration showing V2G.



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