Residential Electric Vehicle Time-Varying Rates That Work: Attributes That Increase Enrollment

EV-specific time-varying rates can effectively shape charging loads.

Find out what factors increase enrollment.

Forecasts show electric vehicle (EV) adoption is going to increase. Without a thoughtful approach to encourage off-peak residential charging, these EVs could lead to costly distribution system impacts and infrastructure upgrades. SEPA gathered empirical research in partnership with The Brattle Group and Enel X that identifies how EV-specific time-varying rates — a form of passive managed charging — can successfully incentivize customers to charge during off-peak hours.

Download this report to discover the benefits of EV time-varying rates and what rate design and program implementation features will increase enrollment in your service territory. The research also includes insights into the current EV time-varying rates landscape, utility motivations for EV rates, and consumer preferences based on utility and consumer survey results. This report was made possible by funding from E4TheFuture and Enel X.

Key Insights

• Customers on an EV-specific time-varying rate were more familiar with the rate rules and more likely to charge off-peak compared to their generic time-varying rate counterparts
• Utility-driven initiatives had significantly higher average enrollment than mandated programs
• Offering a rate for a long period of time is not sufficient to attract customers; utilities that actively market residential EV rates had customer enrollment 1.4 times greater than those that were not marketed
• 70% of the enrolled residential EV participants heard about their time-varying rate through least-cost marketing efforts
• 72% of non-enrolled customers were willing and able to charge their EV during off-peak hours if the rate resulted in savings and was convenient to use

What’s in the report

• A comprehensive overview of residential EV time-varying rates and their managed charging benefits
• Current landscape of residential EV time-varying rates, utility’s motivation for pursuing the rates and their successful marketing strategies, based on a utility survey
• Consumer insights, based on surveys indicating interest of enrolled drivers in participating and identifying the requirements of non-enrolled drivers to participate
• Features of effective time-varying rates contributing to the highest EV customer enrollment based on survey results and lessons learned
• Various utility approaches to EV metering and five case studies on different approaches
• Recommendations for utilities and questions to consider for next steps
• Complete list of available residential EV time-varying rates offered by utilities

Member Only Content

SEPA members can access additional bonus material through the e-store here, which includes a figure library with high-resolution versions of the figures and tables and the corresponding data in Appendix A.