This paper explores the range of approaches and emerging program designs currently used in the United States to match EV loads and renewable energy, with an emphasis on methods that more closely link the timing and location of the EV demand with renewable energy supply.
Traditional methods of renewable energy procurement can be used to match electric vehicle (EV) demand with renewables annually; however, approaches that incorporate the timing of charging have the potential to enable demand to match renewable energy supplies more closely and offer greater grid benefits.
Although programs to date have primarily focused on residential EV owners, time-based elements of EV charging could be incorporated into existing renewable energy offerings for large energy users, such as corporations and cities, to help meet their clean energy goals.
Program structures that offer financial incentives are more likely to yield higher participation rates and thus may be more effective in providing grid benefits.
Charging programs for employees and fleets can be designed to maximize utility and customer benefits through managed charging, which can match renewable energy availability with EV loads.
Network charging with renewable energy has the advantage of ease of use but may be more difficult to implement in a way that closely matches charging times with renewable energy generation, relative to other approaches.
Although a limited number of programs currently offer the ability to charge EVs with renewable energy, approximately a third of customers expressed interest in the handful of programs for which data were collected.