James Bushnell with the Energy Institute at Haas wrote about a study he co authored looking at whether electric vehicle owners are willing to accept a monthly payment to participate in managed charging. The study offered payments ranging from $0 to $40 per month to give the utility access to controlling when the EV charges. Less than 5% signed up even at the highest payment.

While this study was useful in revealing that flat payments will not induced much customer participation. But that does not mean that pricing cannot be used to enhance participation.

To start, here’s two important observations:

• Clearly TOU pricing is working for EV owners because they start charging at midnight. It is the observation of this incremental response that triggered this study. We can use that knowledge to construct more effective incentives to manage EV charging.
• Customers do not trust their utility and in many places, the utility is doing its best to undermine that trust even further. Of course no one want to let the utility control their EV in some nefarious way. Customers either want to maintain control, or turn that control over to an agent who they trust more or they can switch from.

The solution is to have different sets of TOU periods with staggered starting and ending times. The utility is easily able to have set different starting and ending times so as to smooth the load curve. (Agricultural customers already have a range of tariff options, including picking different peak pricing days.) The first TOU offering could run from 8 pm to 1 am, and the next could run from 8:30 to 1:30, etc. The utility could set the least desirable (e.g., 10 am-3pm) as the default and then offer a limited set of specific start time periods within each circuit as alternative options. Customers could even bid for specific slots. In this way customers maintain control over when they get the lowest prices for charging.

Another option is to have the EV car companies manage the charging. Consumers who buy from that company buy choice (rather than through a mandate as it is with the electric utility) are more likely to trust that company, and may feel that they can switch to a different company if they are unsatisfied. (There might even be third party vendors who can step in.) They would partner with the utility on distributing charging across a neighborhood circuit, maybe even using versions of the shifting TOU period schedules described above. The response would be coarser than direct utility control but it likely would achieve the majority of the load shifting benefits that are needed.