Electric vehicle pilot study results

Ten WH members who own an electric vehicle participated in a 12-month EV pilot study.

WH recruited 10 members who own an electric vehicle (EV) to participate in a pilot study. Members were asked to plug-in (charge) their EV any time they wanted. The goal was to understand what times people would charge and how much extra load would be put on the distribution system. For our data assumptions, we used an estimate of 18 percent EV adoption rate by 2030. Part of WH’s job as your utility provider is to prepare for changes in energy demand.

What did WH learn?

  1. There is a significant increase in load (40-45 percent) when an EV is added to a home.
  2. During the warmest six months of the year, energy usage was 25 percent lower than during the coldest six months due to EV battery needs.
  3. Charging on off-peak hours is beneficial to both the member and WH.

Energy use increases were partly due to the EVs being plugged in to charge around 5 p.m. This time is when people commonly return home and begin cooking, washing clothes, and using the TV. This sudden spike in energy use causes a peak in electricity demand. When EV charging is added at the same time, it further increases the demand for power.

Second, EVs use 25 percent less energy during the warmer months than the colder ones. Cold weather drains an EV’s battery faster, and as a result, members tend to plug them in to charge more often and for longer periods of time. So, the amount of power used during the year is not constant.

Third, the study confirmed that by charging on non-peak times, EVs are beneficial to both members and WH. WH has an EV Storage Charge Energy-Saving Program. On the program, WH provides power to the charging station for $0.06 per kWh, where the general service rate is $0.094 per kWh plus Power Cost Adjustment. Members are given an incentive to participate in the program, and WH benefits by not increasing peak demand times. In addition to the lower rate, WH also offers rebates on the charger itself.

During this study, WH developed a partnership with ZEF Energy, Minnesota and Wisconsin’s largest independently-owned and operated D.C. fast charging network, and network software operator using its ZEFNET cloud solution. ZEF Energy also makes charging stations which can be controlled to only charge an EV during “off peak” hours. For example, a person can return home from work, plug in their EV and leave it until the next morning and the charging station understands what time to charge (typically overnight from 11:00 p.m. – 7:00 a.m.).

While WH has concluded this study, we are continuing to evaluate data, programs and offerings based on the results. In addition, one of our power suppliers, Great River Energy, is also conducting an EV pilot study and will share additional data.

To learn more, contact us at (763) 477-3000.


EV rebate programs