Fall 2014
News Briefs

MGE electric vehicle charging program

MGE electric vehicle charging program

MGE recently completed a two-year tracking study of electric vehicle owner charging behavior funded partly through the U.S. Department of Energy. A total of 123 vehicles, either all-electric vehicles (EV) or plug-in hybrid vehicles (PHEV), participated in the study. Participants were assigned tracking cards that identified their charging sessions across 26 public charging stations located around the Madison area. Charging behavior of vehicle owners at their homes was also tracked.

MGE wanted to learn how EV owners use charging stations and if the charging technology was reliable.

Some findings

The Chevrolet Volt was the most common vehicle owned by the participants (58 of 123 vehicles or 47%). Volts also accounted for 48% of all charging sessions and 51% of all electricity used at the public charging sessions. The Nissan Leaf was the most common of the EVs. They accounted for 14% of all charging sessions and 15% of all electricity used at the charging sessions. The Tesla Model S and Ford C-MAX Energy recorded the highest average maximum demand, 6.4 kilowatts (kW), for sessions at the public charging stations by newer vehicle models which allow charging at 6.6 kW or higher.

Most participants preferred to charge their vehicle at home. Participants were willing to shift at-home charging to off-peak hours if discounted rates were available or if informed by MGE of a critical system electrical system peak event. Some participants reported the public charging stations were sometimes not available when needed, primarily because gasoline cars blocked access to the charging station or other electric vehicles were using them.

Electricity use at home does increase with vehicle charging. Participants with Leafs and Volts used about 15% of their monthly bill for charging, consuming 4 kilowatt-hours and a peak demand of 2 kW. The highest maximum demand during a home-charging session was 3.7 kW for a Leaf.

Participants strongly believed their transportation choice reduced gasoline use, saved money and improved the environment. They like their vehicles, and are willing to accept some of their limitations, including vehicle range and limited number of public charging stations.

MGE looks forward to serving the electricity needs of EV and PHEV owners in the future. For more information about electric vehicle charging, visit mge.com/ev.