Skip to main content

Workplace charging could be key to widespread EV adoption

Public charging infrastructure for electric vehicles is expanding, but it is difficult to make a profit on and drivers do most of their charging at home. Charging at the workplace could increase the scale of EV adoption but it would come at the expense of public infrastructure.

The U.S. Department of Energy has deployed numerous initiatives to encourage widespread acceptance of electric vehicles. Possibly the most significant of these was the EV Project, where the D.O.E. tracked over 8,000 electric vehicles and their charging habits over three years by monitoring residential and public ECOtality Blink charging station usage. The project discovered that current Nissan Leaf drivers do 74% of their charging at home while Chevrolet Volt drivers charge at home 80% of the time.

While those results are expected given most early adopters have a garage in which to charge and an additional vehicle, this month the D.O.E. released some important results from the EV Project concerning workplace charging.

A group of 707 Nissan Leafs with access to charging at work were monitored for a two-year period that concluded at the end of 2013. These drivers only did 65% of their charging at home, while 32% of charging events occurred at the workplace and the remaining 3% at public locations. The breakdown for the amount of energy consumed to charge the vehicle was 68% at home, 30% at the workplace, and 2% elsewhere.

This contrasts with the data from Nissan Leafs without access to workplace charging during the same two-year period; in 2012 and 2013, participating Leafs actually charged at home 84% of the time. (The change from the overall results is likely due to the more recent data collection, part of which took place after charging fees had been imposed on public Blink stations that did not exist for much of the project.)

This indicates that workplace charging more than doubles the likelihood a Leaf owner will charge away from home, and confirms that charging stations at the workplace will be used if they are provided.

Another Department of Energy initiative is known as the Workplace Charging Challenge; started in 2013, this project aims to increase the number of U.S. employers offering charging at the workplace by tenfold within five years. 50 employers signed up in the first year, and more are likely on the way with incentives like ChargePoint’s financing plan that removes up-front costs for businesses installing charging stations.

However, it could be argued that $2,000 Level 2 charging stations aren’t even necessary at work. To take full advantage of Level 2 charging cars would have to be moved around during the day, especially if some drivers just want to top off with an extra 10 or 20 miles. Situations like these can even lead to hostility.

Some, like EV device supplier ClipperCreek, suggest that inexpensive Level 1 charging is adequate for the workplace and would accommodate more vehicles. Drivers could still recover 25 to 35 miles of range over the course of the day, and the power demand is very low so that many vehicles could be plugged in at once.

Workplace charging availability has great implications for the EV movement. It can effectively double EV range on workdays – if employees can access charging stations at work, suddenly a Nissan Leaf driver can commute to work 50 or more miles away and charge up during the day rather than be limited to a 35 mile radius. A Volt or C-Max Energi driver can increase his or her all-electric range. It could even make owning an EV feasible for someone that doesn’t have access to charging at home.

On the other side of the coin is the impact workplace charging will have on use of public charging stations. If we’re charging up at home and at work, do we really need charging stations at restaurants and shopping malls?

Well, maybe. That depends on a lot of factors. And whether it is used frequently or not, public charging infrastructure is important for the confidence of current and prospective EV drivers.

However, it is important to note that those EV Project Leaf drivers with access to workplace charging did 98% of their charging at home and work on workdays, and 92% of charging took place at home on non-workdays. It’s only one study, but early results indicate that workplace charging could be very good for the EV industry and very bad for public charging utilization.

If your employer offered charging at the workplace, would you consider buying an EV? Would it make EV ownership more practical? Feel free to leave comments below.


Jp white (not verified)    March 29, 2014 - 6:03PM

Glad to see some emphasis being put towards workplace charging. Educating employers, local govt and the public at large is very much needed. For experienced EV drivers thus study has a certain Doooh! Isn't that obvious factor. However for the general public who have limited and incorrect knowledge of EVs and charging them, this type of article needs wide circulation outside of the EV community.

Especially good to see mention that dedicated EVSE's are not essential for workplace charging. Any good outlet will do. I can recharge my LEAF from 3 bars to full in a 9 hour charge using a 120v outlet. The typical charge at work for me is for a total of 5 bars which is complete by lunch time and helps me do my 60 mile return trip to work and back.

mike w (not verified)    April 11, 2014 - 4:01PM

In reply to by Jp white (not verified)

Wow I'm surprised and shocked at the same time to see somebody use a 120 Volt outlet. I mean I'm glad. Everybody I talk to seems to be in a big hurry and want to park for 9 hours in front of a 7 kw EVSE to charge less than 21 kwh in to a LEAF battery. Everybody seems to be in a big hurry when you have all night to recharge at home it doesn't make sense.

JP White (not verified)    April 12, 2014 - 10:49AM

In reply to by mike w (not verified)

Beggars can't be choosers :-) I use a 120v outlet because it is readily available, and nothing else is.

There are times when I am glad to use a DC Quick Charge unit, sometimes speed does matter. Sitting for 9 hours at work? Speed is much less important. Would I use a 240v unit at work if one was installed? Of Course!! It would save the inconvenience of getting the portable EVSE out of the trunk and hooking it up, a dedicated unit is very convenient, especially when it's raining.