As electric cars grow in popularity, workplace charging becomes more important.
Yet while it provides a convenient option for drivers--especially those without their own garages for charging at home--workplace charging can also pose management problems for the companies that offer it.
The more employees who take advantage of workplace charging in coming years, the more carefully employers must consider access, infrastructure, and energy costs.
Simply filling a parking lot with charging stations isn't always the best way to go, according to advocacy group Plug-In America, which outlined best practices for workplace charging in a recent blog post.
While not offering a one-size-fits-all approach, the group says it hopes to create a baseline for companies looking to promote electric-car adoption at a sustainable cost and with minimal environmental impact.
MetLife electric-car charging station for employee use - Johnstown, Pennsylvania
That could potentially mean foregoing free charging.
While giving something away for free may seem like a good way to get people on board, Plug-In America notes that electricity costs generally aren't a barrier to electric-car ownership.
Plugging in is almost always cheaper on a per-mile basis than filling up with gasoline.
Instead, free charging can actually create too much demand--ultimately reducing the effectiveness of workplace charging through overcrowding and high costs to the company.
Instead, Plug-In America recommends charging employees a rate just above the market rate. This also encourages charging at home during off-peak hours, taking some stress off the grid.
Solar canopy at Ford World Headquarters in Dearborn, Michigan
The type of charging equipment installed also needs to be considered: Level 1 (120-Volt) or Level 2 (240-Volt)?
Level 2 charging stations add complexity, the group says, because they provide more range than is needed for the average commute.
Employees could end up paying for more energy than they need, and cars that have been charged to full capacity may need to be moved mid-day.
Many cars charging simultaneously could also attract extra utility-demand fees, the post says.
The solution? Slower--but potentially more predictable--120-volt Level 1 charging using either dedicated stations or conventional wall outlets.
This means cars will likely have to spend an entire workday charging, but it's not like their owners will be going anywhere.
Houston's Tranquility Park Garage with GRIDbot charging stations
On the other hand, anticipating that cars will charge for a full workday allows employers to charge a set hourly rate that's easier to align with electricity use.
Cars also don't have to be shuffled as they finish charging.
With that in mind, Plug-In America recommends mostly Level 1 charging billed at slightly higher than the market electricity rate, with some Level 2 stations available at a higher rate.
The entire blog post is worth reading, as workplace charging continues to grow--and debates over these issues bubble up at more and more companies.