Sometimes Level 1 is enough
Do businesses really need Level 2 chargers?
By Wayne Garver, member of Gateway Electric Vehicle Association
Nearly all businesses that install electric vehicle (EV) chargers for their employees opt for Level 2. These chargers are typically 6.6kW, require a dedicated 240 or 208 volt line installed with a current rating of 40A, and have a total installation cost in the neighborhood of $2,000. This can be higher in cases where a long or difficult wiring job, or a new electrical panel, is required.
But does a business need Level 2 chargers? To answer this question, consider the distance an average commuter drives to and from work. The graph below shows that most employees drive a relatively short distance, with approximately 85% traveling less than 25 miles one way.
Average miles driven from home to work
Level 1 charging (standard 120 volt outlet) provides a 1.5kW rate of charge, and for the usual 8-hour work day, equates to 12kWh of charge. The average EV has an efficiency of about 4 miles/kWh, so the TOTAL range is approximately 48 miles. When compared with the round trip commuting distance of 50 miles for 85% of employees, it is clear that Level 1 charging is sufficient.
The cost to install a 120 volt outlet is minimal and with little change to existing electrical panels. If single plug outlets of high quality are used, they can have over 4,000 cycles of life and last over 15 years. The outlets are also less prone to vandalism compared to the plug and cable on the Level 2 chargers.
Peak load charging can be expensive
Now look at Level 2 charging by businesses where the charge rate is 6.6 kW. Over 8 hours, the potential work place charge is 52.8 kWh, providing over 200 miles of range. Businesses would likely be willing to pay for 50 miles per charge per employee, but not for 200 miles. Another Level 2 disadvantage is that all of the chargers would be charging when the employees arrive at work, making for a large peak load to the utility company if they don’t have adaptive load balancing capability. On the other hand, Level 1 charging would take less than one quarter of the power (1.5 kW/6.6 kW) and spread the load out during the day.
We need to educate the business community about the potential advantages of installing Level 1 charging outlets. Considering the difference in cost with Level 2 and the stress to the utility grid, Level 1 chargers may be the better option.