A team of engineers at the University of California San Diego (UCSD) recommends expanding fast-charging stations for electric vehicles as campuses and businesses start planning for a post-pandemic world.

Their recommendation is based on their study of charging patterns for electric vehicles on the UCSD campus from early January to late May of 2020, after the university moved most of its operations online. The researchers say the findings, published in the Journal of Renewable and Sustainable Energy, can be applied to a broader range of settings.

Workplace charging is a critical enabler of carbon-free transportation as the electrons consumed primarily come from solar power plants, as opposed to at-home charging, which occurs at night and relies more on fossil fuel power plants.

—Jan Kleissl, senior author

It’s the first time that a research team gathered information on workplace charging patterns for electric vehicles during the COVID-19 pandemic. As expected, charging declined significantly once most campus operations became remote. Also as expected, charging at the campus’ medical center was less impacted as medical facilities continued most in-person operations and healthcare workers and patients kept using those charging stations.

This reflects nationwide trends. Vehicle travel in the United States declined by about 40% from mid-March to mid-April 2020, according to the National Bureau of Economic Research.

But DC fast chargers that provide a full charge in about half an hour were less affected than Level 2 chargers, which provide a full charge over eight hours. Energy dispatched at Level 2 chargers on the main UC San Diego campus decreased by 84%. DC fast charging initially dropped by 67%. These stations quickly returned to near-normal usage in a short period of time, unlike Level 2 charging stations.

This finding reinforces ongoing efforts to deploy at least an additional 20 DCFCs primarily on the perimeter of campus in order to serve both UC San Diego commuters as well as the general public in need of recharging.

—Byron Washom, UCSD director of strategic energy initiatives and co-author

Only four out of 100 stations in the study were fast-charging. More broadly, in the United States, only a small fraction of charging stations are fast-charging.

The study looked at 100 charging stations in 28 parking structures. Specifically, researchers found that from 11 March to 20 May 2020:

• Charging on the main campus dropped by 84% from pre-pandemic levels

• Charging dropped by 50% at the parking structures at the UC San Diego medical center locations

• Charging at DC fast charging stations initally dropped by 67% before going back up to near pre-pandemic levels

Charging will likely not resume back to normal even after the pandemic ends, the researchers say.

Commuting patterns based on five days a week in the office are unlikely to resume, however, as employers may allow more telecommuting even after the end of the pandemic.

—Jan Kleissl

Resources

• Graham McClone, Jan Kleissl, Byron Washom, and Sushil Silwal (2021) “Impact of the coronavirus pandemic on electric vehicle workplace charging”, Journal of Renewable and Sustainable Energy 13, 025701 doi: 10.1063/5.0038641