Why It’s Better to Charge EVs at Work Versus at Home


“Shifting current EV charging from home to work and night to day could cut costs and help the grid” — Stanford University News

Home charging options for electric vehicles (EVs) let drivers charge their cars overnight, when utility rates are low. But as more people adopt EVs and charge at night, the extra demand will put unsustainable stress on the power grid. That’s according to findings out of Stanford University, where researchers looked at how increasing EV adoption in the Western U.S. is expected to impact utilities. And these findings have implications beyond just the region.

Alarmingly, the researchers estimate that peak electricity demand in the West is expected to jump 25% by 2035 if nighttime charging trends continue. What’s more, the surplus of cheap, clean electricity that’s normally available during the day, thanks to solar production, is being underutilized. Their proposed solution? Shift EV charging habits from overnight at home to during the day at work.

Let’s look deeper into why daytime charging is preferable and how PowerFlex’s load-managed EV charging solutions can significantly reduce charger installation and operating costs for businesses.  

The Benefits of Daytime Workplace Charging

Rather than scaling up infrastructure to keep pace with increasing driver demand, encouraging EV charging during daylight hours will prove to be less costly both in terms of dollars and harm to the environment. As EV adoption grows and there are more drivers charging at night, more generating capacity will be needed to fulfill the increased power need. That means building more power plants, mostly run on fossil fuels.

Increasing energy storage capacity will also be necessary. Battery energy storage systems can capture excess energy during the day and dispatch it when EV chargers spike demand at night. However, Stanford researchers say over 5.4 gigawatts of storage (equivalent to about five nuclear reactors worth of energy) would be needed in California alone.

If most drivers charged their EVs while parked at work during the day, when states like California see an overabundance of solar production, chargers could be powered with cheap, emissions-free energy. Leveraging solar energy to power EV chargers during the day would also lessen the state’s storage needs by more than 1.2 gigawatts.

Businesses Considerations for Daytime Charging

While shifting EV charging to the daytime when EV drivers are at work is beneficial to the grid, it can present financial and logistical challenges to the businesses that install and operate chargers on their property.

“[An] issue with electricity pricing design is charging commercial and industrial customers big fees based on their peak electricity use,” according to a Stanford news article reporting on the study. “This can disincentivize employers from installing chargers, especially once half or more of their employees have EVs.”

In addition to contending with peak demand charges, businesses must make other considerations when mulling an EV charging installation, including:

  • Ensuring there is enough charging capacity to meet driver demand
  • Implementing charging without sinking capital into costly infrastructure upgrades
  • Maintaining worker productivity as employees jockey for available chargers

When starting an EV charging project, it’s critical that a business work with an experienced charging provider whose solutions include smart, load-managed charging.

The PowerFlex Advantage

PowerFlex uses advanced proprietary software to make EV charger installations as affordable and efficient as possible for corporate and industrial clients.

With Adaptive Load Management® (ALM), consumption across EVs is optimized by controlling power to each charging station individually in real time based on driver inputs and available power. This effectively flattens the facility’s energy usage curve, thus avoiding expensive peak demand charges.

Thanks to ALM, four times the number of EV chargers can be installed at a site versus standard installations, and without significant upgrades to existing electrical infrastructure. With enough ports to go around, employees can remain plugged in for their entire workday instead of needing to stop what they’re doing to move their car to allow others to charge.

Best of all, everything is easily managed through a single-sign-in customer portal that transparently displays real-time data on system performance, EV charging sessions, and revenue.  

About PowerFlex

PowerFlex is a one-stop shop for clean energy solutions. Our smart EV chargers integrate with renewable energy technologies like solar arrays and battery energy storage systems that can further limit reliance on the grid and reduce year-over-year energy costs. Reach out using the button below to discuss how we can tailor a solution specific to your needs.