Are You Thinking About Electric Car Charging the Wrong Way?
Are You Thinking About Electric Car Charging the Wrong Way?
A new Stanford study finds that overnight EV charging at home isn’t the holy grail.
Sept. 24, 2022 5:00 a.m. PT
3 min read
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Where and When You Should Charge Your Electric Car
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If you have an EV or have ever shopped for one, you know the mantra that carmakers preach: Install an affordable Level 2 charge connector at your house and plug in overnight for ample miles of blissful clean range. But what if that’s just the selfish way? A new study out of Stanford University paints a more nuanced picture that urges greater use of daytime charging away from the suburban driveway.
The paper recommends daytime charging at workplace or public locations when power from solar is at its most plentiful and when the grid is less taxed than in the late afternoon or early evening. “In our results that was much better for the grid at the generation level in every different metric that we considered,” says Siobhan Powell, lead author of the study, which looked at scenarios in the 14-state Western Interconnection region of the US grid.
The benefits of the Stanford recommendation extend not only to avoiding grid collapse but also to charging EVs when the cleanest power is available with less reliance on expensive battery storage. This “make hay while the sun shines” model would be something of an about-face for traditional utility and Department of Energy charging dogma that urges charging overnight when demand is low, though solar output is nonexistent, a recommendation that dates back to a time when solar and wind power generation were still in their nascency.
