Are you considering charging an electric car the wrong way?

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If you have an electric vehicle or have ever purchased one, you know the mantra that automakers preach: install an affordable Level 2 charging connector in your home and plug it in overnight for many miles of range . But what if it’s just the selfish way? A new study from Stanford University paints a more nuanced picture that prompts greater use of daytime charging away from the commuter driveway.

EV charging standby time

Charging away from home may bring a new mindset for EV buyers, but it’s still early enough in the history of electric cars to set the best standards.

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The paper recommends daytime charging at the workplace or in public places when solar power is most abundant and when the grid is taxed less than late afternoon or early evening. “In our results, it was much better for the network at the production level across all the different metrics we considered,” says Siobhan Powell, lead author of the study, who looked at scenarios in the region. of the 14-state western interconnection of the US grid. .

The benefits of Stanford’s recommendation extend not only to avoiding grid collapse, but also to charging electric vehicles when the cleanest power is available with less reliance on expensive battery storage. . This “make hay while the sun shines” model would be a bit of a flip-flop for traditional utilities and the Department of Energy’s charging dogma that incentivizes charging at night when demand is low, though solar generation is non-existent, a recommendation that dates back to a time when solar and wind power generation were still in their infancy.

home charging

Charging overnight at home (usually in a garage from the pages of Dwell) is commonly suggested by automakers as nirvana for the owner, but it may not be the best for the grid.

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“At Stanford, we work closely with many utilities and this is one of their main concerns: what will charging do to their networks?” said Powell. The answer would seem to be no good, based on a recent moment: on August 25, California decided to ban the sale of new combustion cars by 2035; 13 days later, a heat wave resulted in temporary signs at some electric vehicle charging stations in California asking drivers to avoid using them between 4 p.m. and 9 p.m.

But Powell says the irony “also highlighted one of the benefits of electric vehicle charging, which is that it’s very flexible compared to other electric demands.” Most of us don’t have a choice of when we need air conditioning or when we need to cook dinner, but cars sit idle for the vast majority of their lives, allowing for very flexible as long as a savvy owner or smart grid embraces it.

Daytime charging at work or in public places also helps answer the less inconvenient truth about electric vehicles: More than 30% of U.S. households are in multi-family buildings where residents likely don’t have their own garages. or driveway in which to install a private charging device. .

2019 Mercedes-Benz EQC

If only there were that many open loaders waiting for you in the average workplace.

Daimler S.A.

One caveat to the study is that it was based on pre-COVID data, leaving open questions about how the return to the office will play out and what that means for the potential scale of work billing. . But even if some offices remain uncrowded, with a majority of EVs charging at home, the Stanford team says smart charging, where cars and the network do a smart handshake, can ensure that cars recharge at the cleanest time and not all at the same time. time.

You may have noticed that many public or workplace charging points share a major flaw: there are too few of them, and too many are attached to fully charged cars but waiting for a busy driver to return to work or go shopping. Barring a convoluted robotic charging tender that even Elon Musk has given up on, the answer seems to be ubiquitous charging where virtually any place you can park a car, you can charge it. It’s a massive undertaking the likes of which this country hasn’t seen since American homes were electrified a century ago. But public investment is piling up to support a massive infrastructure project where the business case for installing charging stations (PDF) is seen as a challenge.

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