How long does it take to charge an electric vehicle? The question is more complicated than it seems, and that's a challenge for the auto industry.
Vehicles have different battery sizes, and charge at different speeds. The same vehicle at different chargers will experience wildly varying charge times.
And no matter what charger a driver uses, an electric vehicle requires a change in habits. That may be an obstacle for automakers who need to persuade sometimes skeptical car buyers to try their first electric vehicle.
Most owners charge at home or at work. The process takes hours, which might sound like an unbearable hassle to owners of gas-powered cars. But for current owners it feels much more convenient than a gas station trip because they're doing other things — in many cases, sleeping — while the battery recharges.
The slowest way to charge is on a standard 120-volt outlet, which adds just a few miles of range per hour.
"I don't have a driveway or a garage so I have to run an extension cord," says Andy Fraser, who parks his Volkswagen e-Golf on the street and plugs it in to a normal household outlet. It takes him 12 full hours to add 50 miles of range.
But 50 miles is all Fraser usually needs. And his car would be parked overnight anyway, when he usually does his charging.
"No big deal," he says.
The next step up is a 240-volt level 2 charger. The speed varies, but 15-25 miles added per hour spent charging is typical.
David Cooper, who drives a Nissan Leaf, used to charge on a standard outlet at work, but persuaded his condo building to add two public level 2 chargers.
"The vast majority of the charging I do now is at home," he says. He plugs his Leaf in overnight, and schedules it to charge between 2 and 6 a.m. In those four hours, it adds around 100 miles of range.
Many shared chargers at workplaces, restaurants and other public locations are level 2 chargers, but they can also be installed at private homes; the cost can range from a few hundred to a few thousand dollars.
Clemens Mendell is a realtor and puts a lot of miles on his Tesla Model X. But no matter how much he drives in a day, his car is ready for him the next morning.
He plugs into the level 2 charger in his garage when he gets home, and the car waits to charge until his electricity rates drop to their lowest levels overnight. The vehicle only spends about three hours actually charging.
He usually sets it to stop charging at 70%, which is better for the battery and provides more than enough range for his daily use.
"Every day I'm leaving the house with a full tank of gas, so to speak," he says. "I certainly don't miss the dirty handles at the gas station and the smell and all of that."
That's a common sentiment from current electric vehicle owners, who describe home charging as a perk — and that's before you consider that home charging is considerably cheaper than paying for gasoline. But for would-be buyers, those lengthy charge times can sound alarming.
And convincing car shoppers that they'll learn to love the charging cable is absolutely essential for the auto industry at a time when mainstream automakers — not just Tesla — are betting big on electric vehicles. General Motors now says the future will be "all-electric," and it's not alone.
"[Over] this next five year period, automakers are investing $234 billion into electric vehicle platforms and parts and plants," says Mark Wakefield, managing director at the consulting firm AlixPartners. "One-fifth of their investment budget is going towards electric vehicles at the moment, and growing over time."
For that bet to pay off, a lot of mainstream car buyers, including people who don't have a strong preference for an electric vehicle, will need to be convinced to plunk down money for a battery-powered car.
Governments have a vested interest in pushing this change to reduce carbon emissions and fight global warming. But buyer preferences are crucial, too. To win over skeptics, automakers have aggressively increased vehicle ranges — the average is now 250 miles, Wakefield says, and rising rapidly — and they're working to bring vehicle prices down to be competitive with gas-powered cars.
But charging times are another potential roadblock. And it's not just home charging. Two words loom large in would-be buyers' minds: road trips.
For trips that involve hundreds of miles in a single day, drivers typically rely on DC fast chargers. These chargers — which are much more expensive to install, and thus rarer — use direct current, rather than alternating current, to charge much more quickly.
Confusingly, not all DC fast chargers are equally fast. A 50kw charger is on the slow end of the scale, while next-generation chargers boast 250kw or 350kw capabilities — well beyond what most vehicles are currently capable of accepting.
And comparing speeds is difficult because chargers work very quickly on a depleted battery, but slow down as the battery approaches full.
But generally speaking, a fast charger can fill most batteries to 80% in less than an hour, and sometimes in less than half an hour. It's harder on a battery and more expensive than charging more slowly, so most drivers typically only use them when they're on lengthy trips.
Joyce Breiner recently visited a Tesla Supercharger at a Sheetz in Gettysburg, Pa., to add more juice to her Tesla Model 3. Tesla has been upgrading its proprietary charging network, and this brand new supercharger was able to add around 160 miles of range in 25 minutes, for about $11.
"I'm going to probably go into the Sheetz ... and get a drink and maybe a snack," Breiner said.
That kind of charge speed is exceptionally fast for most vehicles on the road right now.
Whether it will be fast enough to convince electric vehicle skeptics to make the switch remains in doubt.
"Until you reach parity with what everyone is used to ... call it five minutes to fill up your gasoline vehicle, you're still now basically bringing something that's less attractive to people," says Mike Dovorany, a vice president at the market research firm Escalent.
Companies are working to install more super-fast chargers and to build vehicles that are capable of handling that type of charging to help assuage those concerns.
It's an uphill battle, Dovorany says, because people tend to overweigh the potential negatives when they think about making a change to their habits — even if fast charging could be a relatively small part of their life as an electric vehicle owner.
Dovorany says once people own an electric vehicle, they find a lot to love: electric cars are powerful, quiet and cheaper to maintain. And owners quickly adapt to the new charging routine once they take the car home — Dovorany says most people end up really appreciating that they can charge at home and never visit a gas station.
"But it's super hard to convince people before they've owned an [electric vehicle] how much they're going to like that," he says. "And so we can't really sell it per se."
STEVE INSKEEP, HOST:
Next, we have a story of a missed opportunity after disaster. This year's record-breaking wildfires have destroyed more than 17,000 homes and buildings across the United States. They have to be rebuilt, and rebuilding them with fire-resistant materials could help them survive the next fire. But an NPR analysis finds that many states do not require that. NPR's Lauren Sommer has more.
LAUREN SOMMER, BYLINE: Daniel Gorham does detective work - not for people, but for houses. He's sifting through a pile of charred rubble, all that remains of a house in Santa Rosa, Calif.
DANIEL GORHAM: Interesting.
SOMMER: Gorham is a research engineer with the Insurance Institute for Building and Home Safety. He's looking for clues about how homes survive wildfires because sometimes they do.
GORHAM: We saw that on one side of the street, there were homes completely unaffected, where across the street - so less than 50 feet away - they were completely destroyed.
SOMMER: Sometimes that's just luck. But other times, Gorham can figure out what made the difference.
GORHAM: There was one home in particular. An ember had ignited the mulch in the backyard.
SOMMER: Most houses aren't ignited by the fire itself. It's the embers, blown up to a mile away. Gorham could see that the mulch burned all the way to the deck. But the deck wasn't made of wood, and the home didn't ignite. He says it shows how fire-resistant materials can be crucial, like for a roof or siding. Even small things can make a difference, like covering up attic vents with mesh so embers don't get blown inside your house.
GORHAM: These building coded for wildfire-resistant construction do make a difference. We know that. We see that in the lab, and we see that in the field.
SOMMER: In California, wildfire codes are mandatory in high-risk areas. Almost every house that burned this year will have to meet them if they're rebuilt. But that's not true across the West. According to an NPR analysis, more than 6,000 homes in other states won't be required to be wildfire resistant.
GORHAM: It does feel very much like a missed opportunity when it's right there. We're right there with the opportunity to build back stronger.
SOMMER: Because in those other states, wildfire building codes have gotten pushed back.
(SOUNDBITE OF ARCHIVED RECORDING)
UNIDENTIFIED PERSON: The first item is Item 7-A.
SOMMER: In Oregon, state building officials began debating wildfire codes two years ago. Firefighting officials like Ralph Sartain of Ashland Fire and Rescue made the case that many cities are growing into risky areas.
(SOUNDBITE OF ARCHIVED RECORDING)
RALPH SARTAIN: We're pushing further and further into the mountains, but we're not doing anything to protect the buildings that we're getting, and we're getting wildfires and wildfires.
SOMMER: But homebuilders on the state's code review council, like Jan Lewis, questioned the need for wildfire codes.
(SOUNDBITE OF ARCHIVED RECORDING)
JAN LEWIS: I think it's unnecessary. I think it's time to allow Oregonians the freedom to choose where they want to live and the personal responsibility to construct their homes to work with that choice.
SOMMER: The wildfire codes did get approved in Oregon, but they're optional. Cities and counties can choose whether to use them. Sartain says only two cities and one county have considered it so far.
SARTAIN: We would love to have seen it as a statewide adoption, but we could barely get it passed as voluntarily applied inside of a city or inside of a county. The homebuilders would not allow it in any way, shape or form on a statewide basis.
SOMMER: Homebuilders say their concern was cost. Justin Wood of the Oregon Home Builders Association says the codes could add several thousand dollars.
JUSTIN WOOD: It's a real-world issue that we have to figure out how to incorporate the costs of these increased things.
SOMMER: Still, independent studies have shown it can actually be cheaper. And Wood personally sees the need.
WOOD: I think if you're going to be building houses up in wooded, forested areas, I would take measures to protect the home.
SOMMER: Homebuilding groups in Colorado have also opposed statewide wildfire building codes, which means thousands of homeowners in Colorado and Oregon are deciding how to rebuild for themselves.
CHRISTIANA RAINBOW PLEWS: I actually didn't know that my own home had burned for a couple of days.
SOMMER: Christiana Rainbow Plews is fire chief of the Upper McKenzie Rural Fire Protection District in central Oregon. In September, she and her crew responded to a brush fire that turned into an inferno. Hot weather made vegetation bone dry, conditions that climate change is making worse.
PLEWS: It was really just a perfect, perfect setup for a disaster like that.
SOMMER: More than 400 homes burned, including her own. Now she's just starting the slow process of rebuilding. She plans to use fire-resistant materials, which isn't required, but she thinks others in her community will struggle with that.
PLEWS: If they were underinsured or not insured, what they can afford may not be what they actually want. They may have to settle for something that's less fire resistant.
SOMMER: It's a lower priority, she says, when your basic needs aren't met. Months later, hundreds of people are still in hotels.
PLEWS: It's awful, and the morale is just, you know, rock bottom.
SOMMER: It's why without help, the months after a disaster are actually the hardest time to prepare for the next one.
Lauren Sommer, NPR News. Transcript provided by NPR, Copyright NPR.