The state of EV charging in America: Harvard research shows chargers 78% reliable and pricing like the ‘Wild West’

Headshot of Dr. Omar Asensio

BiGS Actionable Intelligence:

BOSTON — New data-driven research led by a Harvard Business School fellow reveals a significant obstacle to increasing electric vehicle (EV) sales and decreasing carbon emissions in the United States: owners’ deep frustration with the state of charging infrastructure, including unreliability, erratic pricing, and lack of charging locations.

The research proves that frustration extends beyond “range anxiety,” the common fear that EV batteries won't maintain enough charge to reach a destination. Current EV drivers don’t see that as a dominant issue. Instead, many have "charge anxiety," a fear about keeping an EV powered and moving, according to scholar Omar Asensio, the climate fellow at HBS’s Institute for the Study of Business in Global Society (BiGS) who led the study.

Asensio’s research is based on a first-ever examination of more than 1 million charging station reviews by EV drivers across North America, Europe, and Asia written over 10 years. In their reviews, these drivers described how they regularly encounter broken and malfunctioning chargers, erratic and secretive pricing, and even “charging deserts” — entire counties in states such as Washington and Virginia that don’t have a single public charger and that have even lost previously available chargers. EV drivers also routinely watch gas-engine vehicle drivers steal parking spots reserved for EV charging.

Asensio said that listening to the current drivers — owners rather than potential buyers — provides a new window on the state of America’s charging system because drivers are incredibly candid about their experiences.

“It’s different than what any one company or network would want you to believe,” said Asensio, who is also an associate professor at the Georgia Institute of Technology. He added that most charging providers don’t share their data and have few regulatory incentives to do so.

Research: EV chargers less reliable than gas pumps

One of the study’s main findings, discovered using customized artificial intelligence (AI) models trained on EV review data, is that charging stations in the U.S. have an average reliability score of only 78%, meaning that about one in five don’t work. They are, on average, less reliable than regular gas stations, Asensio said. “Imagine if you go to a traditional gas station and two out of 10 times the pumps are out of order,” he said. “Consumers would revolt.”

Elizabeth Bruce, director, Microsoft Innovation and Society, said, "This project is a great example of how increasing access to emerging AI technologies enables researchers to better understand how we can build a more sustainable and equitable society.”

Asensio’s research is timely as U.S. policymakers, entrepreneurs, automakers such as General Motors and Tesla, and others grapple with how to develop the nation’s charging network, who should finance it, and who should maintain it. Because charging influences vehicle sales and the ability to meet emissions targets, it’s a serious question. EV sales have climbed, topping 1 million in 2023, but concerns over batteries and charging could slow that growth.

Today, there are more than 64,000 public EV charging stations in the U.S., according to the U.S. Department of Energy's Alternative Fuels Data Center. Experts say that the nation needs many times more to make a smooth, sustainable, and equitable transition away from gas-powered vehicles — and to minimize the anxiety surrounding EVs.

“I couldn’t even convince my mother to buy an EV recently,” Asensio said. “Her decision wasn’t about the price. She said charging isn’t convenient enough yet to justify learning an entirely new way of driving.”

Reviews give voice to 1 million drivers

An economist and engineer by training, Asensio has been studying EV infrastructure since its infancy in 2010. At that time, the consensus among experts was that the private sector would finance a flourishing charging network, Asensio said. But that didn’t happen at the scale expected, which sparked his curiosity about how the charging market would emerge at points of interest rather than only near highways.

To get answers, Asensio focused on consumer reviews “because they offer objective, unsolicited evidence of peoples’ experience,” he said.

The smartphone apps that EV drivers use to pay for charging sessions allow them to review each station for factors such as functionality and pricing in real-time, much like consumers do on Yelp or Amazon. Asensio and his team, supported by Microsoft and National Science Foundation awards, spent years building models and training AI tools to extract insights and make predictions from drivers leaving these reviews in more than 72 languages.

Until now, this type of data hasn’t existed anywhere, leaving consumers, policymakers, and business leaders — including auto industry executives — in the dark.

Research reveals five facts about EV life

Here are some of the top findings from Asensio’s research about public EV charging stations:

  • Reliability problems. EV drivers often find broken equipment, making charging unreliable at best and simply not as easy as the old way of topping off a tank of gas. The reason? “No one’s maintaining these stations,” Asensio said. Entrepreneurs are already stepping in with a solution. For example, at Harvard Business School’s climate conference in April 2023, ChargerHelp! Co-founder Evette Ellis explained that her Los Angeles-based technology startup trains people to operate and maintain public charging stations. But until quality control improves nationwide, drivers will likely continue to encounter problems.

  • Driver clashes. One consumer complaint that surprised Asensio was a mysterious gripe from drivers about “getting ICE’d.” The researchers didn’t know what it meant, so they did some digging and discovered that ICE stands for “internal combustion engine.” EV drivers adopted the term to grouse about gas-fueled car drivers stealing their public EV charger spots for parking.

  • Price confusion. Drivers are vexed by the pricing they encounter at public charging stations, which are owned by a mix of providers, follow different pricing models, and do not regularly disclose pricing information. The result is often surprises on the road. As one reviewer wrote, “$21.65 to charge!!!!!!! Holy moly!!!! Don’t come here unless you are desperate!!”

  • Equity questions. Public charging stations are not equally distributed across the U.S., concentrated more heavily in large population centers and wealthy communities and less so in rural areas and smaller cities. The result is that drivers have disparate experiences, well-served in some areas and starved in others. Some parts of the country have become “charging deserts,” with no station at all.

  • Commercial questions. Commercial drivers in many areas can’t find enough public EV charging stations to reliably charge their cars. Here too, drivers are having very different experiences, well-supplied in some areas and not in others.

‘Wild West’ pricing is a major pain point

The research shows that EV drivers are dissatisfied with EV charging station pricing models, likening the situation to the “Wild West.” Indeed, vehicle charging is both unregulated and non-transparent.

Pricing can vary substantially by facility, level of demand, time of day, and other factors, including the type of charger available. A 45-minute fast charger may have one price, while a traditional charger that takes 3 to 5 hours may have another. Pricing can also change by the hour, based on market conditions.

Unlike traditional gas stations, which often display fuel prices on lighted signs, EV stations rarely advertise what charging will cost. Drivers often arrive without any information on what to expect or how to make comparisons, because there’s no reliable way for consumers to find the most cost-effective places to charge. “The government has a source that lists all locations, but not in real-time,” Asensio said. “You might need five different apps to figure it out.”

The driver reviews in Asensio’s data reflect the irritation caused by the current system. “People are getting frustrated because they don’t feel like they’re getting their money’s worth,” he said.

Why is the charging network so opaque? Research conducted by Asensio and his colleagues in 2021 found that charging station hosts, in the absence of regulation, have no incentive to share data — and they don’t. Station hosts are typically privately owned, highly decentralized, not well-monitored, and have highly varied patterns of demand and pricing.

The lack of transparency prevents researchers — and journalists — from investigating trends. In stark contrast to headlines trumpeting the ups and downs of gas prices, news organizations are not reporting on differential pricing among EV charging stations.

‘Charging deserts’ emerge

With municipal, state, and federal governments all pushing to increase the number of electric vehicles on the road and decrease carbon emissions, experts agree that America will need more charging stations — a lot more.

Looking only at Level 2 chargers, which top off an EV battery in 3 to 5 hours and are the most common type, S&P Global Mobility estimates a need for 1.2 million nationwide by 2027 and almost twice that by 2030. That’s in addition to in-home chargers.

Of course, that assumes robust growth in EV sales. “The transition to a vehicle market dominated by electric vehicles (EVs) will take years to fully develop, but it has begun,” said Ian McIlravey, an analyst at S&P. “With the transition comes a need to evolve the public vehicle charging network, and today's charging infrastructure is insufficient to support a drastic increase in the number of EVs in operation.”

Making matters more difficult, the chargers that do exist are not evenly distributed. Predictably, the places with the most public chargers installed are those with the highest number of registered electric vehicles, including states like California, Florida, and Texas. Yet, even as the federal government invests billions in new charging stations, many of them along major transportation corridors, places are left behind.

Asensio’s research shows that small urban centers and rural areas attract fewer public charging stations, and in some cases, there are “charging deserts” with no facilities at all — and they may not be where you think.

For example, electric vehicles are popular in Washington state, which ranked fourth in number of EV registrations and sixth in number of public charging stations in 2023. Yet Ferry County, an area outside Spokane with about 7,500 residents, where the average commute is 25 minutes and the median income is about $46,000, had only one charging station for several years. And now there are none.

Similarly, Virginia ranked 11th in EV registrations and 13th in public chargers in 2023. There, researchers found Wise County, an area outside Roanoke and Knoxville, Tennessee, with about 3,500 residents and a median income of almost $45,000. The county has an average commute time of 22 minutes, but there are no public charging stations available.

EV charging presents a classic “chicken and egg” situation, begging the question of whether cars or charging facilities must come first. However, a lack of public charging in areas like Ferry County and Wise County makes electric vehicle adoption difficult.

As American drivers debate whether to swap their gas-powered vehicles for EVs and lower emissions, Asensio said research should play a larger role. Policymakers, auto manufacturers, entrepreneurs, and investors need more and better data to build infrastructure where it’s needed, provide reliable charging, and facilitate EV sales.

“How [else] can we make effective decisions about the economics of EVs?” Asensio said.

General Motors: ‘Anxiety around EV charging’

Omar Vargas, head of public policy at General Motors, emphasized the importance of public EV charging infrastructure to driving EV adoption during an interview with The BiGS Fix at one of BiGS’ business leadership roundtables in Northern Virginia.

“We're looking at what are the best places to install an EV charging station for a community,” Vargas said. “The anxiety around EV charging is an inhibitor to EV adoption.”

Beyond the public investment in rolling out charging infrastructure, GM (whose brands include Chevrolet and Cadillac) has committed $750 million in private capital to the development of EV charging stations. It is partnering with car dealerships and other companies. For instance, GM is testing charging stations at Flying J rest stops.

GM, which reported full-year revenue of $171.8 billion for 2023, also is joining community partnership efforts that are being formed to secure federal dollars through state and local governments. “We're helping that kind of planning, and we're pretty confident that in the next couple of years, we're going to have a vigorous EV charging network in the United States,” Vargas said.


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