Some Americans appear increasingly ready to give up their gas cars for electric vehicles. But are the country’s electric grids prepared for them?
The question is a critical one in the quest to address climate change, because transportation is now the single largest sector contributing to U.S. greenhouse gas emissions. EVs are widely viewed as a key way to help change that.
“The broad answer is actually yes, the grid can handle the introduction of large amounts of EVs,” said Matt Stanberry, vice president of Advanced Energy Economy, a business association dedicated to development of clean and affordable global energy systems. “The capability is there,” Stanberry said. “The question is how do you get there.”
Stanberry, along with others looking at the issue, believes what’s needed is not more power, it’s more efficiently and strategically provided power.
“Cars sit around 20, 21 hours a day. There’s plenty of time to charge – so quite a bit of flexibility,” said Dan Bowermaster, program manager for electric transportation at the Electric Power Research Institute, an independent non-profit center for public interest energy and environmental research, which has been looking at grid readiness for EVs.
But he said with new technology coming, such as storage and the ability to use a vehicle’s battery to power a home or to provide extra power to the grid, “Now is the time for everyone to prepare.”
What to think about
Ideally, people would charge their cars when the grid isn’t jammed with activity or when there’s extra power available. That would be in the middle of day in the sunny West when solar power is peaking. In windy areas like Texas, it’s nighttime. In the Northeast, it’s overnight when there’s less power usage. Utilities think they can influence people’s charging behavior by making it more advantageous to charge during those times.
Even before EV use becomes widespread, there are a lot of factors utilities have to think about as they gauge future power needs. Most critically, neighborhood circuits and transmission lines will need substantial changes. For instance, gas stations and highway rest stops one day may be filled with charging stations. That would not only put pressure on the grid, but also do it in concentrations and locations that are different from those that exist now.
With the potential for EVs to become power sources for homes and for emergency back-up power after disasters, utilities will also have to start planning for power to be able to flow in two directions. And they may need figure out how to hook it all to rooftop solar and energy storage.
Researchers at the University of Texas at Austin also point out in a recent report that a low-population state like Maine may need more power to support EVs than you’d think.
“There may not be very many people,” said Todd Davidson, a research associate at the Energy Institute at the University of Texas and co-author on the report. “But on a per capita basis, people in Maine actually are consuming quite a bit of gasoline. If you convert all that gasoline to electricity, then on a per capita basis, your electricity consumption is going to go up a lot.”
These are the considerations the independent system operator that runs the six-state New England grid, ISO-NE, is already thinking about.
There are a lot of variables to consider, said Stephen Rourke, ISO-NE’s vice president for system planning. Where are the EVs going to be – in hubs around the region’s cities? Evenly spread out?
Then there’s how to merge EV deployment with renewable energy.
“We’re really going to have to think about the implications,” he said pointing out that solar power can alter the time of day when the grid has the most excess power. “Then you pile a bunch of EVs on top of that. Just what does that mean?”
What’s happening now
Utilities scattered around the nation have begun pilot and demonstration projects largely focused on changing people’s behavior so they don’t plug in their cars at what is generally peak electric usage time.
Con Edison – the iconic utility that serves New York City and some of its suburbs – is already past the pilot stage for its incentive-driven charging program. Begun in April 2017 as a 100-car pilot, it went full scale that July and now includes about 1,000 private vehicles, plus about 750 fleet vehicles in New York City.
The goal is to get people with EVs to charge them between midnight and 8 a.m., the lowest electricity usage period in Con Ed’s system.
Working with an outside technology vendor, Con Ed provides participants with a connector that collects charging data.
Incentives come as e-gift cards from Amazon and others. Participants get cards worth $150 to $200 just for signing up. For every month they keep the device installed and charge at least once in Con Ed territory, they earn $5, plus an additional 10 cents for every kilowatt-hour they charge between midnight and 8 a.m. And during summertime, when air conditioners are often sucking up electricity, participants can earn another $20 if they don’t charge between 2 and 6 p.m.
Sherry Login, EVs programs manager at Con Ed, estimates someone who drives about 10,000 miles a year and only charges between midnight and 8 a.m. could earn $500 a year, not including the up-front payment.
The point for Con Ed is to manage its electric load so it doesn’t need to add additional power stations. “This is why we’re getting ahead of this,” she said. “We don’t want to be caught off-guard in a few years when all the manufacturers are coming in with plug-in electric versions of all their vehicles.”
Con Ed also is running a vehicle-to-grid pilot with White Plains in its suburban service area. The school district has purchased five electric buses. During the summer when they are idle, Con Ed will use their batteries to supply about 75 kilowatts to the grid. The first test will be this summer.
Southern California Edison, which operates in the San Diego area, is taking a different approach. Faced with about 150,000 EVs – up from about 20,000 in 2013 – and loads of excess power in the middle of the day due to output from solar systems, it’s focusing on ways to get people to charge away from home during the day. It’s working with signals sent directly to the EV or charger to ramp charging up or down.
In Massachusetts, the utility Eversource, which operates in three New England states, has already run a six-month pilot that provided home charger rebates to about 100 customers. In return, Eversource controlled charging times. Customers could override, but most didn’t, said Charlotte Ancel, Eversource’s director of energy strategy and policy.
“The pilot has the promise that people will just plug it in and forget about it,” Ancel said.
The goal in Massachusetts is to increase EV use – which quadrupled last year alone – without increasing peak demand, said Judith Judson, the state’s Department of Energy Resources commissioner.
So at the same time the state is promoting EVs, it’s putting in place new plans for energy efficiency, energy storage and additional renewable energy. “It really requires a combination of policies,” Judson said.
“We have a lot of capability to utilize our existing networks and then combine them with innovative new technologies as well as a real focus on efficiency,” she said. “It really does enable us to integrate many, many more electric vehicles into our system.”