It is common to charge electric vehicles at night. That will be a problem.

It is common to charge electric vehicles at night.  That will be a problem.
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As electric vehicles hit roads across the country, hundreds of thousands of Americans are beginning to learn the ins and outs of car charging: how to install home chargers, where to find public charging stations, and how to avoid the dreaded “range anxiety.” ” “

But as EV owners plug in their cars, a problem looms: pressure on the grid as most drivers continue to charge their EVs at night.

According to a new to learn According to Stanford University researchers, if EV sales grow rapidly over the next decade — and most drivers continue to charge their EVs at home — vehicle charging could strain the power grid in the western United States and peak net demand by 25 increase percent . That could be a problem as the West fights for it leave the lights on amidst heat waves and rising electricity demands.

The first thing to know about EV charging is that it’s not like putting gas in a car. Charging an electric car takes time — while the fastest chargers can charge an EV battery to 80 percent in 20 to 30 minutes, most chargers are slower, taking between two and 22 hours to reach a full charge. That means round 80 percent EV charging takes place overnight at the owner’s home – when the driver does not need the car and has enough time to charge.

However, this charging pattern is at odds with the way electricity is increasingly being generated. The greatest demand for electricity occurs in the evening between 5 p.m. and 9 p.m. People come home from work, turn on the lights, watch TV and engage in other activities that use electricity. Solar panels, on the other hand, produce their energy during midday. The highest power demand occurs just when the solar energy has started switch off for the day.

In the Stanford study, researchers modeled the charging behaviors of residents in 11 western states and then analyzed how those behaviors would impact a power grid that is increasingly migrating to renewable and other clean energy sources.

“Once 30 or 40 percent of cars are EVs, there will be a significant impact on what we do with the power grid,” said Ram Rajagopal, professor of civil and environmental engineering at Stanford University and one of the study’s authors. Even if drivers wait until after peak hours and charge their car at 11pm or later, they are using electricity precisely when renewable energy is not readily available. This could lead to increased CO2 emissions and a need for more batteries and storage in the power grid.

One solution, researchers say, is for more EV owners to switch to daytime charging and charge their cars at work or at public charging stations. Charging electric cars in the late morning and early afternoon when the power grid has excess solar capacity that is not being used puts less strain on the power system and requires less storage. According to the study, in a scenario where 50 percent of cars are electric, a shift from mainly home to a mix of home and work charging could almost halve the amount of storage needed on the grid. Adding workplace and public chargers has the added benefit of helping too renter or those who do not own homes access electric vehicles.

Siobhan Powell, a postdoctoral fellow at ETH Zurich in Switzerland and lead author of the study, says now is the time to plan for expanding public and workplace charging. “We’re not saying ‘stop home charging’ or ‘limit home charging,'” she said. “We don’t want to discourage you any Charge because that’s really important for adoption. But a lot of money is being invested in charging, and we could make charging at work or in public as convenient as it is at home.”

The authors also recommend shifting electricity price structures to better encourage charging during lunch breaks. Currently, some energy suppliers are offering consumers super-cheap electricity rates to charge their cars overnight. For example, PG&E, a California utility offers EV owners Electricity for 25 cents overnight between midnight and 7 a.m. and 36 cents between 7 a.m. and 2 p.m. Ideally, according to Rajagopal and Powell, the lowest rates should apply in the middle of the day to encourage charging when the sun is shining.

Gil Tal, the director of an electric vehicle research center at the University of California, Davis, who was not involved in the paper, said current electric vehicle owners don’t need to worry about their charging patterns. “We don’t have to put the brakes on the introduction of electric cars,” he said. As more clean energy and storage is added to the grid, he argues, many of these problems will be solved.

But he agrees that one of the benefits of electric vehicles is the flexibility in when they can be charged. The shift to daytime charging is helpful, whether that’s by charging at home during the day (for those who work from home) or by providing chargers at work.

Politicians must “set up the chargers where the cars are during the day,” he said.

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