Electric vehicles may offer a path to a more sustainable transportation future. But they also might drive up electricity prices if they are charged during times of peak electricity demand, says a new study from Carnegie Mellon University.
The research found that optimally varying the charging speed of plug-in electric vehicles can cut the electricity cost in half.
Although plug-in electric vehicles currently make up a small percentage of the vehicle fleet, federal and state subsidies are promoting electric vehicle sales, and they may become a significant portion of the fleet in the future, the research said.
If owners regularly plug in these electric vehicles when they get home from work, this would add to greater demand, when the most expensive power plants are running.
Controlled charging can shift loads later in the night when cheaper power plants are again available, according to the research. Controlled charging could also help to manage fluctuations from renewable energy sources like wind and solar power, which change their output as the wind changes and as clouds pass by.
Now it is cheaper to charge an electric vehicle than fill up a gasoline vehicle, but allowing grid operators to control electric vehicle charging speed could reduce these costs further. “We see additional savings up to $70 per vehicle each year or even higher for systems that expect new power plant construction and systems with a lot of wind power,” the researchers said.
The researchers warn that more study is needed to understand all the implications of controlling electric vehicle charging.
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