California needs to charge electric vehicles during day, not night, to save grid, study says
For many drivers, a quick charge to top off their charging device is the key to saving the electrical grid.
And even if electric vehicles are more expensive than gasoline, it’s likely that most drivers will plug in at night, says a state-funded study released this month. Charging at night prevents the power grid from being overcharged, the report said.
The California Energy Commission’s report, which was sponsored by the state’s three utilities, points out that charging an electric car overnight can result in a 5 percent or better power grid savings for a short time period.
“The power grid is optimized for times of peak demand,” the report said. “Charging while the grid is at or near peak demand ensures that power plants can operate efficiently, reducing fossil-fuel consumption.”
If power plants are running all night, electric vehicles can also save power when demand is low. That means the energy used to run the car and drive to work becomes renewable, the report said.
“For the power grid, night doesn’t look like 24 hours,” said Chris Paine, a commission spokesman. “It looks like three to four hours at night.”
The report noted that some electric vehicle charging stations are charging for up to five to seven hours, or longer, while others charge for less than 15 minutes. Some vehicles, like plug-in hybrids, are capable of charging at high speed, which is more efficient, the report said.
The commission, which oversees the state’s electric power market, released the study to spur legislation designed to encourage the charging of electric vehicles during times of peak demand during summer. Such legislation could take effect as early as this year, according to the report.
California has nearly 500 public charging stations, the largest of which is a station at the Tesla Gigafactory in South Carolina, according to the report. The report said charging stations are often used as a “backup power source to meet peak loads, such as charging electric vehicles and plug-in hybrids.”
The report said that more charging stations are needed for EV drivers during the day, when the number of EV drivers is typically the largest. It said charging stations could be located in neighborhoods where EV drivers live and