Storing electricity on a large scale has been deemed impractical for more than a century, but is now within reach as power companies develop smart grid technologies.
Duke Energy has been experimenting with battery storage in Charlotte for the past year, and Progress Energy is planning to test industrial batteries in this state soon.
Officials from both companies briefed regulators late last month on the potential of battery storage as part of their smart grid strategy. The N.C. Utilities Commission just released the transcript of the Jan. 26 presentation.
Batteries would back up intermittent renewable resources, such as solar energy and wind power, by storing the clean electricity until it is needed during times of peak energy demand.
"Individual home battery storage units may become quite popular as we move forward," said Rebecca Harrison, director of Progress Energy's Smart Grid Program. "If you have a photovoltaic system on your house, you could also have battery storage, which would make that a much better combination."
One potential source for the batteries could be electric vehicles, she said. As car batteries become less efficient over time, they could be recycled into backups for rooftop solar arrays, which wouldn't require the high performance automobile batteries.
The nation's first commercial plug-in vehicle, the Chevy Volt, is expected to become available this year.
"They're going to look at repacking those batteries for a home storage unit," Harrison told the Utilities Commission. "There's been a lot of movement in the last couple of years in this area."
Large-scale adoption of batteries is still seven to 10 years away as new technologies are developed and prices come down, Harrison said.
"Smart grid" refers to an automated, digital power delivery network that eventually will replace the nation's aging electro-mechanical grid.
By using advanced meters with two-way communication, the smart grid will let power companies provide services they don't offer today, such as remotely shutting off and turning on power, pinpointing power outages to each affected home, giving customers prepay options and generating streaming data on household energy use.
