Investigators in Iredell County are still sifting the ashes of an Oct. 30 house fire that burned a garage where a Chevy Volt's battery was being charged, but Duke Energy and Progress Energy say it appears neither the plug-in car nor its plugged-in charger was to blame.
The fire sparked concern for both Charlotte-based Duke and Raleigh-based Progress, which have installed free home charging stations in pilot programs for customers who drive Volts and other electric cars.
The National Highway Traffic Safety Administration launched an investigation last week to determine the risk of fire after a Chevy Volt battery is damaged in a crash (see Road Worrier column with reader comments). Bloggers across the country have speculated that faulty plug-in technology started the Oct. 30 house fire.
Damage was estimated at $800,000 for the $1.5 million house near Mooresville, where the Volt and a Nissan SUV were destroyed. The homeowner was one of 65 customers enrolled in Duke's home-charger program.
Garland Cloer, Iredell County's chief deputy fire marshal, said it appears the fire did not start in the electric car. He wouldn't say more about the fire's origin, because investigators for several agencies and manufacturers are still examining the debris.
"It's still under investigation," Cloer said. "It's probably going to be the first of the year before we have a report."
Duke Energy initially advised homeowners enrolled in the program to consider halting the use of their charging stations.
But a spokeswoman said it is clear now that the Siemens-brand charging station was not the cause. She said Duke reassured participants in its program shortly before Thanksgiving.
"We've notified customers they can continue using the charging stations if they want to," spokeswoman Paige Layne said. "We don't believe the charging station caused the fire."
Annie Seiple, a New York-based spokeswoman for Siemens, said the 240-volt charger "was a victim of the fire and not the cause of the fire."
Progress Energy has signed up 100 North Carolina homeowners for charging stations produced under a different brand, AeroEnvironment. Only two have been installed so far. Progress slowed down its program after the Mooresville fire until more was known about the circumstances.
"Once it became clear that it was not the electric vehicle or the charging station, then we continued at full speed," said Scott Sutton, a Progress Energy spokesman.
Duke receives a flow of data from the home charging stations. Layne and Sutton said data transmitted from the Iredell County charger indicated that the fire was heating up the garage as the Volt was being charged.
"The system was charging normally even as the fire was going on," Sutton said. "It was sending a warning: It's getting warmer, it's getting warmer."