Arizona Fire Highlights Challenges for Energy Storage

by Jonathan J. Cooper (Associated Press) Arizona’s largest electric company installed massive batteries near neighborhoods with a large number of solar panels, hoping to capture some of the energy from the afternoon sun to use after dark.

Arizona Public Service has been an early adopter of battery storage technology seen as critical for the wider deployment of renewable energy and for a more resilient power grid.

But an April fire and explosion at a massive battery west of Phoenix that sent eight firefighters and a police officer to the hospital highlighted the challenges and risks that can arise as utilities prepare for the exponential growth of the technology.

With an investigation ongoing and no public word on the fire’s cause, the incident is being closely watched by energy storage researchers and advocates.

“This is getting attention, and I think everyone realizes that too many safety incidents ... will be detrimental going forward,” said George Crabtree, director of the Joint Center for Energy Storage Research, a partnership of national laboratories, universities and companies funded by the U.S. Energy Department. “So I think it’s being taken very seriously.”

Nearly all of the utility-scale batteries now on the grid or in development are massive versions the same lithium ion technology that powers cellphones and laptops. If the batteries get too hot, a fire can start and trigger a phenomenon known as thermal runaway, in which the fire feeds on itself and is nearly impossible to stop until it consumes all the available fuel.

Problems with lithium ion batteries have periodically triggered fears following outbreaks of spontaneous fires in Samsung phones, hoverboards and Boeing’s 787 aircraft.

“Anytime you store a lot of energy in a small space you’ve got to be very cognizant of the controls that you have to put in place so that energy doesn’t get out when you don’t want it to,” said Jay Apt, co-director of Carnegie Mellon University’s Electricity Industry Center.

Researchers are working to educate firefighters on how to deal with battery fires. READ MORE

Excerpt from Green Tech Media: The ability to store wind and solar electricity is crucial to the continued growth of clean energy, but the fire showed the risks of battery storage, even when handled by highly experienced professionals.

Utility Arizona Public Service has invested heavily in understanding and operating batteries, well ahead of most of its peers. Fluence, which took the McMicken system online in 2017, helped kick off the industry and has operated since 2008 with a clean safety record (previously as AES Energy Storage).

Inexperience, then, did not play a role in this fire. Neither did any obvious technical malfunction.

“Things worked, by and large, the way they were intended to work; we still had an event," Fluence COO John Zahurancik told GTM. "So we're now analyzing...the combination of things that led to this.”

New details are emerging, after the parties had to invent a painstaking technique to safely remove the burned up battery cells from the otherwise functional batteries surrounding them. The wreckage has finally arrived at a forensic lab in Michigan for detailed analysis.

But the investigation is already reshaping how APS thinks about lithium-ion technology. APS remains committed to a massive expansion of lithium-ion battery facilities to store Arizona's cheap and abundant solar power. The findings will guide new safety frameworks there, but will also inform the industry's growth around the country and the world. READ MORE