An investigation is under way after an explosion at a lithium-ion grid-scale battery storage facility in the US operated by the Arizona Public Service (APS) utility.
APS told BEST Battery Briefing today several firefighters and a police officer needed hospital treatment as a result of the “catastrophic failure” of the 2MW/2MWh system at its McMicken facility in the city of Surprise, Arizona.
Firefighters were called to the site after smoke was discovered at the site on 19 April, an APS spokesperson told BBB. The explosion occurred about three hours after first responders arrived.
“For reasons still unknown, the system experienced a catastrophic failure, and four Peoria firefighters, four Surprise firefighters and a Surprise police officer were transported to area hospitals,” the spokesperson said.
“An investigation with APS, multiple government agencies and third-party engineering and safety experts is under way,” the spokesperson added. “We can’t speculate on what went wrong at this time… A thorough investigation will help us determine what exactly failed and why.”
According to the Surprise Fire-Medical Department, four of the firefighters involved were released from hospital on 20 April. The other first responders are reportedly in a stable condition. There was no official confirmation of their condition as BBB went to press.
The McMicken facility was one of two such battery systems APS installed in 2017 to test the technology’s performance in the desert temperatures of the area around Phoenix. The battery systems were supplied by AES— now part of the AES-Siemens Fluence group. The installations marked a return to grid-scale energy storage for APS after a 1.5MW Electrovaya storage system at its Flagstaff facility caught fire in 2012.