The Fire Department was called about 6 p.m. Friday (4/19/19) about smoke rising from the APS McMicken Energy Storage site. The responding firefighters were evaluating the lithium battery when there was an explosion that left the firefighters with serious chemical and chemical-inhalation burns. One of the firefighters was in critical condition at the Maricopa Medical Center's burn unit in Phoenix and in surgery until 1 a.m. before becoming stable.

This incident illustrates that utility scale battery systems can be very dangerous. Further information is not available as of the posting of this article. As more information becomes available, the Solar Center will provide updated coverage.

 The battery system is one of two identical battery systems installed in late 2016 and became operational in early 2017.

There is a good article on these battery systems on the  APS website at On Edge of Phoenix, APS Tests the Relationship of Solar and Batteries

The McMicken unit is contained at the head of the feeder in an existing substation.

Note, these are smaller, earlier batteries that those described in our earlier APS battery article: APS announces 'Solar after Sunset" battery storage inititative

Recent APS presentation slide on these systems, still no further incident details.