Update July 30, 2020
LG Chem Ltd, the manufacturer of the battery cells, disputes some of the findings in the APS Final report. prepared by DNV-GL. LG Chem retained independent experts to Investigate the cause of the failure- experts who directly participated In the many site visits and direct analysis of the evidence. In fact, the Independent experts retained by LG Chem believe that the evidence rules out DNV-GL's theory regarding the cause of the initial thermal runaway event. However, DNV-GL ignored other experts' views and key evidence without any explanation. So to provide a more complete record, LG Chem is submitting to the ACC a report prepared by Exponent, a recognized expert in the relevant subject matter. See the LG Chem Ltd report to the Arizona Corporation Commission
Update July 18, 2020
APS has posted a Final report on the McMicken Battery Energy Storage System Event Technical Analysis and Recommendations. This is a very detailed report, worth a study by those who have a need for safe energy storage. Much of the technical information also applies to batterpes used in electric vehicles and other smaller applications.
The factual conclusions reached in this investigation are as follows:
There were five main contributing factors that led to the explosion:
The full report is available on the APS website: https://www.aps.com/-/media/APS/APSCOM-PDFs/About/Our-Company/Newsroom/McMickenFinalTechnicalReport.ashx?la=en
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.
Still no report as of 7/5/20
Many others have taken note of this fire such as Littleton (NH) fire chief raises concerns about battery energy-storage facility
Update July 18, 2020
APS has posted a Final report on the McMicken Battery Energy Storage System Event Technical Analysis and Recommendations.
See the full article: https://azsolarcenter.org/update-utility-solar-battery-fire-in-arizona
TEP has upgraded their distribution system and as of December 7, 2021 the following no longer applies. Remaining posted for historical reasons.
TEP customers intending to install a new PV system now need to check that their system can be safely installed and connected to TEP’s grid.
TEP now has service areas that are saturated with PV systems where new PV systems are subject to additional review and requirements under Arizona’s Distributed Generation Interconnection Rules. TEP has prepared DG Saturation Maps showing these areas.
This further described at https://www.tep.com/get-started-with-solar/
This requirement stems from the recent Distributed Generation Interconnection Rules issued by the Arizona Corporation Commission.
Further information is available at:Interconnection of Distributed Generation Facilities
Update: See the related article on tucson.com: New state rules limit rooftop solar systems in some Tucson neighborhoods