More than a quarter of grid battery systems could have quality problems with key fire safety systems, according to a new report on an in-factory audit.
The six-year audit by Denver-based consultancy Clean Energy Associates (CEA) found quality issues in components that identify and suppress fire in 26% of battery energy storage systems (BESS) and defective components that manage temperature in 18%.
The report entailed 320 inspections, factory quality audits on 52 BESS systems and covered a total 30GWh of lithium-ion energy storage projects.
Some 64% of top-tier BESS cell manufacturers were audited worldwide, with a total of 1,300 manufacturing issues identified, CEA stated, adding that problems at factory level could be caught later during project installation and commissioning.
Recharge reported earlier this year how high-profile blazes at lithium-ion battery projects are damaging public confidence in and acceptance of the key energy transition technology.
"The past several years have shown that thermal runaway poses a significant risk to the energy storage industry," CEA stated.
The preponderance of thermal management issues was traced to the fact that "system level" defects played a role in 48% of the quality findings.
CEA said this was due quality control shortcomings in a "highly manual and labour intensive" BESS integration process. Systems were also described as vulnerable to underlying defects with components that were not caught by earlier quality checks.
Issues occurring in the balance of system stage related to defective components and improper integration procedures, while problems in the enclosure stage were more rooted in assembly and transportation.
The audit found strict precision and safety requirements in highly-automated cell manufacturing processes. But this category still accounted for 30% of the quality issues due to lengthy production processes and higher precision requirements "leaving more room for error".
These cell quality findings were quite evenly split between electrode manufacturing — attributed to improper measurement system analysis and process control — and the finishing and assembly of the cells, where improper process and quality control execution was blamed.
The 23% of quality issues associated with modules were blamed primarily on the use of lower levels of automation found on some production lines.
BESS systems were defined as those using multiple batteries to store energy from a power plant or the grid.
Note: Updated version clarifies that problems addressed relate to fire safety systems and in-factory audit rather than field deployment.
