.svg)
Battery Energy Storage Systems (BESS) have revolutionized the way we store and utilize energy, especially with the surge in renewable energy sources. However, as with any technology, BESS are not without their challenges. This blog post delves deep into the root causes of BESS failures, offering invaluable insights and recommendations for improving safety and performance.
Over the past five years, the global installed capacity of utility-scale BESS has seen a dramatic increase. Despite early incidents of fires and failures garnering significant media attention, the overall failure rate has sharply decreased by 97% from 2018 to 2023. This improvement is largely due to lessons learned and incorporated into new designs and best practices.
A BESS Failure Incident Database, initiated in 2021, compiles detailed information on stationary BESS incidents. The database includes incidents as far back as 2011, focusing on those with significant public health and safety impacts. The primary aim is to categorize failures by their root causes and the specific BESS elements involved.
The analysis revealed that integration, assembly & construction failures are the most common, often involving BOS (Balance of System) components such as DC and AC wiring, HVAC subsystems, and safety elements like fire suppression systems. Operational failures, primarily related to controls, were also significant, particularly in early deployments in South Korea where the state of charge (SOC) limits were frequently exceeded.
Transparency around Battery Energy Storage System (BESS) failures remains a significant challenge. Many battery Original Equipment Manufacturers (OEMs) and BESS integrators are reluctant to disclose failure causes, often withholding investigation reports from the public. Legal complexities further complicate this issue, preventing site owners or manufacturers from revealing the nature of these failures. However, using third-party aggregation and anonymization can encourage the sharing of such critical information, fostering advancements in safety research.
BESS failures can result from various causes, including water intrusion, retrofitting errors, operating conditions, coolant leaks, temperature stress, quality control issues, and manufacturing defects. To facilitate meaningful analysis, these causes are classified into distinct categories:
Design: Failures due to the planned architecture, layout, or functioning of components or the system as a whole. This includes fundamental product flaws or lack of safeguards against foreseeable misuse.
Manufacturing: Failures resulting from defects introduced during the manufacturing process, such as foreign material in cells, incorrect physical tolerances, or misassembled parts.
Integration, Assembly & Construction: Failures due to poor integration, component incompatibility, incorrect installation, or inadequate commissioning procedures.
Operation: Failures arising from the system’s charge, discharge, and rest behavior exceeding design tolerances, including incorrect sensing of voltage, current, temperature, or operation beyond designed limits.
Failed Elements:
Cell/Module: Failures originating within the lithium-ion cell or battery module, often beginning with short circuits leading to thermal runaway. Causes include poor cell design, manufacturing defects, incorrect installation, or cell abuse.
Controls: Failures in the sensing, logic circuits, and communication systems that coordinate the operation of the ESS. These include control system incompatibility, installation errors, sensor or control defects, or inappropriate operation limits.
Balance of System (BOS): Failures in any BESS elements excluding cells, modules, and controls. BOS components include busbars, cabling, enclosures, power conversion systems, transformers, fire suppression systems, HVAC, and liquid cooling systems.
An illustrative example is the Elkhorn battery facility fire at Moss Landing, CA, on September 20, 2022. The investigation, shared publicly by Tesla and Pacific Gas & Electric, revealed that rainwater intrusion caused electrical arcing, leading to thermal runaway in one BESS unit. The water ingress point was due to the improper installation of a vent shield, which dislodged an umbrella valve. Additionally, insulation loss alarms were not escalated properly, delaying the response and allowing the fire to spread. This incident was classified as both an integration, assembly & construction failure in the BOS and a design failure of the control system. (Please refer to the article titled “Insights from EPRI’s Battery Energy Storage Systems (BESS) Failure Incident Database, Analysis of Failure Root Cause” published by EPRI for further information.)
Understanding and classifying these failures help in developing better safety protocols and improving the overall reliability of BESS installations. As the industry continues to grow, fostering transparency and learning from past incidents will be key to ensuring safer and more efficient energy storage systems.
- 72% of failures occurred during construction, commissioning, or within the first two years of operation.
- Integration, Assembly & Construction: The most common root cause of failures.
- Controls Failures: Often due to incorrect operational parameters like voltage and SOC.
To mitigate these failures, a comprehensive approach addressing safety at every project stage is crucial from design to decommissioning. Key recommendations within the industry include compliance with updated codes and standards, rigorous workforce training, enhanced manufacturing quality controls, and robust battery monitoring systems.
- Design: Compliance with UL and NFPA standards, site-specific hazard assessments, and early alert systems.
- Integration & Assembly: Workforce training, quality checks, and system-level failure analysis.
- Manufacturing: Improved quality controls, supplier verification, and factory acceptance testing.
- Operation: Advanced battery monitoring and analytics for predictive failure identification.
The future of BESS deployment looks promising, with continued efforts to improve safety and performance. However, transparency and data-sharing within the industry are crucial for further advancements. More comprehensive incident identification and classification will enhance understanding of root causes and the effectiveness of preventive measures.
At Circuit Energy, we prioritize safety and reliability by meticulously addressing all potential failure causes and ensuring comprehensive integration and testing of our Battery Energy Storage Systems. Our commitment to excellence means that every system we deploy is designed, manufactured, and operated with the highest standards to safeguard your energy investments and deliver unmatched performance.
You might also like
this related posts