Authored by: Rimkus Forensic Services Marketing Team
Published 5/1/2026
A battery energy storage system catches fire at a grid-scale facility. Cells in thermal runaway can release flammable gases that may accumulate inside enclosures, and reported incidents have shown that such accumulations may contribute to deflagration conditions extending beyond the initial rack. By the time investigators arrive, the thermal and chemical processes involved have often begun to destroy the physical evidence of their own origin.
Renewable energy equipment failures generate complex claims involving multiple parties, overlapping technologies, and evolving standards. Public analyses of reported battery energy storage system (BESS) failure events suggest that many incidents with documented system age have occurred during construction, commissioning, or the first operating years.
The challenges these incidents create for claims managers, litigation attorneys, and risk professionals differ in important ways from conventional industrial losses.
Key takeaways: Investigating renewable energy equipment failures
Renewable energy equipment failures involve specialized technologies, volatile failure modes, and electronic evidence that may be vulnerable to permanent loss. Several factors may distinguish these investigations from conventional industrial losses:
- BESS, solar photovoltaic (PV), and wind turbine systems each present distinct failure modes that often call for technology-specific forensic expertise
- Electronic operational data, such as Supervisory Control and Data Acquisition (SCADA) logs, Battery Management System (BMS) records, and inverter fault logs, may help establish incident chronology and can be vulnerable to overwrite or loss
- Standards including NFPA 921, issued by the National Fire Protection Association (NFPA), provide an analytical framework investigators may reference
- Root cause analysis typically follows a systematic, evidence-based methodology consistent with how courts evaluate reliability under the Daubert standard
- Evidence preservation protocols typically address self-destructing physical evidence, rolling data retention schedules, and multi-party access pressures
These factors may affect how claims professionals and attorneys evaluate the technical dimensions of these incidents. Rimkus provides forensic investigation of renewable energy equipment failures using systematic engineering methodology. Contact us to discuss specifics.
What types of equipment commonly fail at renewable energy facilities?
Each technology category has its own failure-prone components and characteristic damage signatures. The dominant failure modes differ by system design, operating environment, and how energy is generated, stored, or converted.
Battery energy storage systems
Battery cells and modules are frequently examined components in BESS failure investigations, though publicly reported incidents have involved a range of system elements including controls and balance-of-system equipment. Cooling and electrical balance-of-system components, where coolant leaks or insulation breakdown may contribute to electrical tracking near high-voltage DC bus work, are among the additional areas investigators commonly evaluate. NIST TN 2365, issued by the National Institute of Standards and Technology in March 2026, draws on the Electric Power Research Institute’s BESS Failure Incident Database in its analysis of BESS incident patterns.
Solar photovoltaic systems
Hardware failures at photovoltaic sites contribute to energy losses across operating fleets and, more rarely, to fire events. Beyond the modules themselves, investigators routinely look at DC wiring, MC4 and similar connectors, combiner boxes, and inverter input stages as candidate locations during fire origin examinations. Series arc faults in module-level DC strings may sustain high arc temperatures and, under certain conditions, ignite surrounding polymeric materials.
Wind turbine systems
Gearbox failures are among the more frequently examined reliability and loss-related concerns across the wind fleet, and bearings are often identified as the initiating component within the gearbox. The Gearbox Reliability Collaborative at NREL, supported by DOE, has examined why wind turbine gearboxes often fall short of their expected design life, focusing on bearing failure mechanisms and operating conditions that contribute to premature damage.
What are common failure modes by equipment type?
Failure mechanisms at the component level inform what investigators look for, where they look first, and how they interpret scene conditions and operating data.
Thermal runaway in BESS
NFPA 855 is the NFPA standard that addresses the installation of stationary energy storage systems, including thermal runaway as a design and protection consideration. NFPA Research Foundation testing has documented substantial differences in peak heat release rate between battery chemistries, with nickel-rich modules generally producing higher peak heat release rates than lithium iron phosphate (LFP) modules under the tested conditions. Differences of that magnitude in measured heat release rate may have implications for fire load, sprinkler design, and the survivability of nearby modules during a cascading event.
Arc faults and degradation in solar PV
Series arc faults and ground faults are widely cited in the photovoltaic fire literature as recurring origin mechanisms. NREL and DOE-supported research has examined the conditions under which DC arcs initiate, sustain, and damage adjacent components. Potential Induced Degradation (PID) is a documented mechanism that can cause power loss in PV modules over time.
Bearing and gearbox failures in wind turbines
DOE and NREL research has identified White Etching Cracks (WEC) as one documented bearing failure mechanism in wind turbine gearboxes. Bearing-stage damage can progress to tooth damage and full gearbox loss, and premature gearbox failures relative to expected service life are a frequent subject of forensic investigation and the subrogation cases that follow them.
How are fires and explosions investigated at renewable facilities?
NFPA 921 (2024 edition) is a widely referenced guide for fire and explosion investigators when developing opinions on origin and cause. NIST’s Organization of Scientific Area Committees (OSAC) has approved NFPA 921 for its forensic registry as the consensus reference for fire investigations. It describes application of the scientific method as a sequence of: scene observation and data collection, hypothesis development, deductive testing, and opinion. Applicability depends on jurisdiction, facility type, and the specific circumstances of the incident, and NFPA 921 directs investigators to approach the analysis without presumption as to origin, ignition sequence, cause, fire spread, or responsibility.
BESS fire investigation
Not all fires at these facilities are battery-related. Investigators typically work to eliminate non-battery ignition sources, such as inverter cabinets, balance-of-plant equipment, and adjacent electrical infrastructure, before attributing the incident to a cell or module event. The ATF Fire Research Laboratory technical bulletin on lithium cell and battery handling, published in October 2024, notes that fire-damaged lithium cells can present a risk of delayed thermal runaway and sets out guidance for the safe handling, isolation, monitoring, transport, and storage of damaged cells and batteries recovered from fire scenes.
Laboratory methods may include computed tomography (CT) scanning to identify thermal damage patterns inside intact cells; the cell with the most severe internal damage may be evaluated as a potential initiating cell. Computational fire modeling for BESS is constrained by limits in publicly available battery fuel source data, which is one reason physical examination, electrical forensic investigation, and SCADA reconstruction may play a larger role than fire modeling in early BESS investigations.
Wind turbine fire investigation
Standard fire pattern analysis has known limits inside a turbine nacelle. Patterns can reflect fuel load distribution or ventilation paths and may be less reliable as direct indicators of origin, particularly when the nacelle is partially intact and full of insulation, lube oil, and composite materials. SCADA data, often logged at short intervals, can provide useful evidentiary records for evaluating which system alarmed first and reconstructing the pre-ignition sequence.
Why evidence preservation matters
Renewable energy failure sites present evidence preservation challenges that differ from conventional industrial losses in both kind and urgency. The window to walk a scene, capture electronic data, and lock down physical evidence is often short, and the access window narrows further once site safety, utility, and operator priorities take over.
Spoliation, as discussed within NFPA 921, occurs when physical evidence is destroyed, damaged, altered, or lost in a manner that interferes with the ability of persons with a legal interest in the evidence to examine it and draw conclusions. This risk may be heightened at renewable energy sites, where the failure event itself can destroy physical evidence of its origin.
Electronic operational data may be a high-risk evidence category across these technology types. SCADA event records may be stored on rolling overwrite schedules and can be lost permanently if not preserved or exported promptly. NTSB safety studies have noted that heat and fire can damage battery-related components and complicate post-incident data recovery. DC arc fault evidence on solar PV string wiring, MC4 connectors, combiner boxes, and inverter inputs may also leave metallurgical and char records that may become non-recoverable once remediation, debris removal, or component replacement begins, which is one reason early scoping of electrical investigations is often a priority.
What role does expert witness testimony and litigation support play?
Federal Rule of Evidence (FRE) 702, amended in 2023, requires the proponent of expert witness testimony to demonstrate admissibility by a preponderance of the evidence. The Daubert standard frames trial judges as gatekeepers on expert opinion. Kumho Tire Co. v. Carmichael, 526 U.S. 137 (1999), extended that gatekeeping role to engineering and technical testimony, and General Electric Co. v. Joiner, 522 U.S. 136 (1997), recognized that expert opinions may be excluded where the analytical gap between data and conclusion is too wide.
Root cause analysis reports in these cases typically reference systematic engineering methodologies, including those developed under American Society of Civil Engineers (ASCE) and ASTM International guidance. The ASCE Guidelines for Forensic Engineering Practice, published by ASCE’s Technical Council on Forensic Engineering, discusses the technical, ethical, and legal components of forensic engineering practice and the role methodology and documentation play in how expert witness testimony is evaluated.
Connecting investigation quality to claims and litigation outcomes
Renewable energy equipment failures involve technologies where the failure event itself can destroy the evidence of its own origin, and electronic data may overwrite within a narrow post-incident window. As installed BESS, solar PV, and wind generation capacity grows, equipment failure claims may increase in frequency and technical complexity. A forensic investigation that combines technology-specific expertise, systematic methodology, and, when appropriate, litigation-tested materials analysis can help clarify the technical dimensions of these incidents for all parties. For organizations seeking forensic investigation support, Rimkus has 900+ experts on staff. Contact us to discuss specific requirements.
Frequently asked questions about renewable energy equipment failure investigations
Why is electronic evidence preservation important after a BESS fire?
SCADA event records, BMS data, and inverter fault logs may be stored on rolling overwrite schedules and can be lost permanently if not preserved or exported promptly. Because thermal and chemical processes during BESS failures may also destroy physical evidence, investigators often prioritize both electronic data preservation and early scene documentation.
How can battery chemistry affect BESS thermal runaway severity?
Battery chemistry may affect event severity, with some higher-energy chemistries producing higher peak heat release rates than lithium iron phosphate variants under certain test conditions. More severe thermal events may also increase forensic investigation complexity because physical evidence can be damaged or destroyed during the event.
What Daubert issues commonly arise in renewable energy equipment failure litigation?
Daubert-related scrutiny under FRE 702 commonly centers on whether investigators used a systematic, evidence-based methodology and whether sufficient support exists between the data reviewed and the conclusions offered. Preservation of both electronic and physical evidence, along with documented hypothesis testing, may affect how the methodology is evaluated.
This article is intended to provide general information and insights into prevailing industry practices. It is not intended to constitute, and should not be relied upon as, legal, technical, or professional advice. The content does not replace consultation with a qualified expert or professional regarding the specific facts and circumstances of any particular matter.