The following cases document situations where we attended and resolved simple system issues.
Whilst they illustrate how straightforward faults can remain hidden without systematic, routine sub-systems checks in a complete setup, they also demonstrate how methodical investigation can bring them to light.
This page will grow as a reference of field observations as additional cases arise.
The following examples illustrate how photovoltaic systems can fail or underperform for reasons that are often simple but difficult to detect without methodical investigation.
Each case is paired with relevant findings from regulator reports and industry research showing that these issues are not isolated events.
Regulators rarely publish counts of orphan solar systems. Instead, they report inspection failures, defect categories, recalls and dispute pathways, which together demonstrate the scale of technical intervention required in the sector.
Ref: Clean Energy Regulator – Small-scale Renewable Energy Scheme (SRES) Inspection Program Reports
Obvious finding: Systemic failure buried in installation workflow, originating from momentary inattention and remaining undetected in the absence of routine commissioning checks.
REF: IEA PVPS – Review of Failures of Photovoltaic Modules and Balance of System Components
A retiree invested the totality of his savings in an off-grid solar system designed to power his home as the big plan was to not be connected to the grid any longer. Despite installing approximately 12 kW of PV modules, the system produced only a fraction of the expected output and relied heavily on a diesel generator.
The original installer had stopped responding to calls. Peter was ramping up in frustration and was staring down a litigation process against who he liked to call "Bloody cowboys".
The property was already disconnected from the grid when we arrived. A physical inspection of the array and diode boxes revealed that multiple array extensions were terminated incorrectly.
Half of the strings were effectively wired in reverse polarity due to incorrect connections on diode boxes (combiners). The configuration error meant that a large portion of the arrays contributed little or no usable power yet still satisfied complaisant commissioning in the end.
The issue was corrected by re-terminating the connections and verifying current flow using clamp-meter measurements.
Once corrected, the system returned to its expected output and the generator dependency dropped significantly.
Installation defects are one of the most common issues identified in solar inspection programs.
Regulatory inspections routinely identify wiring configuration errors and incorrect terminations as recurring defect categories.
Ref: IEA PVPS – Review of Failures of Photovoltaic Modules and Balance of System Components
Obvious finding: Negligence in crimping MC4 connectors, no commissioning at all.
REF: IEA PVPS Task 13 – Assessment of Photovoltaic Module and Balance‑of‑System Failures
The homeowner reported that her solar installation could not power a modest appliance, amongst other issues despite clear sunlight.
The installer would not reply to her phone calls or emails.
The system appeared to be producing far less energy than expected.
Panel output testing revealed that only two modules were delivering current on an array of 12.
Inspection of the connectors showed that the ferrules inside MC4 connectors had collapsed during installation, preventing electrical continuity in the affected modules.
Replacing the damaged connectors restored normal output and the system resumed expected performance.
Connector failures and DC wiring faults are recognised contributors to system underperformance and safety hazards.
These issues are regularly cited in defect inspections and safety investigations within the PV industry.
Ref: IEA PVPS Task 13 – Assessment of Photovoltaic Module and Balance‑of‑System Failures
Obvious finding: Wind gradually loosened outdoor cabling, wires weren't secured adequately to IP standards.
REF: IEA PVPS Task 13 – Reliability of Photovoltaic Systems – Faults, Maintenance and Monitoring
A small off-grid property owner believed her battery bank had failed and expected to replace the entire bank.
The system had been assembled through a DIY installation assisted by a well renowned local installer.
Controlled discharge testing was performed to evaluate the battery capacity using electrical loads against Pukert's law.
The batteries were found to retain over 80% capacity.
Further inspection revealed that only one of three solar panels was electrically connected, due to loose wiring in a splitter box.
As a result, the battery bank was rarely reaching full charge and appeared to “die quickly”.
After restoring the missing connections, the batteries charged normally and the system operated as designed.
Performance problems are frequently misattributed to batteries or modules when the root cause is installation or wiring errors.
Solar forensic investigations commonly identify faults related to connectors, cables, and installation practices rather than component failures.
Ref: IEA PVPS Task 13 – Reliability of Photovoltaic Systems – Faults, Maintenance and Monitoring
Obvious finding: Client's habit - working with barn doors wide open in shed - 6.6kW PV system installed at the same time he purchased his 7kW AC unit as per narrative.
REF: IEA PVPS Task 18 – Off-Grid Systems Performance and Reliability Studies
A system owner believed his battery bank was defective because his electricity consumption remained high as his mates were pointing at having a battery would make his bill to shrink even though 2 years ago had got installed a 6.6KW PV setup.
After remote investigation via internet, his battery bank seemed to be performing correctly, however a dramatic load would be depleting it much faster that it had the ability to charge, it would regularly be struggling to replenish before noon in the summer on a sunny day.
A full electrical usage audit was performed by measuring circuit loads during normal operation.
The root cause was identified during a closing conversation as a 7 kW split-system air conditioner running continuously in an open workshop, drawing far more energy than the system could offset.
The solar and battery system were confirmed to be functioning correctly. The issue was related to consumption patterns rather than equipment failure.
Energy-usage misunderstandings are a frequent contributor to solar performance complaints.
In dispute investigations, forensic analysis often distinguishes between system faults and unrealistic energy expectations.
Ref: IEA PVPS Task 18 – Off-Grid Systems Performance and Reliability Studies
Images generated from real-world situations and individuals, with identities kept confidential.
Depending on the system and circumstances, diagnostic investigations may involve:
Electrical testing and load measurements
Thermal imaging
String mapping and configuration checks
Inverter and monitoring data analysis
Installation compliance review
These methods are widely used in PV forensic analysis to determine root causes of system underperformance, failure, or safety incidents.