When the system does not deliver.
WHAT CUSTOMERS COMPLAIN ABOUT
Power not lasting through the night Batteries not charging fully The system shutting down under load Equipment not running Performance declining over time
WHAT TO ESTABLISH FIRST
What load is actually connected.
WHY FIRST
Added load is the commonest cause, and it is not the system's fault.
HOW
Inspect, and measure.
WHAT TO CHECK NEXT
Generation: output against expectation
Shading, which may have developed Dirt on panels Connection condition Battery condition and voltage Inverter settings
WHY SHADING MAY HAVE DEVELOPED
Trees grow and buildings are constructed.
WHAT TO MEASURE
Actual output, against the commissioning baseline.
WHY THE BASELINE MATTERS
It distinguishes degradation from a fault.
WHAT BATTERY PROBLEMS TYPICALLY INDICATE
Repeated deep discharge Age Heat Charging misconfiguration
WHAT TO ESTABLISH
Whether the cause is design, installation, component failure or use.
WHY HONESTLY
Attributing your own design error to the customer destroys the relationship and it is discovered.
WHAT TO DO IF IT IS YOUR ERROR
Correct it.
WHAT TO DO IF IT IS ADDED LOAD
Explain with the figures, and propose either reducing load or expanding the system.
WHY WITH FIGURES
It is demonstrable rather than arguable.
WHAT TO RECORD
Every complaint, its cause and its resolution.
WHAT TO ANALYSE
Causes across systems.
WHAT PATTERNS REVEAL
Design assumptions that are wrong, or components that fail.
