Inspect first, then recommend
Safe access, system records and evidence from the inverter help narrow down the fault.
Know which number you are looking at
Inverter power is an instant reading, energy is accumulated over time, and smart-meter import or export is not the same as solar generation. Battery apps may show additional flows that make the picture look different again.
Record the system size, normal peak behavior and monthly totals so later comparisons use the same measure.
Season and weather create normal variation
Day length, cloud, panel temperature and shade paths change throughout the year. Compare similar periods and use longer trends before concluding that a system is faulty.
New tree growth, scaffolding, roof work or a changed monitoring connection can create a visible step in the data without a panel failure.
Fault codes and sustained changes need evidence-led checks
Capture exact warning messages, dates and screenshots. A technician can then decide whether remote checks, inverter diagnostics, electrical testing or roof access are likely to be needed.
Common questions
- Why does my solar app show zero while the house still has power?
- The grid supplies the house independently. Zero solar can indicate darkness, a monitoring connection issue, an inverter shutdown or another fault that needs checking.
- Should generation reach the panel system's headline rating?
- Not continuously. The rating is measured under standard test conditions; real output varies with light, temperature, orientation, losses and inverter limits.