Cleaning: more often than you think
In the dry months, dust on the glass can cut output by 15 to 25 percent. Fortnightly rinsing in summer and monthly during the rest of the year is a reasonable baseline. Clean in the early morning with soft water and a soft brush — never on hot glass.
Quarterly electrical checks
Inspect DC and AC cable insulation, tighten connector joints, verify earthing continuity and check the lightning arrestor. Loose MC4 connectors are the most common cause of hot spots and eventual string failure.
Watch your generation data
Compare monthly output against the same month last year. A drop of more than ten percent that cleaning does not fix usually means a failed string, a degrading module or an inverter running derated.
Annual professional service
Once a year, get IV curve tracing, thermal imaging and an inverter service done. It catches faults while they are still cheap and keeps warranty claims defensible.