1. Monitor normal output continuously
Keep a baseline for season, weather and shading. Look for persistent deviation rather than reacting to one cloudy day.
2. Perform safe visual checks
From accessible locations, look for obvious debris, broken modules, loose visible conduits, water ingress, corrosion or new shading. Do not open live enclosures.
3. Clean when evidence supports it
Use manufacturer/installer guidance and safe access. Avoid abrasive tools, thermal shock and walking on modules. If roof access is risky, use trained service personnel.
4. Investigate persistent performance loss
Compare inverter logs, alarms, string-level information where available and recent site changes. A technician should diagnose electrical faults rather than guessing from total kWh alone.
5. Keep periodic professional inspection records
Follow the equipment manufacturer and installer maintenance schedule for electrical connections, protection, structure and warranties.