1. Keep the starting records
Keep the layout, models, serial numbers, commissioning tests, warranties and generation forecast. Identify meter, inverter and app data, as they may measure different flows. Specify who monitors alerts and how to reach service. Check access to historical data if you change providers.
2. Compare relevant periods
Assess generation alongside weather, season, shading, snow and system availability. Lower feed-in energy may also reflect higher on-site consumption. Separate missing data, lost communications and stopped generation. For a persistent discrepancy, send the period, readings and status codes to the professional; one percentage threshold cannot diagnose every installation.
3. Assess whether cleaning is useful
Swissolar describes contamination from dust, pollen, leaves and bird droppings. Rain can remove ordinary dirt; some sites need particular attention. Have the actual condition and expected benefit assessed before ordering cleaning. Request a price covering access, protection, method, water and runoff management under the applicable requirements.
4. Follow equipment instructions
Use qualified professionals for roof work and electrical inspections. Specify the cleaning products, tools and water characteristics permitted by the manufacturer; do not apply one method to all panels. Plan access and fall protection. Snow, damaged glass or a suspect connector need an appropriate assessment without walking on modules or opening equipment to investigate.
5. Define the service and its cost
Compare included services, justified frequency, travel, roof access and alert handling. Check requirements specific to a battery or other equipment. Separate preventive maintenance, troubleshooting, repair and replacement. After service, keep the findings, measurements, work, parts and date, then compare generation over a suitable period. Monitoring does not guarantee fault-free operation.