Maintenance is not a promise of gains
A drop in output can have several causes. Cleaning won’t fix an electrical fault or a breakdown. If in doubt, have the installation checked by the appropriate professional.
Describe the situation without taking risks
From a safe, accessible spot, note the type of deposits and where the panels are. Don’t climb onto the roof to prepare a quote request. Access is assessed before the work.
Respect the equipment
Pass on the manufacturer’s maintenance recommendations if you have them. The choice of water, equipment and working conditions must respect the module and the constraints of your installation.
For an assessment of your needs, request a quote.