To clean solar panels on a roof, follow these steps for safe and effective cleaning:

1. Safety First: Ensure the roof is structurally sound and use appropriate safety gear. If unsure or uncomfortable, consider hiring a professional.
2. Turn Off System: Shut down the solar panel system according to the manufacturer's instructions to avoid electrical risks.
3. Gather Tools: You will need soft brushes or sponges, a garden hose with a gentle spray nozzle, mild soapy water or an eco-friendly cleaning solution (like diluted white vinegar or mild dish soap), a bucket, and possibly a telescopic pole for hard-to-reach areas.
4. Initial Rinse: Use a gentle spray of water to rinse off loose dirt, dust, leaves, and debris from the panels to avoid scratching.
5. Cleaning: Dip a soft sponge or brush in the soapy water or cleaning solution and gently scrub the panels. Avoid harsh scrubbing or abrasive materials that can damage the panel surfaces.
6. Final Rinse: Thoroughly rinse the panels with low-pressure water to remove soap or cleaner residue, leaving no streaks or spots.
7. Drying: Use a squeegee or soft cloth to remove excess water if desired, especially in humid or damp weather.
8. Timing: Clean panels on overcast days or in cooler parts of the day to prevent rapid drying and streaking.

Avoid harsh chemicals, high-pressure washers, or abrasive tools, which can damage the panels. Regular cleaning every few months can improve efficiency by removing accumulated grime and debris. If accessing your roof feels unsafe, or if your panels are heavily soiled, professional cleaning services are advisable. Always check your panel manufacturer’s cleaning recommendations and warranty guidelines before proceeding.