This mostly applies to flat panel style solar collectors, but the advice is relevant for evacuated tube collectors too. Rainwater will keep the panels clean for the most part, but from time to time, and in particular during a hot and dusty dry spell, you will need to do this yourself. Before you start you should consult your owner’s manual, but below are a few rules that apply to most solar collectors.
You should not climb on the roof to clean your solar panels unless you have the proper safety training and equipment. Many manufacturers recommend contacting the installer for maintenance and cleaning of roof-mounted panels. Check with your installer or consult your owner’s manual for detailed instructions on how often your panels should be cleaned.
Cleaning your panels
If your panels are readily accessible, you can clean them yourself. It is not particularly complicated; usually a good hosing off will do most of the job, but you can also use a soft cloth or a soft-bristled brush or broom, and some warm soapy water or glass cleaning agent if they are particularly dirty.
Leaves and debris
Evacuated tube solar collectors often get leaves and sticks stuck between and underneath them if there are trees nearby, and while the collectors themselves won’t get hot enough to ignite them, the presence of leaves and similar debris on your solar collectors may be a fire hazard. If you have safe access to your solar collectors you should ensure that they remain free of such debris.