Ask PYS: Power

How To Care For My Solar Panels, on May 31, 2018 asked:

My solar panels have been on my boat a few years now. I do clean them with fresh water occasionally to remove bird and other droppings. They are starting to fade a bit, could you wax them? Or would you recommend some other treatment. - Jaap

 

Proper maintenance of your flexible solar panels is important to maximize the energy that the panels produce.  Flexible solar panels accumulate dirt primarily from wind-blown dust, sand, pollen and bird droppings.  When it rains, the water and dust can pile up on the corners or edges of the panel causing a decrease in output.

Try to clean the panels early in the morning or in the evening.  We find the morning is the best time as the dew that has settled on the panels will have softened the dirt. Do not clean your panels in full sun as the water will evaporate too quickly and smear the dirt.  Manufacturers recommend that they be washed regularly with a soft cloth, mild soap and fresh water.  It is important to rinse them completely as any dried soap will affect the performance of the panel.  Do not use any harsh abrasive cleaners or coarse cloths as they will scratch the panels and the scratches will cast shadows which will affect the performance.  Denatured alcohol (methylated spirit) can be used to remove grease.

If contaminants build up or oxidization occurs, it may be necessary to polish the panel, manufacturers recommend Novus brand polish #2 (fine scratch remover).  This must be done by hand as a power polisher can burn the surface.

When it comes to cleaning frequency, it is best to monitor changes in the power output of your panels before and after cleaning.  Even panels with a light dusting of dirt can lose up to 20% efficiency.

Some manufacturers recommend sealing the panels with a water-clear, thin film polymer coating that provides a high release surface, throughout the year. Products such as Plexus, Novus Plastic Cleaner #1, RejeX, Solar Shield and Repel claim to clean, shield and protect the panels however they can make the panels very slippery. 

Solbian and Gioco marine grade solar panels use a techno polymer base on a thermoplastic poly olefin (TPO) matrix.  This allows the panels to be IEC 61701 (salty mist) certified.  This material allows the panels to be manufactured without a frame because the water and humidity cannot pass through.  The backing on the panels is made from plastic that is specifically designed for the marine environment, it is called poly ethylene vinyl acetate.

Things to look for:

Fracturing can be caused by excessive bending during the installation, or by impact.  Fractured photovoltaic cells do not normally cause a total loss of performance, but usually a drop in efficiency. 

Although the junction boxes are waterproof, it is possible for water to get inside due to manufacturing defects or impact.  If this happens, remove the junction box cover and thoroughly dry the inside.

Charge controllers can fail.  If the controller has a display error or you suspect a failure, check all of your electrical connections between the modules, controllers and batteries.  - Jeff