For a solar panel to be listed on the Clean Energy Council list it will have a statutory factory warranty in relation to output over time - typically >94% over 25 years. So why does panel output reduce as time passes? Aside from immediate damage, modules degrade as the chemical composition within the cells separate. Aside from natural degradation there are external influences that will speed up the output reduction, dirt and shade being the main, and physical damage of course.
If we consider that solar panels/modules are a collection of cells wired together in a specific arrangement, then one damaged cell will effect the performance of the others. This is why shade or heavy dirt on one cell will drag down the whole module, a degraded module will drag down the whole array.
Light energy (photons) from the sun need an uninterrupted path to the cells, dirt and dust behave like clouds- reducing output.
Uncleaned and shaded panels will void warranties. As part of warranty claims, manufacturers will require a maintenance record with maintenance done to their specifications - regular cleaning in a specific manner and checking of cables, connections etc.
While the glass on a solar panel looks smooth, it is a surface of tiny peaks and valleys, trapping grime that does not come off with rain alone. If a panel has lost its gloss and has a matt look, then it’s due for a clean.
Cleaning with a pressure washer will void warranties. Water under pressure has potential of getting under the edge strip and making its way to the electrical components within the cell -causing what’s known as an earth fault.
A soft brush is the only approved way to clean a panel, with water that has the iron removed from it. Why? Because manufactures have determined that iron in the water is another potential cause of an earth fault.
The connection plugs between panels can get hot and melt due to water and dirt ingress.
Soldered joints within the cells can run hot due to manufacturing faults, these can get worse over time and are a potential fire hazard.
Above are a few pics of typical faults I come across. The red/orange ones are thermal scans. Another, hot cells caused by hot solder joins. The last being the underside of panels with burnt solder joins.
If your system is not preforming as well as it did when first installed, it may just need a clean. A good clean generally picks up 10 - 15% on a system not cleaned for a period greater than two years. As part of any clean, I do a load test and full inspection. All systems can be repaired, very rarely do they need full replacement.
To schedule a service or stop pigeons, give me a call. Saving solar is all I do.
System load testing, repairs, maintenance, cleaning, pigeon mesh.
For warranty purposes, panel manufacturers specify every 12 months. If warranty is not concern, then for performance, every 2 years is best for maximum output/cost benefit.
Panels have a statutory warranty of 25 years. To maintain this, panel makers specify panels must be cleaned, tested and system inspected annually. Dirt on the panel surface can make each cell work unevenly, this can cause hot spots which degrade the cells total output.
You can easily schedule a service by filling out our contact form or giving us a call. We’ll get back to you promptly to confirm your appointment.
All of the Redlands, Logan to Sunnybank to Wynnumn.