Solar Panel Integrity when not in use

[Mainship Pilot]

2 175 Flex Renogy panels with a 40 amp Controller, question……would it make sense to make a cover, let’s say with a moving blanket, to cover my panels while at the slip? Would this prolong the life and integrity of the panels, or is it just a futile attempt at winter projects? ?

 

[ScottC]

I have been using my boat with 6 panels for 13 years and have yet to find any reason to bother covering them.

 

[Snapdragon III]

I would cover them. My boat came with 10 100w Renogy panels that all failed in around 6 years. They were in the tropics and got a lot of sun. All the plastic on the surface got cloudy and they started delaminating. I expect they would last a lot longer in Seattle than they do in the tropics.

 

[Insequent]

Flexible panels probably will benefit, as they have plastic and not glass over the solar cells, and plastic loses transparency as noted above.

For hard panels, I have often wondered whether sitting at the dock on shorepower and thus having nowhere for the solar output to go degrades them. I guess they may heat up a bit more. In 12 years I have not noticed any loss of performance.

 

[Mainship Pilot]

I guess what could it hurt at this point, they are brand new, I installed them a week ago, so I guess I will add one more step in the clean up process when we get back to the dock. Thanks!

 

[Mambo42]

By coincidence I asked my brother in law this question just a few weeks ago. He has worked his whole life on solar panels, designs them and improves them.
Asked him exactly the same question: 'during the winter our solar panels are not delivering any charge to the batteries since we are connected to shore power. Can this harm the panels ?

His answer was simple. If the panels do not deliver any charge (so no amps flowing) the only thing that will happen is that they will warm up a bit. However, since they will never reach temperatures of 60 to 70 degrees (Celsius) and only at those temperatures you would see degradation of the crystals, during winter they cannot be damaged.
Yes, there will be Voltage on the cables, but that is about it. He explained it to me as an electricity outlet in the wall, which is not in use, where you will also find a Voltage, but no amps.

If you would do this during the summer heat, peak of the day, you could reach that high temperature and thus degradation of the panels. So it is always good to have some airflow over the panels to cool them down.

 

[BruceK]

I`ve only ever covered mine to put them to sleep while working on wiring.
When not running a fridge I did not connect shorepower, the panels fed the batts.
Over 10 years I saw no obvious degradation of the panels. Sydney is temperate, but 35C summer days are getting more common.

 

[ScottC]

I should qualify that my comment was about entirely glass panels, which is what I have. I had not given a thought to plastic panels and have no idea what the optimal strategy is for extending their life. Probably a good question to send off to the manufacturer of the panels!