# Shelf Life of an Unused Solar Panel?



## Ripon

If I stored a solar panel out of any possible light, even buried it, or put it in a box what is the usable shelf life? Anyone got a clue?
I know they work for 20-25 years in most cases quite easily, but if they are not used do they degrade - just slower I hope?


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## PrepConsultant

Send it my way and I'll test it out for ya....


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## rickkyw1720pf

Ripon said:


> If I stored a solar panel out of any possible light, even buried it, or put it in a box what is the usable shelf life? Anyone got a clue?
> I know they work for 20-25 years in most cases quite easily, but if they are not used do they degrade - just slower I hope?[/QUOTE
> 
> That was a question I asked Brunton before I shelled out the money to buy a solaris 52 portable panel plus I did some checking.
> I couldn't get an actual date but they said most panels kept in sun light will give 80% capacity in 20 to 40 years and it is the sunlight that causes the panels to break down. So with out the sunlight breaking them down they probably will outlast us. Now I know that silicon transistors PN junction breaks down whether they are being used or not and the transistor will become useless in less than 2000 years.


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## Ripon

Oh good - 2000 years - I'm ok then 

This was my understanding but its not a question I see answered much online, and I knew few people
would bury one or box it up for "later." My brother (more money than brains sometimes) has a few
burried at our BOL and I was just curious about their degradation over time that way. I had a feeling
it was use that caused them to degrade but wasn't sure.


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## Nathan Jefferson

I've wondered about this too, but seeing as most new name-brand panels are supposed to be stil 80-90% at 30 years I think shelf life isn't that big of an issue. I would conjecture that not having them up and running, but stored in a proper method would increase the lifespan.

meant to post this before dinner, and now see that Ricky beat me to it!


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## rickkyw1720pf

I am not to concerned about the life of a solar panel, more then likely something else would happen to it. I couldn't tell you how many thing I bought with a life time warranty that I lost. I just wish I could find a storage device that would last that long as a solar panel by itself is not a good stead supply of electricity. As of now Lithium Ion batteries seem to be the best bet for smaller storage but possible to expensive for large systems. Edison batteries would be probably the best bet for long term storage of larger systems.


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## Montana Rancher

I think the better question is how long a battery will last as that is the weak link in storing power.


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## Ripon

Battery usage is a tough one. Again same question. You buy a brand new deep cycle golf cart battery and store it. Is it good stored for 5-10-15-20 years? I would imagine they are ok sometime later but how long? I'm to understand with daily use they work 5-7 years.


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## rickkyw1720pf

Ripon said:


> Battery usage is a tough one. Again same question. You buy a brand new deep cycle golf cart battery and store it. Is it good stored for 5-10-15-20 years? I would imagine they are ok sometime later but how long? I'm to understand with daily use they work 5-7 years.


The best way to store a lead acid battery for future use would be to buy the battery without the acid then add the acid when ready to use. If the battery drains past a certain point because it is not being charged the plates will sulfate and also if the acid goes below a certain specific gravity the batteries can freeze and damage the plates inside. They make chargers specifically for storing batteries for a long time and will keep them charged. It is the cycling of going from different states of charge that wears a battery. I believe that most Lead Acid have about 2000 cycles in them. That is going from full charge to discharge and back at least that is what the manufactures of large electric forklift batteries state. I wonder if anyone has ever looked into using an industrial forklift battery a 2000 lbs 36 volt is pretty common size.


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## MI.oldguy

Dry charged deep cycle batteries, but you have to keep the acid(sulphuric)separate from everything else way far away,where it wont freeze or be exposed to anything living.its very corrosive and highly toxic.as far as solar panels,the company that made them will probably be out of business before the panel dies,from what i have learned about them is,some are still in use since the 50's (when they were invented) and still putting out like 80% of their rated voltage/amperage.


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## PaulS

Dry charged batteries will only degrade due to moisture. Photo-voltaic panels will degrade due to moisture and exposure to light - more-so with exposure to UV but any light will bring on degradation.
Store solar panels in a dry dark place and they will last forever or until they are hit with an E-1 pulse from a HEMP (high altitude nuclear EMP). Batteries that are assembled as "dry-charged" are fine in a cool dry environment but it is impossible to keep moisture from acting upon the cells. They have a shelf life of about a year with very little degradation but you can expect a reduction to about 90 - 95% capacity after five years of storage under "normal" conditions. (30% humidity and 60 - 80F temps) Freezing the dry charged batteries (before adding the acid) will make them last a lot longer but who has room in their freezer for batteries.
The commercial, metal cased batteries are all made in the "dry charged" state. They have the same 2000 cycle life that all lead acid batteries suffer from but you only get 2000 cycles as long as you never go beyond 80% discharge and they are charged completely following that discharge. If you connect a half discharged battery to a charger - even for a short time you have used up one of those 2000 cycles. Proper maintenance and care is also of utmost need to get the full life out of a lead acid battery. (filling with distilled water after charging, keeping it clean and sealed, and keeping it cool during use and while charging)


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## exmilitary

Solar panels last indefinitely. 
Batteries nead maintenance ever so often. Over time they discharge and this is why they must be charged every so often. This includes deep cycle ones. Lead acid batteries must never be allowed to drain completely or it will ruin it. Typical life of lead acid is 2000 chargeand discharge cycles if properly cared for.


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