Solar panel lifespan if used only few hours/day

[ttommy185]

Hello . i have two questions if somebody can answer
I know that the life expectancy of solar panels is 20 years.
I think this is calculated assuming the solar panel is working all the hours of the day
But if a panel receives direct sunlight only three hours a day , can i expect its life expectancy to be much longer ?
and another case
a house used only in weekends . panels (offgrid) connected only saturday and sunday, and disconnected the other days. The panels receive the sunlight everyday but because from monday to friday there is no load, i think their life will be much longer because they are in the sun, but they aren't producing. am i correct?
Hope you understood my english
I searched in google but could'nt find an answer probably because it's not a common case
thanks!!

[bcroe]

I suspect disconnecting the panel will have virtually no lifetime effect. Getting it out of the
sun and weather might make a difference. Bruce Roe

[Mike90250]

Time counts in hours of sun exposure. Hide them from the sun, and you still have materials aging too. (glue & sealant)

[littleharbor]

Chances of damaging the panels while moving them into and out of service can end its useful life instantly. Also panels don't just quit working after 20 years. There are 40 year old panels out there still working just fine. Mfg's have found degradation rates as low as 8.3% after 20 years.

[reader2580]

My understanding is solar panels are generating power any time they get enough light. Why even install panels at a location that only gets light three hours per day?

[ttommy185]

thanks to ALL for the reply to my questions!


reader2580: i have no other choice . only that position which receives the fullsunlight only 3-4 hours a day. but it's ok because only few panels are on that side of the house. the others receive the sunlight almost all the day

[reader2580]

thanks to ALL for the reply to my questions!


reader2580: i have no other choice . only that position which receives the fullsunlight only 3-4 hours a day. but it's ok because only few panels are on that side of the house. the others receive the sunlight almost all the day

I'm wondering why you spent money to install any panels that only get 3 to 4 hours a day of sun? This panels probably have a payback of two to three times longer than panels that get full sun all day long.

[SupraLance]

It's my understanding that most manufacturers count their warranty from date of manufacture, so they must believe that if a panel sits in a warehouse in the dark for 7 years before being sold, that still took 7 years off it's useful life.

[AmitBajpayee]

Solar panels have nothing to do with their usage. Their life span is calculated on the factors such as - aging, their exposure to the sun and maintenance. Better the maintenance, longer the life of solar panels. The majority of manufacturers like Agni Solar Systems, Tata Solar etc. offer the 25-year standard solar panel warranty, which means that power output should not be less than 80% of rated power after 25 years.

[J.P.M.]

It's my understanding that most manufacturers count their warranty from date of manufacture, so they must believe that if a panel sits in a warehouse in the dark for 7 years before being sold, that still took 7 years off it's useful life.

Or that it will suffer less deterioration over the storage period and thus present less warranty exposure for the mfg.

[J.P.M.]

Solar panels have nothing to do with their usage. Their life span is calculated on the factors such as - aging, their exposure to the sun and maintenance. Better the maintenance, longer the life of solar panels. The majority of manufacturers like Agni Solar Systems, Tata Solar etc. offer the 25-year standard solar panel warranty, which means that power output should not be less than 80% of rated power after 25 years.

Might be both time and exposure. I'd guess sitting on a black roof in Phoenix might be tougher service than mounted on a vertical white wall in Minneapolis, but a certain amount of degradation may occur simply as f(time) for things like encapsulant, wire insulation, seals, etc.

To the extent a warranty is to be believed and honored, absolute longevity is a somewhat an academic question.

Performance degradation is more pertinent but as a practical matter, difficult to impossible for the average homeowner to verify, and therefore mostly a moot point.