Cleaning PV panels...

System
System Posts: 2,511 admin
in General Solar Power Topics #1
Hi Guys,

I ma new to this forum but it looks like a great place for people who like free energy to hang out!
I have a simple PV system consisting of 3 X 85w roof mounted BP solar panels running 12V. The system seems to provide endless power in abundance despite using multiple dusk till dawn lighting and multiple small consumers during a typical day / evening.

My question is simple... Output readings indicate in excess of 19amps in good sun with voltage of 13.5v plus. Now, this system has been in use for around 5 years and to be honest I would expect to see a dip in output by now, just from natural wear and tear / age. And of course, as the heading indicates, roof mounted panels are going to get grubby. However, the output being harvested would tend to indicate that all is well and that there is nothing hindering them in terms of dirt. Does anyone have any experience of maintaining (high) roof mounted PV panels - should I be cleaning them off regularly? It's an epic job probably requiring the services of a specialist to gain safe access for cleaning :roll:
Regards,
SolarBoy
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Comments

  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    #2
    Re: Cleaning PV panels...

    I have 72 panels and I just get on a ladder about once every couple weeks and hose them off. We get quite a bit of dust and dirt settlement here on the panels and a quick hose job gets them pretty clean.
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #3
    Re: Cleaning PV panels...

    Let the rain do it's thing. If they are really dirty, get a hose and rinse them as best you can.

    As for production dropping off,, you probably won't seen a drop of in production for at least 20 years if then.

    T
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #4
    Re: Cleaning PV panels...

    Clean as needed. They're glass, so anything that will clean glass will work. This includes getting sticky tree sap off if necessary.

    It is important to not clean them in the heat and sun. Early morning or later evening is best.

    The idea that solar panels' output drops off drastically over years has been proven to be somewhat inaccurate by the more experienced users around here. :D
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #5
    Re: Cleaning PV panels...

    The output is supposed to drop a maximum of 20% over twenty years--Many (from what I have read here) seem drop much less--if at all.

    The real issue is that you could never measure a 10% difference in solar panel output with out lab equipment and references to compare light received vs energy output.

    However--Batteries do have a limited life and will eventually fail. And no mater the talk--there does not seem to be anything better out there in the near future for home use.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • peakbagger
    peakbagger Solar Expert Posts: 341 ✭✭✭
    #6
    Re: Cleaning PV panels...

    Your posting doesnt have a location, but I find there is more than enough rain in the northeast to keep mine clean. On occasion I see suggestions on putting "magic elixirs" on panels to keep the snow from building up, I would strongly suggest not using them as Ultraviolet degrades a lot of things and eventually its going to get sticky.
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #7
    Re: Cleaning PV panels...

    i would think that the angle needed for good power production in the uk along with the rains should keep your pvs fairly clean. now once in awhile (years maybe?) they may need wiped clean and would be up to you as to how often that may be done. it may be advisable to do it once a year if anywhere near industrial smoke stacks.
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  • BilljustBill
    BilljustBill Solar Expert Posts: 219 ✭✭✭
    #8
    Re: Cleaning PV panels...
    niel wrote: »
    i would think that the angle needed for good power production in the uk along with the rains should keep your pvs fairly clean. now once in awhile (years maybe?) they may need wiped clean and would be up to you as to how often that may be done. it may be advisable to do it once a year if anywhere near industrial smoke stacks.

    B.B.,

    Your "angle" idea made me reflect on all those angles of any typical automobile.

    As I pass by the local dealerships at very early times of the morning, I see a crew out washing the line of cars in both new and used lots. I know they don't have the time and manpower to wash and spot free dry all those cars.

    Is there a product that goes into a low pressure stream of water that not only cleans a glass/clear coat surface, but also sheds water to prevent water spots that could be used in PV panel cleaning?

    Bill
    Bill
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #9
    Re: Cleaning PV panels...
    BilljustBill wrote: »
    B.B.,

    Your "angle" idea made me reflect on all those angles of any typical automobile.

    As I pass by the local dealerships at very early times of the morning, I see a crew out washing the line of cars in both new and used lots. I know they don't have the time and manpower to wash and spot free dry all those cars.

    Is there a product that goes into a low pressure stream of water that not only cleans a glass/clear coat surface, but also sheds water to prevent water spots that could be used in PV panel cleaning?

    Bill

    Yes. "JetDry" You use it in your dishwasher. Pretty expensive for washing cars or panels, though. :p
    Perhaps there is a commercial-grade equivalent we poor consumers aren't privy to? Probably built-in to the car wash soap.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #10
    Re: Cleaning PV panels...

    BjB,

    That was Niel talking about the "angle".

    My panels are on a 2nd story roof and I used a "Windex" hose end spray wash soap intended for washing windows--and it worked well (I still used a brush on an extension rod to scrub the panels).

    Water spots are from hard water--The do make hose end mineral filters for rinsing cars. Not cheap.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #11
    Re: Cleaning PV panels...

    don't worry about it bill as this is far from the first time somebody else got credit for what i've said or it got repeated later in a thread with my saying it totally ignored.
    from niel, the invisible guy.:cry::roll::p
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  • dwh
    dwh Solar Expert Posts: 1,341 ✭✭✭
    #12
    Re: Cleaning PV panels...
    BilljustBill wrote: »
    I know they don't have the time and manpower to wash and spot free dry all those cars.

    Actually, they do. It's a legitimate job category:

    "Lot Attendant
    Our service department is seeking lot attendants to wash and detail cars. The right candidate must have a good driving record and be available to work alternating weekends."

    http://www.galpin.com/Employment-Opportunities/
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  • Jburgess
    Jburgess Solar Expert Posts: 130 ✭✭✭
    #13
    Re: Cleaning PV panels...

    I got a ad in the mail today for a company that washes solar panels for an intro price of $60. I doubt the extra production would exceed the cost. I'll just wait for rain.
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