Anyone Combing PV with Solar hot water?

it seems to me that my panels produce enough heat that I could easily place a passive solar water heating system (like that used for a pool) under the panels to absorb some of this 'excess' heat. (ground mounted system btw)

Anyone tried this?


  • BB.
    BB. Super Moderators, Administrators Posts: 33,478 admin
    Re: Anyone Combing PV with Solar hot water?

    I believe "Solar Guppy" posted about running those simple solar thermal pool collectors under his solar panels for heating his pool in Florida--and found that it somewhat works (could not find the post--and I may be faulty in my recollections--has happened before)...

    My guess, is you have enough area to install the solar thermal collectors in open sun--You will get more/better heat, and you need fewer of the solar thermal panels (because they are not shaded).

    In the end, you will not be able to "cool" your solar PV panels (cool PV panels generate more power--but it would be very difficult to "thermally bond" the pool collectors to the PV collectors), the costs for more piping/collectors for larger thermal collectors (because they are shaded), and maintenance issues (if you have a water leak in the pool collector, you would have to unmount the PV collectors/wiring to get at the leak to fix/replace component).

    Might make sense if you have very little access to "good sun" and need to share the space between solar PV and solar thermal--otherwise, probably not worth it (in my humble opinion).

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: Anyone Combing PV with Solar hot water?

    I have a 3.5kw array about 4" over my solar thermal array for the pool. The PV panels I would guess-i-mate reducing by ~60% the energy that gets to the thermal panels based on the reduction in gains I now see in the water temperatures.

    I would NOT recommend this setup and I'm now losing about 3 months of the year of pool use due to the reduction in heating. One of these days I plan to move or add some collectors to get the heat gain back where it was for the pool, on that famous to do list!