Solar Fridge/cooler

higginshiggins Solar Expert Posts: 56 ✭✭✭✭
I'm trying to build a basic fridge/cooler for my shed outside.,most likely i would use a metal box buried in the ground with removable top or cover.During the day i'm thinking of connecting a small DC fan directly powered by a small /medium sized solar panel and for night time i was going to add a temperature sensor with relay to switch over the power from my battery to the fan at preset temperature.It doesn't have to be the best efficiency but i would like some feedback or suggestions as to whether it would work well,what power requirements should i consider or the fan and solar panel,would i need to use any other principles such as insulation etc;Thanks,


  • mike95490mike95490 Solar Expert Posts: 8,868 ✭✭✭✭✭
    Re: Solar Fridge/cooler

    If buried in the cool earth, all a fan is going to do, is blow warm air into it.
    There are "Clay Jar" fridges, use something like a large unglazed flower pot, where evaporating water cools the interior. Not too good in humid areas though.

    The way to use solar, simply, is with a Thermoelectric Module, which cools on one side, and hot on the other, powered by a solar panel, just need a fan on the hot side, and it works when the sun shines. Not efficient, but a neat gadget.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    gen: ,

  • john pjohn p Solar Expert Posts: 814 ✭✭✭
    Re: Solar Fridge/cooler

    The big problem with Thermoelectric Module is that they use almost constant power . You need a 60w one to keep a small very well insulated box at temp about 25degc (45deg f) below ambient under perfect conditions thats 5a on 12v. so if you have solar isolation 5hrs you woud need a panel about 300w (2x150w) and about 100ahr battery as minimum.
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