Forum home› The potting shed
This Forum will close on Wednesday 27 March, 2024. Please refer to the announcement on the Discussions page for further detail.

solar powered greenhouse heater

dawnlricketts78721dawnlricketts78721 Posts: 3
in The potting shed
Hi All,

I have been trying to find an 'off-grid' solar powered heating system for my greenhouse and potting shed for the winter.  I can buy the kit but it seems this wont produce sufficient power for a heater (unless I can fit 10 x 1m panels on the shed roof apparently!).

Trying to avoid oil heaters and running electric is a bit of a problem.

Has anyone purchased or built a system that works?


Posts

  • steephillsteephill Posts: 2,841
    As Scotty says "Ye cannae beat the laws o' physics!" It takes the same amount of energy to maintain a given temperature no matter your fuel source so there isn't a magic alternative. Are you just trying to have a frost free greenhouse and shed or do you need a higher temperature for exotics?
  • nick615nick615 Posts: 1,487
    If, as Steephill says, you simply want to keep the frost off, a stack of plastic water containers (filled and painted matt black) will absorb enough solar warmth during the day to produce that marginal degree or two you require. Pineapples for Boxing Day may be a different proposition.
  • robairdmacraignilrobairdmacraignil Posts: 782
    There are people who build greenhouses to be frost free over winter using good insulation and thermal mass like the water containers painted black mentioned already to use the sun's energy even in winter to keep a greenhouse warm. I found this video a good explanation of the practice.

    Happy gardening!

    https://www.youtube.com/user/sustainableveg/videos
  • dawnlricketts78721dawnlricketts78721 Posts: 3
    The dwarf banana plant will be coming in for winter, I do insulate the greenhouse and built a  beer can heater which strangely works quite well  during the daytime but pretty useless once it's nighttime, ideally wanted to have it warm enough to try and get an earlier growing season otherwise it ends up a jungle in there come July 

    Have managed to grow melons and currently growing some loofah (not bad for scotland) but these all need a slightly longer season from what i can tell

    Will definitely give the water idea a try , thank you for all your help 😊 
  • thevictorianthevictorian Posts: 1,279
    A hotbed might be another option if you have the space. There are a few videos on YouTube about it and it's basically a compost heap that provides a good level of heat as the material breaks down.
  • greatnorthernexoticgreatnorthernexotic Posts: 119
    A others have mentioned, it's difficult to produce enough energy through solar panels, especially in winter, to sufficiently heat a greenhouse.

    Insulation and thermal mass are the two strategies. Large bubbled bubble-wrap, covering the glass as well as an extra layer around tender plants works well. Water (black containers) aligned to capture as much of the sun as possible.

    If you have power, a small bar heater is cheap to run if used in conjunction with a thermastat. Mine is set to turn on when the temperature inside my greenhouse drops to 5oC. 

    This video shows the setup in my 4ft by 6ft greenhouse:
    https://www.youtube.com/watch?v=_dWaqgw2_5U

    Growing tropical and desert plants outdoors in West Yorkshire
    INSTAGRAM/ YOUTUBE
  • steephillsteephill Posts: 2,841
    http://www.reuk.co.uk/wordpress/solar/solar-greenhouse-heat-sink/ is another approach.

  • dawnlricketts78721dawnlricketts78721 Posts: 3
    Thank you,  looks like I'm going to be building a heat sink once the greenhouse is a little more empty 
Sign In or Register to comment.