can I have a small heater being powered by solar power and or wind?

I live in Scotland and I have a small greenhouse on my balcony, as the winter is coming and is already quite cold I was hoping it could be a way to have a small heater powered by solar power or wind power. 
It doesn't need to put out high heat, just enough to bring the temperature so my chilli plants don't die.

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pjfsdias (author) 1 month ago

My problem is not CO2 creation that I am worried about. Is the energy spent on the heating system.

I also forgot to say that the small greenhouse is plastic and can't have any flame near by. that's why I was looking for something electric but protected.

Toga_Dan1 month ago

a greenhouse is a way to turn solar into heat. perhaps insulating is away to make it more efficient. Try a double thickness of plastic. more of the Heat that comes in will stay in.

iceng1 month ago

Energy spent is out of your control.. Only cost, efficiency and distribution are under your direction. Obviously there needs to be an energy storage medium from thermal bricks to chemical batteries and an emergency back up system because solar and wind energy is highly transitory...

rickharris1 month ago

Your cheapest option in the Uk is to buy a paraffin greenhouse heater. Cost very little to run and works fine, with the bonus that it feeds the plants CO2.

Direct solar to thermal
https://en.wikipedia.org/wiki/Solar_thermal_energy

is a more efficient way to turn sunlight into heat, than is solar to electricity to drive an electric heater. It is more efficient by a huge factor, something like 4 to 8, for the same sunlight.

Direct solar to thermal is cheaper too, and moreover a greenhouse essentialy already is a solar to thermal device.

https://en.wikipedia.org/wiki/Passive_solar_buildi...

If it absoultely has to be solar, my suggestion is to make the greenhouse more black on the inside, and better insulated. Some thermal mass might help too, for to help smooth out the temperature variation between day and night.

If you have any way of getting more sun through your greenhouse windows, like maybe some giant mirrors or something, or maybe moving the house to a different lattitude (Ha! ;-)) that could help too.

Also I don't think wind power will be much help for making heat, unless you have an absolutely huge amount of wind.

I guess you need it warm over night too?
If not:
Try a "black box".
Simply put it is a flat and big box with a glass panel on top, all well insulated.
The sun heat the insides and some ducts on the top and bottom allow for the heat exchage as warm air travels up.

For wind and solar I think it is best to opts for something using the least power power possible.
That means starting with good insulation of your green house.
There are heating pads and lines available for the use in reptile enclosures.
Similar to an electric blanket they provide heating even in soil.
Downside is most use mains power and not 12 or 24V.
To get riliable heating from wind and solar you need batteries and usuall lost of them.

A friend of mine is in an area with often severe morning frost and he loves to start his greens very early in the season.
His greenhouse has a footprint of about 5x6m and is 2.5m heigh.
For the cold months he fills the sides with straw to go up on the windows till about 50cm above ground.
This keeps the worst of the cold from the surrounding ground from penetrating into the green house.
The actual heating is done when required and maybe not in the way you might expect.
He uses two brake drums from an old car sitting on some bricks in the middle of the greenhouse.
Axle hole on the bottom is welded shut, top is partially covered by a piece of tin.
If heating is required he uses a single briquette (the big ones for oven use) that he started in his fireplace and puts in between the two brake drums.
Burns for 4 to 8 hours depending on how much of the hole is covered and gives enough heat to keep the frost out.
Since your winters are much colder you might have to use something bigger allowing the use of two bricks at a time.

+1

And since plants prefer CO2 Paulo does not need to worry about depleting the oxygen :-)