Interesting. What zone are you? How cold does it get?

Assuming it's cold-cold in the winter- you'll need a serious solar panel to generate enough heat to keep it defrosted/active. Those are serious expensive- although I hear they sell cheap versions at Canadian Tire and Battery.

A better approach may be to build a mini greenhouse with discarded windows (keep an eye out- people throw them out, or ask a window installer) for the top, and styrofoam sheet insulation for the sides. Build the pile all at once after the first frost. make sure it gets some air, but not enough to cool it that much. An adjustable damper seems wise. You can use this box as a hot frame for seedlings in the spring- or even early winter if the compost is generating heat as well.

If the solar gain from the sunlight doesn't do it- then I suspect that the solar panel and heater wires would do even less.

The other option is to build a really big pile- 6x6' and as long as you can manage, and hope for the best.

Since external heat is not what causes a compost pile to heat up all you need do is keep the pile from cooling down enough to stop the bacteria from working. Some good insulation would do that, although maybe, possibly heated water flowing through a concrete pad might aid some.

Scotty,

The main goal, I would think, would be to keep the microherd going so they can keep the pile active. In essence, you have to feed the compost and not just keep it warm. By providing heat, the compost will stay warm, but to keep it decomposing, your little army has to remain active in there. (Getting repetitive here...)

Anyhow, I compost throughout the winter here in Nova Scotia. Mind you, I certainly don't have the extreme cold and dry winter weather you have in Alberta. Having been in Edmonton for 3 weeks in February I know what you folks have to endure - those -40C can be wicked.

My best winter piles were walled by bales of hay/straw from the north winds. The main items going into these piles were used coffee grounds - I collect about 250 lbs per week - seaweed, and shredded leaves. Even with spells of -25C, the piles would remain active. Nothing was added during the week to let the piles regain activity. Everything added on the weekends if the temperatures outside were above -10C. Most times the temperature in the piles was between +35C to +40C, although sometimes it would go higher.

Needless to say, the worms were happy to have a home and ample food during this time.

Scotty

Your question about solar power being used to keep a compost pile viable during a Northern Alberta (zone 2?) winter is interesting.

I know you have lots of sunshine during the winter. But how many hours of daylight do you have in Dec - Feb?

I seem to remember that in Edmonton during the winter the sunrise was at about 9:00 AM and sunset was around 4:30. And when you get up to Yellowknife there is no daylight at all in late Dec. Of course, the flip side of your location is that you can play golf until 11PM+ at night during the summer.

With such a short period of daylight, the solar idea might be "iffy" How about a small wing turbine to power your compost heater? Seems to me you have no shortage of wind day or night during the winter...eh? (grin)

I live about 1900 kilometers SE of you in Iowa and my compost pile is an ice cube Dec thru Feb. I just let my pile hibernate during the winter.

Good luck with your idea and please file a report if you try to keep your pile going next winter.

Tiffy--I'm curious. Did you use -40C on purpose? -40 is my favorite extreme temperature, and whenever I use it, I ALWAYS make sure I specify C or F.

Here is a link that might be useful: -40

bpgreen,

I always specify C or F even if the two might be the same, which in this case they are. Force of habit since I grew up with the F scale and then they went and changed it on me when my brain cells were starting to slow down. Sucks big time!

So, yes, I did use it intentionally while two more gray hairs were popping out. And, yes, Edmonton is that cold in February, but I'm sure you are aware of that. :O) As a Canadian from the east, I did not realize it was until I was sent there to work for three weeks during such a month. Talk about a wake-up call!!