My compost pile is cooking at a 144 degrees F

[BrotherBuzz]

Friday, I harvested and sifted 96 gallons of black gold from last years compost pile in preparation for the fall rush. Saturday, I did some early pruning and threw the debris into the pile. Today, I stuck a thermometer in and was surprised at how fast it took off.

Damn, I got to thinking that I need to harness this heat source and supplement my house needs. Hot water or heat, any crazy Rube Goldberg ideas on how to capture and put this energy to use? :)

[xxqqqzme]

1. check the archives of Mother Earth News.

http://www.motherearthnews.com/

There has to be an article about harnessing compost power from the last 30+ years.

Congrats on a wildly successful compost. I remember cold winter mornings, looking out the kitchen window and seeing steam rising from our black gold hill.

[BrotherBuzz]

2. Thanks, there are many articles on harnessing the heat

Jean Pain, a frog, has done a lot of the legwork on this concept. :thumbsup:

[Dead_Parrot]

3. Of the top of my head...

IIRC, this idea was kicked around here for a while, but it was worked out you'd need an industrial size heap to generate anything meaningful for home use.

But you can certainly use it for propagating seeds - Fill a tub with a load of composting material, add a thin layer of potting compost (with seeds of your choice) and cover with a cloche if needed, and the heat from the compost will get your early crops off to a flying start... I think a minimum of 9"x9"x9" of the warm brown stuff was recommended. :)

[BrotherBuzz]

4. Sadly, you're correct on the economy of scale

Nevertheless, I will dream about the time I have the land and equipment to run a system to beat the power company. Heck, an endless supply of manure, wood chips, a scoop-loader tractor, and a thousand dollars for materials and fuel, and I could save a couple of hundred dollars on my power bill. I'm just stubborn and stupid enough to attempt it as a matter of principle. :)

I don't think a minimum of 9"x9"x9" would ever reach critical mass ;), however the same dimensions in feet would work. 5 ton piles seem to be the minimum mass to work with, larger piles would last longer, attain higher temperatures, and would push through cold snaps to assure an entire season of heat.

Oh, on heating potting sheds, I heard someone was able to do it by raising rabbits (body temperature 103º F) in an insulated shed. He heated his potting shed and received fine manure, to boot. I understand they taste like four legged chickens, too.

[Dogmudgeon]

5. The pile itself needs that heat

If you come up with a way to utilize it, the pile won't ferment right, and the entire enterprise will be for naught. (If anyone has expertise in the thermodynamics of composting and knows differently, though, please post.)

Even the amount of methane composting generates isn't enough for household use (IIRC). On the other hand, composting has so much value in itself that you probably shouldn't worry about issues like "waste heat".

On the other hand, if you were a farmer or were raising, say, pigs, you could process organic wastes and have enough methane and heat to get some use of them.

--p!