This definitely fits the category of other, but I have researched and have been thinking for quite some time about this possibility...heating my home by compost heat.
I grew up on a farm, and while we tried everything in the world to stop silage from heating up and resulting in spoilage, in digging into the pile, inevitably it was quite warm almost to the point of putting your hand in it hurt...and this was the depth of winter! I always thought it was a waste of heat. It was not until I got sheep and a house that is fully radiant heated that I thought it might actually work.
My entire house is slab on grade with radiant heat with a PLC mixing valve system. It does not matter how the main boiler loop is provided heat...coal boiler, propane boiler, solar heat, or compost heat...as long as it is between 100-150 degrees the propane boiler won't come on. So with compost heat, I would simply be taking the heat composting in a pile and bring it into my house via pex tubing.
I think I got all the major components to do it. Since I live on a hill with a 6% grade, and I have a 53 foot insulated box trailer for a tractor trailer set up, I would make a cut in my hillside, burying it into the ground with all but the back end covered. I would fortify the roof, then cover that too with soil. That would insulate the trailer quite well. Then I would loop the roof of the trailer with pex tubing probably pretty tightly, like 6 inches on center. That would then be piped to the main boiler loop with a big circulator to pump the water. The trailer body would then be charged with a mixture of waste silage/sheep manure/and wood chips to get a "hot compost" in the fall of the year. As the heat from the composting action rose, it would heat the water in the pex and be transferred to my concrete slab in my house.
Since the cost would only be for the pex (1000 feet), a big circulator, and to dig a hole deep enough for the trailer, I wonder if it would not be worth it?