My little hot-water from composting wood-chips experiment is yeilding promising results. I am getting 100-degree water with a flow rate just under one gallon per minute, (from 48-degree well-water). The temperature holds steady at 100 degrees, even when we've had extended periods of freezing weather.

The water was as high as 118-degrees just after we built it, and the piles of wood-chips that were sitting in the yard before we made the mound got up to 130 degrees. I believe the higher heat was the result of the finely-shredded materials in the piles that were composting at a faster rate. Most of the material is small chips, vs shreds.
100-degree-moundInsulated-Mound
Jean Pain was able to get 140-degree water, and he claimed it was essential to "shred" the wood chips to speed up the bacterial process. I just used soaked, compacted wood chips instead to save time, (I guess I'm one of those dumb Americans who thinks he can get by the easy way), but I would say that is why my "mound" is only 100 degrees.

So, what am I going to do with this heat-resource? It's not quite hot enough to use for domestic hot water or a radiant floor heating system, but there's still a lot of thermal value in having a constant supply of 100-degree water. So my plan is to simply get an on-demand hot water heater (the kind used in tandem with solar hot water systems), and then turn my existing heater/tank into a simple storage tank. Then I'll get a cheap circulation pump, and circulate water from the tank, through the mound and back into the tank to constantly keep the tank full of 100-degree water.

Then, whenever I use domestic hot water, some cool water from my well will be pulled into the tank, but the water leaving the tank and going into the on-demand heater will be 100 degrees (give or take), so my on-demand heater will only have to heat the water +20 degrees (instead of +75 degrees). So my propane costs for hot water should go down by close to 75%.

Saving 75% of your hot water heating bill is about the best-case scenario for most solar hot water systems, so if I can acheive that with my "Brown Mound," that will be great. However, the mound that we're planning for my parents house in the spring will be made with shredded chips, hopefully to get a steady, 24-7 supply of 120+ degree hot water for their hot-tub.

Again I want to thank everyone who helped us build this and offer my support, advice, help for anyone who wants to roll up their sleeves and build their own "Mound of Pain" or "Brown Mound" or "Makeupyourownname Mound." Special thanks to www.sunwoodsystems.com and Whitney Tree Service in Waitsfield, along with the www.CarbonShredders.org and Valley Futures Network www.valleyfutures.net who helped me round up teams of people to build this.