Did you know you can heat your water using a compost pile? Me neither. Compost water heating is fortunately becoming much more well known. Paul Wheaton explains how he used compost to heat water for his shower.
Cornell University discusses the physics of compost heating and explains:
Compost heat is produced as a by-product of the microbial breakdown of organic material. The heat production depends on the size of the pile, its moisture content, aeration, and C/N ratio
A single compost pile can be used to make steaming hot water for over 500 showers!
Cornell: Compost Physics
Rich Soil: Paul Wheaton