This video covers the history of compost heat recovery and the state of the art science, by Gaelen Brown of Living Web Farms.
“Here is a revolutionary approach for heating rooms and generating hot water. Author Gaelan Brown has worked with engineers and compost scientists to refine methods of composting that can heat greenhouses, barns, buildings, and hot water, all without combustion. It seems almost too good to be true: make high-value organic compost while generating reliable combustion-free heat. But it works, and this book is your practical introduction.”
Better Than a Rocket Stove Greenhouse Heat shows a good low tech option using heat from decomposing leaves.
Previous story about Jean Pain who pioneered the use of compost for supplying households energy needs.