Jean Pain was a French visionary who established a compost based bioenergy system that provided all his energy needs. For washing and heating he heated water to 60 degrees celsius at a rate of 4 litres a minute. Through these experiments he concluded that a circular coil or series of concentric circular coils was the best design for extracting heat from a compost consistent with ease of constructing and deconstructing the pile. He also distilled enough methane to power an electricity generator, cooking elements, and run his truck. Come to be known as the Jean Pain Method this process of energy production through the composting of waste materials has been exported throughout the world.
The idea is to produce and store methane generated from the compost pile but in order to do so, the temperature must be kept fairly low. The micro-organisms in the compost generate a lot of heat trying to break down that matter and running water through the system will keep the temperature low enough for the methane-producers to be happy. The side effect of this cooling system is hot water coming out the other end. Put simply this system starts with a carefully constructed, large pile of biomass. The biomass heats up as it goes through the composting process. Pipes running through the pile pick up heat which can be used for domestic water heating and/or space heating. Some schemes simultaneously collect bio-gas, which can be used for cooking fuel or even running a vehicle or generator.
Jean Pain with Compost Heap and Water Bearing Hose
The devastation of the Mediterranean forest by fire was of chief concern to Pain. With the introduction of grazing animals and cereal cropping thousands of years ago a terminal course of de-humification of soils was set in motion. He experimented with the production of compost from brushwood thinnings around France’s parched southern forest. Pain demonstrated by progressive applications of this compost and mulching technique that high quality vegetables could be grown without irrigation in these dry soils. He further speculated that the forest itself could he regenerated by selective use of the same material.
Pain pointed the way to making productive the expanse of scrub and dry forest of the sub-temperate and sub-tropic regions, whose soils were exhausted by the ware and tare caused by the natural course of modernity. Motivated by a profound hindsight into the inevitable depletion of natural resources, he mobilised the production of industrial grade energy from a simple yet abundant earth resource. Its main attraction is the promise of a carbon neutral way of generating useful amounts of heat over long periods of time. Most importantly this energy production system provides an economical if unique alternative to the modern world’s dependence on fossil fuels.
Simply the technology works because Compost heats up. Reaching 60°C (140°F), a heap of this volume would ferment for up to 18 months and provide through a plastic coil embedded in the pile heated water for domestic use throughout its production life. Pain heated his five room 100 m2 house and provided hot water for its occupants from a 50 ton pile for six months, and a 12 ton pile maintained that output for a full 18 months. It takes some work to build one of the structured compost piles and set up the heat extraction plumbing, but then you may be able to get useful heating from
the pile for an entire heating season. The efficiency is claimed to be of the same order as burning the biomass — maybe even a little better. In many cases, the biomass can be material that would just be left to rot in place. The mixture should be well watered as a dry mix will not work so well. It is in the harnessing of the heat given off in the core of the wheelie bin that makes the process work.
The Jean Pain Method implements two basic biochemistries: in the presence of oxygen, cellulose and lignins in woody material break down to humus; and suspended in water, anaerobically, and held at 36°C (97°F) the same woody material will support bacteria that produce methane gas. Interestingly, only slightly different to the process in the production of wood alcohol.
Methane—natural gas—is an industrial fuel. It can provide combustion energy for cooking and space heating, but it can also run motors. Convenience in transport and for vehicle use dictates compressing the gas, but this too is possible with methane-generated electricity and simple compressors.