Jean Pain (1930–1981) was a French innovator who developed a compost-based bioenergy system that produced 100% of his energy needs on his small holding.  He heated water to 60 degrees celsius at a rate of 4 litres a minute which he used for washing and heating through coils in the pile.  He also distilled enough methane to run an electricity generator, cooking elements, and power his 2CV truck.

If you have not heard of Jean Pain and his interesting compost systems then I recommend you watch these short videos below

A compost mound of tiny brushwood pieces (3 metres high and 6 across) was made of tree limbs and pulverized underbrush.  Pain spent considerable attention developing prototypes of machines required to macerate small tree trunks and limbs; one of these, a tractor-driven model, was awarded fourth prize in the 1978 Grenoble Agricultural Fair.  The 50 tonnes of compost was then mounded over a steel tank with a capacity of 4 cubic metres. This tank was 3/4 full of the same compost (importantly- finished compost!), which had first been steeped in water for 2 months. The hermetically sealed tank was connected by tubing to 24 truck tyre inner tubes, banked nearby for the methane gas to collect. The gas was distilled by being washed through small stones in water and compressed.  Pain estimated that 10 kilos of brushwood would supply the gas equivalent of a litre of petrol.

It took about 90 days to produce 500 cubic metres of gas - enough to keep two ovens and three burner stoves going for a year. The methane-fueled combustion engine drove a generator that produced 100W of electricity. This charged an accumulative battery which stored the current, providing all the light needed for the household.

Hot water was generated through 200 metres of pipe buried inside the compost mound. The pipe was wrapped around the methane generator with an inlet for cold water and an outlet for hot. The heat from the decomposing mass produced 4 litres per minute of hot water heated to 60 degrees Celsius - enough to satisfy the central heating, bathroom and kitchen requirements.

The compost heap continued fermenting for nearly 18 months, after which time the installation is dismantled, with the humus being used to mulch soils, and a new compost system is set up at once to assure a continuous supply of hot water.

This seems like a truly regenerative solution, based on resource creation rather than green wash solutions reliant on destructive hidden industries elsewhere, eg, solar panels that rely on dubious mining practices to pull together resources from "developing" countries.  But why is nobody doing this today?  We can heat water with these piles, and have done many times, but producing biogas as Jean Pain does here seems to be elusive.  Certainly we have found no record of people powering cars since!  We decided to pay Jean Pains nephew and technical collaborator, Etienne Bonvallet,  a visit.... So it seems clear, modern economy along with its seemingly abundant supply of fossil fuel makes this option seem less practical.  The main thing we learnt from Etienne was the dangers involved with high pressure gas!  The car seen in the popular videos did indeed work, but the experiment was abandoned very quickly when they realized how dangerous what they were doing was.  Etienne is now much more focused on producing the highest quality chippers for creating agricultural compost based on Jean Pains work, which is still not comprehensively understood by agronomists.

I have long had a desire to recreate the scenario presented in the videos here, but with a more complete sense of the process and the considerations after talking with Etienne see new limitations.  It is still possible to produce low pressure gas for cooking, etc, but more modern biogas systems seem more effective at this.  Jean Pain was interested in his model as it was a closed loop.

Whilst the idealism of the situation in the videos may not be fully realistic or practical, I am still impressed with the results of using Jean Pain composts and it still seems an efficient way to make farm scale compost combined with water heating for many farm situations.  Perhaps gas is one of those things best dealt with on a slightly larger scale, a community scale, where safety procedures and production can be monitored in a safe and effective way. It has been of great interest to hear and learn a lot more about what is still a little known set of practices, and I am excited to keep exploring and researching modern applications of this pioneering work.