General info

It is possible! With only garden waste and a little help from nature you can heat your house or greenhouse. The Swiss Jean Pain (1930-1981) conceived this technique in 1960 for the first time and received a lot of imitation. Jean Pain Composting is a method to make good compost from woodchips (prune waste). This also generates a lot of heat that can be transferred to water by means of a heat exchanger in the interior of the compost heap. The hot water can then be used in the house (showering, washing, heating) as well as in many alternative applications.


The Termocompost, also known as Biomeiler, consists of a large cylindrical or conical heap , average up to 2,5 m and diameter 3 to 7 m, made up of green and agriculture waste: wood chips from prunings, manure, leaves, grass ...Inside this mound, plastic tubes act as heat exchanger for water heating. A pump allows the circulation of water, which is generally stored in a buffer.


During the aerobic composting process, microorganisms (bacteria, fungi) break down organic matter into compost that is very nutritious for plants. With this conversion a lot of heat is released, because the reactions ongoing are similar to combustion, but they happen more slowly and there is no flame. This means that the environment within the pile i very warm, on average around 55-60 °C, for long 6 to 24 months, depending on size and other factors.


1) The compost obtained after this long process is endowed with important properties, not only nutrients, but also structural; this means that a soil treated with this type of compost recovers fertility, porosity, water retention capacity and several properties. This type of compost also has a good economic value. Furthermore, part of the carbon present in the green waste keeps stored in the compost, thus contributing to the CO2 capture from atmosphere, that helps to diminish the greenhouse effect.

2) Thermal energy from renewable sources, because obtained from biomass. This energy is produced locally and continuously, it can be used for heating domestic (showwring, house heating, swimming pool etc) and non-domestic environments (eg greenhouses).

Thus, two products are obtained from one waste with great valorization and sustainability!


This device is characterized by a low technological level, it can be built independently with a group of friends or a crane, and the components can be easily found on the market and repaired. You will need also enough space in the surroundings of your heat user appliance, because our friend is quite big!


The true value of this technology is the integration of green processes in several fields: renewable energy production, waste management, soil and food quality.

1) Generation of small circular economy streams and valorization of local resources → important benefits in terms of economic, environmental and social resilience of the territories

2) Replacement of fossil fuel with a renewable source for hot water production → economic savings and reduction of atmospheric pollution

3) Reduction of centralized management of green waste → reduction of vehicular traffic, savings from waste management taxes

4) Production of high quality compost → Replacement of synthetic fertilizers, improvement of soil quality (fertility and structural properties, resistance to hydrogeological phenomena), less pollution, higher food quality, CO2 storage

Illustration from Sylvia Machgeels