Sub Urban Agriculture - Pilot Study

COMPOST WATER HEATING The use of green agricultural waste for composting is a fairly well established practice in most farms, providing a free source of fertiliser for the next season’s crops. The process of composting however also releases a lot of heat, in a typical garden compost it can quickly reach temperatures of up to 40 degrees, should this heat be put to better use in a small district heating scheme, the energy demands of the agricultural accomodation and potentially the neighbouring suburban houses could be drastically reduced.

With the waste from the fields typically matching the yields, composting on a large scale provides even better results, reaching tempearatures of over 60 degreees and could provide a significant quantity of hot water for both heating and use in the dwellings.

Research into compost water heating is fairly comprehensive, just never been attempted on a large scale involving more than one dwelling. Researcher Jean Pain trialled a number of techniques for this in the 1980s, proving it was feasible to heat water for central heating purposes to provide for his own home by submerging rubber tubing at specific centres on layers inside a compost heap.

If this technique could be applied in a more static way to the inside chamber of a large scale compost container then the compost bin can be constantly filled up from the top and emptied from the base, ensuring a continuous supply of material to the compost, minmal interruption to the important fertliser production process as well as a constant supply of heated water.