Showered in compost

All throughout the winter our method for having a wash has been to heat the sauna, twice a week, which at times has seemed like we are slightly pushing the hygiene boundaries, particularly as most days we are doing physical labour. 16 years ago when I first met Dan, he used to have two showers a day! 

But heating the sauna is a fair amount of work in itself as we have never had the time to make enough firewood to have the luxury of just skipping to the wood store and picking a basketful. So to have a wash, we first have to chainsaw some lengths from the pine we scavenged from the site of last summer's forest fire; split them with an axe, then heat the sauna for an hour and a half (which in itself is a very pleasurable ritual). But then, as we have had no hot water system, we have had to boil several pans worth of water on the hob; enough to wash a family of four (and often our friends' family as well who currently live on site) and to throw on the hot stones of the sauna stove. So you can imagine you might settle for having a wash twice a week.

Well, we have no excuse for being smelly any longer! Since last weekend we have been  enjoying steaming hot showers straight from the tap!

With the help of a flashmob of permaculture design graduates from Leeds and their friends from Normandy we constructed a compost water heating system based on the design of Jean Pain, a French innovator, who pioneered the system in the 1970's. By building a large pile with green wood chips or other woody debris that decomposes slowly you can generate enough heat to provide you with up to 18 months of hot water of up to 60 degrees C. 200 metres of plastic pipe that is spiralled inside the mound stores 65 litres of hot water and when drawn, in theory, more should be heated at the rate of 4 litres every minute. 

You don't have to add in any nitrogenous material, but ours is a mixture of wood chip (carbon), the soft outer husks of almonds (carbon) and horse manure (nitrogen). The manure makes it more active, but it may also mean it will decompose faster and bring an end to our hot water supply sooner. 

The mound is a monument of permacultural ingenuity and serendipity on our farm. We wanted to buy a chipper because every year we end up with piles of branches and sticks from pruning the trees. The local custom is to burn them in bonfires, thus sending the carbon off into the atmosphere - we want to put it back into the soil. Not only can you heat your water with it, but wood chip makes fantastic mulch and once defunct as a heater, the mound will be compost, rich in nutrients and with a high capacity for holding water; and we are desperate for organic material in our depleted soil, particularly in the olive grove. 

In terms of serendipity: the chipper was bought collectively with other permie-minded people, who then brought their design course buddies with them and built the compost heating system together with us. Can't get much more permaculture than that! We returned the favour by helping with their almond pruning and the collaboration is rapidly expanding. 

Jean Pain further developed the process to produce methane to run his chipper and tractor with. We may get to that in a few years... In the meantime we are interested to see how long we will actually have hot water for. And when we build the next one, we'll get some higher grade plastic pipe as this one is giving off a strange smell... Kind of barn-like... Which defeats the object of having a wash!