Horse manure heating!

[Netty]

Hi this is my first post. I think I have it in the right section, given that its a bit of a hare-brained idea of mine

I have been thinking for a number of years of trying to tap off some of the heat generated from my muck heap - I have 10 horses, so no shortage of poo here

Over this time, I have been having conversations with my uncle and cousin who set up our (oil) central heating system, about whether or not this may work (in theory anyway). We have decided that I need to be having a min temp of 50 degrees c to run this, without risking damaging our current system.

Last week, it was -4 out there and my muck heap is hitting temps of over 80!

So, what with the price of oil now being over 70p a litre, our rapidly depleting level in the tank and not being able to get the oil suppliers to even pick up their phone, let alone get an order on its way out to us, I thought perhaps now may be the time to try

I read on line of someone who has done something similar to heat water, and I also know of a nutty farmer who has literally done just that and heaped his cow poo at the back of his house, but I only know of him via someone who knows him, who knows someone else....you get the picture.

The *problems* I foresee, are 1) not being able to get a big enough pile out there (I'm thinking of heaping it in the coal bunker - I have a B&B and didn't think the guests would be too impressed with a heap of horse poo at the back of the house , but I was also hoping that by keeping it in something like that, may help to retain some heat that would normally be lost when the heap is exposed and help counteract some of the heat lost caused by me drawing the heat off) to make this work and 2) by drawing off the heat, it may interfere with the fermentation process and stop it heating up. (OK there are other concerns, but these are the main ones)

I joined to see if any of you know of anyone else that has tried something similar? I'd be interested in your thoughts even if it is just to 

Cheers

Annette

[Billy]

Perhaps you could utilise a ground source heat pump and put the pipes in the heap.  I know they they get hot but I wonder how sustainable it would be.

Sounds a brilliant idea to me.  Does the heap give off methane as it rots?

billy.

 

[A.L.]

Hello Netty

try googling for Jean Pain or go here - en.wikipedia.org/wiki/Jean_Pain

[dhaslam]

Not a hope of it working.   I borrowed a horse last year  to keep the grass  down  and collected the manure for the garden.  It was stored in a compost bin for a while  but the heat  produced is negligible.  Ten times as many horses and all year round as well  would get you some heat  but nothing like enough to make a difference.

If you have  a long south facing fence  you could construct a  very large solar collector that could  replace heating oil completely and with a lot less effort.    

  

[martin]

Top notch first post! I've long thought that this is one of the most under-exploited areas in renewables, and will be very interested at the response you get, and obviously the results of any experiments.
 I think I've somewhere mentioned the Victorian Kitchen Garden series that talk of the manure "hot beds" used in Victorian times to grow crops - so it certainly works*!

*I think you need a fairly large mass of it for it to work, and the right mix of poo and straw - I remember as a child watching in wonderment at the vast steaming heaps of it on what would nowadays be called an "organic" nursery - I think that ideally you'd look at getting heat from the heap, and the methane!

[Netty]

Thanks for the replies and the welcome guys. I came across Jean pain recently, very interesting! I think though that it was the methane (yes, it does give off methane Billy, but the thought of capturing that scares me a little - sounds a bit "explosive" Actually I think the Met use it for heating, from their police horses) that he used mainly for the heating.

dhaslam, no unfortunately we have no south facing areas, we are completely surrounded by mountains and therefore get very little light full stop.

I have a feeling size really does matter in this instance . I know (through building muck heaps for 30 years), that it needs to be a certain size for it to generate enough heat so that it rots as fast as you add to it and I think it may have to be a fair size, but that said, my small experimental heaps aren't doing too badly out there.

As for the straw mix etc. Hmm, the people that were heating their water mixed it with wood chip/shavings (4:1 if I remember rightly) and a tree surgeon friend of mine has recently told me of a collage that is using heaps of woodchips to do just this. I had a woodchip pile earlier in the year (a surface for my riding arena, heaped up before we managed to get it in there) and sure enough, it heated up rapidly, but not as hot as my piles are atm. Interestingly, its the straw mix that is reaching the highest temps. I dont know why. The only thing I can think of is that straw rots quicker than shavings, so maybe its more of a quick flash of heat, and perhaps the wood mix would be a slower but steadier release. I dont know, I'm no scientist


I'm planning on using a coil of hep20 to run through it, I read somewhere that the coils need to be spaced, but I'm not sure how I'll be able to do that in the confines of a bunker  I'm trying to keep the cost to a minimum atm, so that we haven't lost too much if it doesn't work....but of course it will even if it may need some tweaking to get us there and feeling a bit better than we are atm

Guess its going to be a suck it and see situation, though not literally I hasten to add

[martin]

John Seymour published plans for an "effluence digester" in the 70's which was designed just to extract methane - he used a simple water-seal "gasometer" design made from 50 gallon barrels. If I remember  right, he just had a "flame check" device on the output pipe

[Netty]

I take it back! Jean Pain did indeed, it seems, heat his house from heat extracted from his compost heap....So maybe its not such a daft idea afterall... Just need to convince my husband that having a "construction" that big in our back garden is acceptable

[Justme]

Make sure you think about how you will recover the pipe at the end of the heaps usefulness.

I would think about having a solid pad that you can easily "muck" out with the pipes embedded in it.

Your controlls will need to be set so that they dont draw to much heat out & stall the cycle.

[Netty]

Your controlls will need to be set so that they dont draw to much heat out & stall the cycle.

How do I know how much is too much though? Other than trying it and seeing what works and what doesn't?

[EccentricAnomaly]

Watch the output temperature.  Assuming the water going into the heap is noticeably cooler than the heap (otherwise, what's the point?) and the heat exchange into the pipe is reasonably effective then the water coming out should be just a little cooler than the heap.  If you know what its "static" temperature is, e.g., when you just start pumping water through, then you just need to keep it only a few degrees cooler than that.  If it gets much cooler then it's time to slow the water down to take less heat.

[renewablejohn]

I have used an IBC container in the past for creating a hot bed. I coiled ordinary hose pipe around the IBC container and then wrapped insulation around the IBC container and made an insulated lid. Worked for approx 3 months at which point you had very good compost. First time we tried we got a slimey mess as liquid collected in the bottom. Problem solved by leaving the drain cock undone.

[Netty]

Watch the output temperature.  Assuming the water going into the heap is noticeably cooler than the heap (otherwise, what's the point?) and the heat exchange into the pipe is reasonably effective then the water coming out should be just a little cooler than the heap.  If you know what its "static" temperature is, e.g., when you just start pumping water through, then you just need to keep it only a few degrees cooler than that.  If it gets much cooler then it's time to slow the water down to take less heat.

A-ha. Now that makes sense. Thanks.

[Netty]

I have used an IBC container in the past for creating a hot bed. I coiled ordinary hose pipe around the IBC container and then wrapped insulation around the IBC container and made an insulated lid. Worked for approx 3 months at which point you had very good compost. First time we tried we got a slimey mess as liquid collected in the bottom. Problem solved by leaving the drain cock undone.

Sorry - IBC?

[guydewdney]

Intermediate Bulk Container