This past week, I had the pleasure of attending the Sustain Jefferson (Jefferson County, Wisconsin, United States) meeting. Our “info-tainment” section of the meeting would be a presentation by Greg David, a founding member of the group, he was recently honored as a Badger Bioneer.
I videotaped his presentation, so that anyone not able to attend would be able to see it.
Greg is a pretty amazing guy. For years, he has been working on converting a small piece of agricultural land to a permaculture heaven. Instead of “farming” in the conventional fashion, he uses plantings that help RESTORE the ecology. For example, while the typical farm is wide open fields, 20 years ago Greg planted a windbreak of evergreen trees on the north and west sides of the property. Other plants and animals on the property are protected from the wind, and a mix of fields, prairies, and trees greatly increases the diversity of habitat.
But that’s just the start. Greg has continued to work in alternative construction methods, run a CSA (Community Supported Agriculture), and has the biggest asparagus patch of anyone I know.
Greg has also been working on building SOCIAL capitol. Much of his work is not just about ecology, but getting people to work together. From Co-ops to general socialization, we are able to build relationships that make us all more valuable and able to accomplish more than we would on our own. One example is the Community Supported Energy workgroup.
The CSE is roughy based on the CSA – people all put in some work, and everyone gets back out of it. The focus of the CSE is energy-producing projects (all of which fit in well with Peak Oil theory, Transition Towns, etc.) These have included Gasifiers, Rocket Stoves, Solar Hot Water Panel, Methane production, low-tech boilers, and how to design and build them. I can think of one member in particular who has the greatest smile in the world after learning to weld from working on DIY energy projects.
Some days, work on these projects is as simple as standing around and getting a lot of talking done. Other times, you can’t hear yourself over all the angle grinders and metal work. But at all times, the members are building an informal organization of interdependence, learning new skills, and exchanging ideas.
Yesterday, I stopped over for the “Gasifier Work Day”. The current project is the “Bountiful Bowel” – a low-tech methane digester.
If you aren’t familiar with methane digesters, here’s the quick once-over. Put manure in one end. Make sure it’s the right temperature. Jiggle, shake, stir as needed. Methane gas comes out the other end. The gas can then be burned as fuel for cooking, heating, or running an engine (such as to power an electrical generator.) Of course it’s more complicated than that, but that’s where the fun is, figuring out all the details.
To start with, the “Bountiful Bowel” digester is a more or less a large trough, about 4′ high, 4′ across, and 16′ long, insulated, and covered. Inside, a clear plastic tube bag lays in plain water. Manure is added to the bag from the one end. On the opposite is a valve for removing the methane gas. The bag is in the water to keep the manure slurry at the right temperature for the microorganisms to do their work, breaking down the waste, and making it into a useful product.
The entire “Bowel” is set on top of a layer of strawbales, with additional bales surrounding the sides. The insulated cover is foam, but some additional insulation (ideally natural/renewable) would be good to have on top. As part of our discussion, we came up with the idea of creating a large quilt with loose straw as the filler. We would literally blanket the top of the tank.
The next challenge with the “Bowel” is to keep the water in the tank warm enough – especially in Wisconsin winters in an unheated workshop. That means getting heat from somewhere into that water. Our concept is to use some sort of large, liquid, thermal storage, which could be cycled into the Bountiful Bowel as needed. We did have some PEX tubing around, one section of which was 110′ long. Seems like enough for a heat exchanger. The PEX could be stretched out inside the methane digester tank, with hot water cycling through it to transfer heat to the tank.
Again, the details are the fun part. How do you get it to lay flat? How do you keep the temperature from dropping TOO much from one end to the other? We laid out the PEX in a flattened helix – sort of an out-and-back Olympic Rings shape. Both ends of the tubing were on the one end, making it easy to attach the pump, make connections etc. Since the tubing doubles back on itself, the average heat output of the heat exchanger with be the same through the whole length of the tank.
To get the tubing to lay properly, we stretched it out and zip-tied the looks evenly spaced out. The zip-ties were angled so that they would point away from the internal plastic bag, and that’s a fairly thin material. Poking holes in a bag of manure would not be a good thing! (Ick!)
That’s about as far as we got yesterday afternoon. Projects like the “Bountiful Bowel” are continuing. It’s a learn-as-you-go project, combining planning and construction. The next step is to get a large watertight container that we can insulate to hold the heated water.
People like Greg David are leading the way, not just restoring the ecology that we need, but also helping us all come together to learn, create, and motivate. Please enjoy watching the video at the top of this post. I know that you will find it inspiring.
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