Tuesday, August 11, 2009

When Shit Happens

So, I said we'd probably end up with a bucket that was emptied into the existing septic system in the event that we had to find an alternative to our lovely (water wasting) flush toilet.

It seems like such a waste, though, to simply toss all of that wonderful bio-material.

Joseph Jenkins has some great ideas about ways to use what is usually considered waste, and while, in theory, I know that his methods are perfectly safe and a much better option than the septic tank, I haven't made the mental leap to being comfortable with putting human poo on my garden (which is ironic, as I put rabbit poo and chicken poo on the garden without a second though ... anyway :).

The issue, for me, is that I don't have the storage containers, nor do I have room for several 55-gal drums full of ... poo.

But I also think there's a much better use for all of that poo ... and the animal poo ... and, for that matter, kitchen "waste" and yard waste, too.

A while back, I was pretty certain that our septic system could be converted to a methane digester, and while I found some evidence to suggest that a typical suburban septic system does not produce enough methane gas to make it useful as a digester that didn't stop me from exploring some other designs and ideas for making digesters (including the half dozen or so DIY projects I found on YouTube - what a hoot! ;).

What I found were some pretty amazing projects centered around methane digesters, including this one from India, in which they use kitchen scraps to make methane gas, which they use for cooking.

Because garbage in the streets was such a problem there, the digester solved several problems:
1. The digester gave people a use for their vegetable waste so that it didn't end up in the streets attracting flies and vermin.
2. It gave people a (virtually free) renewable, alternative fuel.
3. It provided compost for the urban, rooftop gardens.
4. It provided water for the urban, rooftop gardens.

In short, once the people who had a digester started producing their own fuel, they were also able to grow their own food. It became a closed loop.

It's one of those things that if I had my druthers, we'd have - even right now, when things are still okay - for the same reason that people have been buying solar panels for decades. It's not just about the belief that we may be left in the dark with no options, but also about choosing to live more lightly.

A methane digester would provide fuel - renewable and non-polluting. The fuel produced have a number of uses, including cooking, heating water, and producing electricity (in conjunction with a generator).

But from the perspective of preparing for the worst case scenario, having a methane digester would close one of our dependency gaps.

We could make our own fuel using our own wastes, and the end result is water and compost.

What alternative system would you install if you could?


  1. I've been interested in methane digesters previously. Gavin has posted about them before. The concept is great, for all the reasons you mentioned. What I haven't seen discussed is *how* the methane from said digesters actually gets used. We have a NG stovetop, and I would gladly convert to methane if I could generate my own, and store it safely. It is, after all, a potent greenhouse gas, and I don't want to generate it if I'm unsure how to use it without spilling it into the atmosphere. If you've seen any info how to do this with barrel digesters, I'd love it if you could point me to it.

  2. Kate,

    I don't think most digesters "store" the gas. I haven't seen one that does, anyway. What I've seen are contraptions where the gas is burned off as soon as it comes out.

    But if your digester is to make electricity, I would think it would go straight into a generator, which would produce the electricity, which would be stored in a battery bank - or put back into the grid, like we'd do if we had solar panels and made more electricity than we were using.

    For me, the best use of the methane would be for electricity generation, for the reasons you mention (not wishing to release too much of my "precious" gas into the atmosphere), and also because, while electricty isn't the most efficient method of cooking or heating hot water, if I were using the methane to generate electricity, I would have more options for how to use it - including heating water and cooking. If I were just producing the gas, I'd be limited to what I could do with the open flame.

    Interestingly, after I wrote this piece, I put it in the queue to be published later. Then, we lost power - on a clear, blue day, without explanation ;). It was kind of surreal. I was really thinking about that digester then ;).

  3. I'm very interested in solar energy. It does take a sizable initial investment but would pay for itself over and over again in the long run. You can also sell excess energy back to the grid and get paid by the electric company, not pay them. But who am I kidding I'm interested in ALL types of alternative energy.

    Kentucky Preppers Network

  4. Hi, Matt,

    Me, too! I'm interested in all types of alternative energy ;).

    We've looked into installing a full solar array on our house, and that might, also, be an option, but there is the initial investment, and without a battery back-up, a solar array would be not much use for about half the year here in Maine. We don't get as much sun as other places :), and so due to the initial expense and the ongoing costs associated with maintenance and upkeep, solar wouldn't be my first option where I am.

  5. Well here in North Texas solar would be a good option. I could go for both solar power and solar hot water. Another thing I have wanted to do since moving to this place with the really sunny backyard is build a bbq with a ordinary grill side on the sunny side and an wood (or charcoal) burning oven on the shaded side. My thought was that in the summer I could use the grill as a platform for a solar oven when not being used to grill. In the winter I could use the grill and wood oven. The house stays reasonable in the winter so I wouldn't really need the oven heat in the house and all the mess would stay outside too.

  6. Woolysheep - I like the idea of a backyard bbq with a wood or "cob" oven, too. I'm still trying to convince Deus Ex Machina to help me build an outdoor "kitchen", but the question for us is not *if* it should be done, but where to put it. I like the front yard, but it would be on the leach bed, which means if we ever had to do anything with the septic system, we might lose the entire structure. But there are no gardens and no animals (except the dog on a tie-down) in that area, and it's horribly underutilized.

    If you build your outdoor space, I'd love to see pictures ;).