Notes from Windward: #64

Installing a gas line for the dining hall.

getting ready to produce and use our own natural gas

the gas and data lines in place

     Up to now, we've run our large kitchen stove on propane, and that's worked well enough, but our goal is to construct a bio-digester that will produce our own natural gas, and use that to operate the kitchen systems.

     In addition to the stove, we have an on-demand water heater to generate the bulk of the hot water used in the kitchen, and that will heat water way more efficiently than an electric water heater can. Most of the cabins have small water heaters that are okay for a quick shower, but the shower in the dining hall's bathroom is designed to allow a number of folks to shower longer since on-demand heaters never run out of hot water.

     While we had the track hoe on site digging the trench for the non-potable water line, we had him cut in a trench behind the dining hall so that we could install a line to bring gas from where the digester will be located to the dining hall. For a variety of reasons, it's good to store fuel away from buildings, and now before the north side of the dining hall gets backfilled is an excellent time to lay the line.

     You'll notice that in addition to the black iron pipe that will carry the gas, we're also laying in a run of electrical conduit that will allow us to pull a run of Cat 5 twisted pair from the dining hall to the methane digester, thereby allowing us to continuously monitor a variety of reaction perameters without having to physically visit the digester. Many's the time we've wished we had that capacity in place in order to monitor other systems such as the potable water; and so we're building that capability into the new construction.

     The gas line is black pipe instead of galvanized since gas isn't as corrosive as water is, but there's an added advantage to consistently using black for gas and galvanized for water in that when you uncover a pipe, you know what you're dealing with. In a similar vein, we use only white PVC for plastic water lines, and only gray PVC for electical conduit. It's remarkable how easy it is to forget that some line is running right where you want to dig, and when you find a "mystery" line, it's good to have some idea of what it is you've uncovered.

Same thing, looking north

     The gas line runs between the dining hall and a 500 gallon propane tank that we'll use to store the methan produced by our digester. Actually, it will also store some propane, since production and consumption are rarely in balance, and if we run short on methane on any given day, the propane stored in the tank will take up the slack.

     That's a good example of how our goal is self-reliance rather than self-sufficiency. We want to have as many viable options as we can reasonably undertake to bring on line, rather than irrevocably committing ourselves to using only what we produce on-site. In order for a program of this size to be sustainable, you have to be efficient, and sometimes that means taking advantage of bargains.

     We are committed to distancing ourselves from the use of fossil fuels, or for that matter any energy source that we have to purchase, but that's a goal which has to be worked toward gradually in order to prevent disruptions in other parts of the program. Conservation involves producing more than you consume, and as long as we're able to stay in the plus side of the energy ledger, we're happy to take advantage of a wide range of resources depending on what works best on any given day.

     In short, our approach is one based more on practicality than on convenience. We eventually do get to convenience by good design and effective planning, not by throwing money at a problem, but rather by careful design and a willingness to start small and tinker with a system until we get it the way we want.

     Our first goal was to get the organization up and running, and now that we're well established, we're working on steadily shifting towards a more self-reliant form of operating. It's a slow and gradual way to work, but it's also the path which is most sure of producing a viable outcome.

     We're still not clear on how we're going to design our digester, whether a vertical batch design will work better for us than a horizontal continuous processor, but those sorts of questions will sort themselves out in time. For now, we know that however we generate the gas, we're going to need a safe and secure way to get it to the dining hall. By doing the part of the task that's at hand, we whittle it down to a manageable size.

laying the safety tape in the trench

     After the black pipe was assembled and pressure tested, it was time to start burying it. The first step in that process involves covering the pipe and conduit with about nine inches of dirt, and packing that down.

     The next step is to run a length of warning tape on top of the pipe. The purpose of this is that if you're ever digging and come across yellow or red warning tape . . .


     It's easy to forget where you laid a line, and that's true even if you were the one who did the digging. In Windward's case, many of our lines were installed by either Mike or Bob1, and since both of them have passed on, there's only a general guess as to where some of those lines run.

     Once the warning tape is buried, then it's a matter of filling in the ditch and packing down the dirt. The easiest way to do that in this sort of situation is to run back and forth along the ditch with one of the big tires on the backhoe. The distrubed earth is still going to settle somewhat come next winter, but then it's just a matter of topping off the depression with a bit of gravel.

     Constructing our own natural gas facility is going to be an interesting challenge, and sure to throw a curve or two our way. Still, at least one part of the project is "in the ground" and done. And so the project moves forward another step.

Notes From Windward - Index - Vol. 64