The Earthship sits in the middle of 20 acres of "wasteland" in fertile farm country. It is considered "waste" because it is rolling, partially wooded, and has a creek and drainage ditch cutting across it. From a factory-farm perspective it is garbage.
On site we keep a Jersey cow, a pig or two, chickens, and turkeys. We have a large garden and grow all of our own grain, and most, but not all, of our feed grain following post-organic principles.
On the property is a large 1904 farmhouse that we use in the summer and for groups and gatherings. This farm house, however, was built during a time of heavy long-johns, and abundant, cheap coal and is terribly inefficient for winters in this climate.
We want to live sustainably, using as few resources as possible (renewable and certainly non-renewable), while maintaining what we feel is an adequate and comfortable quality of life. Understanding that we all draw a line, but there is always the matter of where it is drawn, we are trying to practice what we preach.
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The earthship utilizes a number of energy technologies including passive solar siting (we get direct sunshine through the windows and onto the floor from sunrise until about 5 pm in November), a thermal umbrella for 6 months passive heat storage, insulated low-e windows, attached greenhouses, exstensive plantings for winter wind protecton and snow drop, super-insulated walls and roof, solar water heating, rainwater collection and storage, and dual voltage electrical wiring with photo-voltaic generation.
Siting:
The house is set into a southeast facing hillside of glacial clay. (We're making tiles from some of the clay dug from the house site and some of these tiles will go back into the house.) This takes full advantage of what winter sun is available at our Minnesota latitude. We do lose a little evening sun but this is offset by the protection from the west and northwest winter winds.
Thermal Umbrella:
Utilizes the average temperature found 25 feet below the surface (much like a heat pump but with no moving parts), by insulating the (dry) soil that abuts the house walls from the seasonal temperature fluctuations. An added advantage is the storage of waste heat generated by lighting, appliances and, well, us.
Water Systems:
We have the typical farm water well, but have a 12v pump, photovoltaic panel, and deep-cycle battery to pump water. The roof, greenhouses, and thermal umbrella are designed as catchments for rainwater, and we have a couple of cisterns for storage. Salvaged parabolic mirrors serve to heat copper pipe for hot water (stored in a pair of insulated, recycled comercial water heaters) with a tankless on-demand water heater as backup.
Greenhouses:
We are using greenhouses for both plant propagation and thermal gain. There will ultimately be three greenhouses, one just southwest of the core unit that is used for thermal gain and a seriously extended growing season, one above the thermal umbrella that will be used for thermal gain in winter and and seedling propagation in the early spring, and a third that will sit above the first and be primarily for solar gain for the first greenhouse, turning it into a year-round hot-house for full year crops and tropicals (citrus in Minnesota?) We hope to use a passive methane generation system (livestock manure: carbon neutral) to heat (supplemental) the lower greenhouse.
Weather Plantings:
There is an established grove of trees and shrubs that creates a near-perfect wind break and snowdrop well to the north and west of the building. Obviously, forestry is an important part of "maintenance" for the site and house. (We also utilize the old European "twig" heating technology, collecting dry sticks from the forest floor, for a substantial part of our Tuli Kivi style heat source. Sticks are carbon neutral.)
Super-insulationOver the concrete roof panels we put 6" of foil-wrapped styrofoam insulation and cast an additional 3 ½ inches of concrete over that. This serves as sealant and rainwater catchment.
Dual Voltage:
While some of our appliances run on 110v AC bought from the grid, many run on the 12v DC system we have built and installed. Powered by photovoltaic panels, the electricity is stored in a series of deep-cycle batteries and is used for lighting, forced air circulation (for example, warm air from the greenhouse on sunny winter days, and outside combustion air for the wood stove), our CD player and amplifier/speakers, laptops, etc. Our state does not yet force utilities to buy excess consumer generated electricity and, of course, they choose not to do so (if you live in Minnesota write your state legislator) so it is not yet cost effective to build in excess generating capability. We hope to put up a wind generator eventually.
Composting toilet:
The state requires a complete septic system for greywater, so we have one, but we built a fiberglass Clivis knock-off for human waste which is composted and then plowed into the field land. The system uses a 12v computer fan and small PV panel for ventilation.
Food Production:
We grow a variety of small grains, both for nutritonal variety, but also as a traditional hedge against climate problems ("bad years"). On a "good" year wheat does well here, but in a "dry" year the barley and rye out-perform the wheat and oats. Our livestock gets all of our excess regardless of the flavor. We planted 375 Marquette wine grape vines this year and will begin making our own wine as soon as the vinyard is in serious production. We have just under ¼ acre in vegetable production, selling our excess at the local farmer's market (not particularly profitable but it helps support the community). We grow black walnuts and raspberries in quantity, and are nurturing a young orchard of apples, cherries, plums, pears, and even a greenhouse sheltered peach and a sweet cherry tree. We have a jersey cow and make cheese, and we try to raise a pig or two on the garden surplus each summer. Our chickens and turkeys are truly free range with unfettered access to, well, the whole world if they want it.
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Other Notes:
We use salvaged and recycled materials when we can (and pray for more responsible product design in the future). We run our pickup truck on E85 (closer than gas to carbon neutral, not as good as bio-diesel).
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Think about this: Coal and Oil were nature's way of sequestering carbon at a time when there was too much in the atmosphere. Oops! When we get a handle on this, what's left will probably be something like limestone, or chalk. Would't it be elegant to pave your factory floor with marble made from your own carbon emissions? Beats turning grandma into a diamond.
