woodgeek wrote:For Earthships, IIRC, the goal is to achieve close to 100% passive solar heating and natural cooling, at minimum cost, through high thermal mass, earth tempering and large amounts of direct solar gain. The designs only seem to work well in certain climates, and are very unconventional in appearance.
The goal for the various Earthship buildings is more than just heating and cooling. They collect, store, and filter rainwater which supplies 100% of domestic water. They use a manufactured wetland/garden in the greenhouse that cleans greywater for reuse in toilets and which also grows food. Water is heated with solar thermal - 100% in the US south, about 80% in northern areas with propane on-demand back-up. Electricity is 100% PV - and since electricity demand is orders of magnitude smaller than 'conventional' housing, 2000W of PV is all that's needed. Finally, the designs work in all areas of the world below about ±60° latitude - as demonstrated by buildings in Tierra Del Fuego, all over the US, including upstate NY and Wyoming, three Canadian provinces, Baja California, the Philippines, E Africa, W Europe...etc. etc. These buildings have the lowest embodied energy tally of any other option and are carbon negative from the first day they're occupied.
woodgeek wrote:So, what is the difference then....its all in bets on the future. IF you are a doomer, and think society will collapse to 19th century tech...then an Earthship is your way to go.
I find your assessment interesting. I've been to the Earthship HQ in Taos, have rented a building there, read everything Solar Survival/Earthship has published, have talked with folks in various parts of the world living in these buildings, and have helped build and retrofit a pair of Earthships in Texas. None of the folks are 'doomers'. In fact, the majority of folks attracted to these buildings are interested in disconnecting from the 19th century tech that sometimes provides water, sewer, and electricity. Many of the folks in the US are building these to save money. New, the price per square foot is on par with housing in the ares in which they're built - but once built, the only utility bill is to top-up the propane tank which feeds the backup water heater, the cooking stove, and gas clothes dryer - and that runs about $200. That's $200 per year.
TL;DR - carbon negative; crazy-low bills; uniform temperature in the house without any tech whatsoever winter or summer; absolutely unaffected by state governors feeding the on-grid folks leaded water (Flint), or no water (Detroit); and no utility outages when someone cuts a water line with a backhoe or when storms, drunk drivers, or abnormal heat or cold take down the power grid. In other words - comfort and resilience. Priceless.