Electrical Power TA
The most obvious (and conventional) source of power is solar panels. While they provide a known path, they have several major drawbacks. Their cost is of significant concern and so is their environmental impact. Their lifespan is somewhat limited (20 yrs) and I will get very little power in the winter. A major factor here however, is that the price, lifespan and manufacturing techniques may change significantly in the next 2-4 years.
The key alternative that I am currently considering is integrating my power and hot water systems and using a Stirling engine to generate power. This system would have some maintenance costs, but with upkeep would have a nearly unlimited lifespan (with some maintenance). It is easily supplemented (having a coil come out of the tank that I can apply heat to). I also enjoy that this design is something I can understand and maintain myself (and possibly build myself). Presuming I have enough hot water, this should also allow me to generate power even when the sun is down (by storing solar energy as hot water). A trade off is that I put all my eggs (hot water, heat and electricity) in one basket, this is advantageous because it would allow me to direct my focus, but if one goes out, they all go out. The big question in all of this though is feasibility - can I get enough solar hot water to keep the system running? Will the hot water provide enough energy to run the Stirling engine? Can I buy or build a Stirling engine to meet these requirements?
The last consideration is a generator. This would only be considered as a temporary solution, but in order to get into the Earthship quickly, it may be worthwhile to consider simply buying a generator (diesel?) and using that to get moved in, then focusing on alternative energy.
One more note, I should include some wind energy, it probably won't contribute a lot, but there's a good chance it will help even things out and contribute energy when it's needed most. There are some simple designs using PVC and a car alternator.
Hybrid solutions: Almost by definition, these are innumerable, but a few options stick out. 1) Start with a generator a few hundred watts of solar panels for building and getting moved in. Then transition to a more long-term solution. 2) Start with .5-1Kw of PV then build in a more advanced Stirling system
Buying solar cells on ebay seems like a good route. Any thing above 1w/$ seems good, but large batches go as high as 2w/$. Buy tabbing wire to make it easy on yourself.Garage / Shop
I am considering setting up a separate small shed like building as a shop as well as water/power management point. The idea would be to have large solar collectors for hot water in front and a large hot water tank inside (this could be a constructed tank, or I could simply dig a hole, insulate it and line it pond liner). Inside the shop there would be the engine and alternate heat source.
The alternate heat source would presumably be a rocket stove. A coil of pipe would come out of the hot water tank and wrap around the chimney (or inside the chimney), when the water temperature fell below a certain point, I could fire up the rocket stove, turn on the pump and the water would heat up. Once the water reached its upper bound, the stove and pump would be shut off. Eventually, this process could be automated.
The engine would be Stirling engine. When the battery charge falls below a certain point, the pumps would kick in. One pump would move water from the hot water tank through a coil running under the Stirling engine (the hot plate). Another pump would move water over the cold plate, this would continue until the batteries are recharged.
Research Needed: Material temperatures - Ideally, the hot water tank could handle water all the way up to boiling, but to accomplish this the insulation, liner and pumps would all have to be rated to 212F.