Electrical Power TA

Sources

Solar Panels

The most obvious and conventional source of power. 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.

Stirling Engine

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?

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.

Grid

Reliability and if I reach a point that I'm producing excess power, I can sell it back to the grid (I think).

Wind

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 solution

1. Start with grid power
2. Bring home-brew solar panels online (using discount solar cells)
3. Bring solar water online
4. Move towards the Stirling hybrid solution

Notes

Solar

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

http://www.instructables.com/id/DIY-Solar-panels-for-RV-or-off-grid/

Stirling

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.

Assorted

Instructible on solar hot water. Good details. http://www.instructables.com/id/Solar-Water-Heater-Part-1-The-Collector/