Alternative Energy

[paul iossi]

check with michael @ mobilehomestead.com, he has an amazing amount of info.

[Jerry Campbell]

Hi Smitty,
Alternative Energy, no matter what kind is very expensive, BUT, if you are going to or are living in your bus and you want to live away from the power grid then spend as much as you can. It is an investment and you can't lose your money. Since I bought my solar panels 5 years ago the price has almost doubled.
How much you need depends entirely on your lifestyle.
Spend some time studying and you'll spend less. The internet is the source of all knowledge, good and bad.
It took me about 6 months to figure out what I needed and then another month to figure out where to buy.
I just installed a wind generator this winter. It works in the wind we have but I don't know how well because I didn't have the money for an amp guage for it before we left for the south. You can't do everything at once.
Good luck
Jerry

Here's another link
http://www.cirkits.com/solar/solarlinks.html

[attachment=0]12_31_07.JPG[/attachment]

[SeanF]

Previous posts have covered a lot of territory, so I'll only add a little:

See the link in my signature for our conversion details. We full-time in our bus, and I work from it 5 days a week, doing computer programming. So as you can imagine, building a sufficiently-sized, reliable power system is important to us. I think you can do it for $5k; ours was around $4k.
The following is all IMO, YMMV etc.
1. First step is to determine your needs, using your current electric bill, and/or a "Kill-a-watt" meter. Determine what your total daily electrical needs will be, adding a margin for additional stuff you'll tack on later (it always happens). Then decide how much autonomy (i.e., no sunshine or wind for electrical generation) you'll want. That will determine your battery bank size. You don't really want to discharge your batteries too deeply, or they will wear out more quickly.
2. Once you know your battery bank size, you'll want to research the solar insolation at your intended place(s) of living. Obviously you'll get more solar energy in the summer, and less in the winter, with the lower sun angle, and shorter days. Use late December as your design criteria when calculating the amount of sun you'll be able to use for solar input. There are many sources for determining how much wind you'll see on a regular basis. Use Google to search on terms like NREL, wind maps, etc. The wind turbine manufacturers have output curves that will tell you how much energy is generated at certain wind speeds. It is NOT a linear relationship, more exponential.
3. Once you have your solar/wind inputs figured out, you can size the wires, disconnects, fuses, charge controllers, etc.
4. You'll also have to decide how much (if any) of your electrical loads will be AC, and how many DC. There is a compelling argument for inverting ALL of your power and running all AC loads. It all depends (like everything else in a conversion).
5. If you are worried about the rare occurences when the sun won't shine and the wind won't blow for several days in a row, it may make more sense to get a small generator for seeing you through those rare times, rather than grossly over-sizing your panel array and battery bank.

There are lots of resources for learning all of this. The Solar Living Sourcebook has good basic info, even though it is also a catalog for buying their stuff, so caveat emptor and all that. A good book is "Photovoltaics: Design & Installation Manual" by SEI, if you can find a used copy, cool ($60 new). If you can swing it, and it's available, a course at a community college can be very beneficial. Text book is one thing, but interaction with people with real world experience is another.

Good luck, hope this helps.
Sean

[SeanF]

Hi Smitty-

Regarding inverting DC to AC and lossses, etc: Yes, there is a loss when inverting DC to AC, and oddly (at least to me), the process is more efficient when inverting MORE power. Anyway, the downside to keeping everything DC is that the DC wires have to be larger, DC appliances tend to be more expensive & less available, DC lighting is definitely more expensive, etc. It is also more complicated to have wiring and outlets of both kind throughout the bus.
There may be a breakpoint when the 10-15% loss (or whatever it is) through inverting is acceptable over the additional costs & labor of dealing with both AC and DC wiring.

Thanks for the comments about our bus. One comment on the deck: We love it, but I'd definitely make it lighter if doing it over again. Trex is great stuff for a lot of reasons, but it is heavy.

HTH
Sean

[SeanF]

I don't know about them specifically, but IIRC they are a reputable brand.

Charging info (and lots of other info) at their site (LINK).

Just a quick look around shows them as 212 AH, and selling for over $400 each. $200 seems too good to be true. I'd do some tests (see the link) before buying. Having been stored that long without any charge can't have been good for them.

Good luck
Sean

[Jerry Campbell]

I don't know about those batteries, But sitting batteries is not a good thing. Buy one charge it and test it first.
Batteries are the weak link in an electrical system. You can only use 50% of their charge and Good ones treated right last only about 10 years. If you buy used ones you'll get even less. If you can, Buy the biggest 6 volt batteries you can move by hand. That's my thought.
I have 1680 Amps, 8 L16H 420 amp 6 volt.
About 1000 lbs.
Jerry

[paul iossi]

check popular science and popular mechanics for alternative power projects,IIRC,there have been some good projects for solar heaters and in particular plans for a windplant useing an automotive alternater and hand carved propeller.