Electricity:

I'm planning on using a solar power set up to power my "safe" house, so that's what I'm going to start with.

Batteries:
One of the most important part of the power system. The right type of batteries must be selected. Here's some information I've gathered.

Battery Size: The size of the battery bank required will depend on the storage capacity required, the maximum discharge rate, the maximum charge rate, and the minimum temperature at which the batteries will be used. When designing a power system, all of these factors are looked at, and the one requiring the largest capacity will dictate battery size. Our System Sizing work forms take many of these factors into account. One of the biggest mistakes made by those just starting out is not understanding the relationship between amps and amp-hour requirements of 120 volt AC items versus the effects on their DC low voltage batteries. For example, say you have a 24 volt nominal system powering a load of 3 amps, 120VAC, which has a duty cycle of 4 hours per day. You would have a 12 amp hour load (3A X 4 hrs=12 ah). However, in order to determine the true drain on your batteries you have to divide your nominal battery voltage (24v) into the voltage of the load (120v), which is 5, and then multiply this times your amp hours (12 ah). So in this case the calculation would be 60 amp hours drained from your batteries - not the 12 ah. The easiest way to quickly determine the total battery amp hours required is to first determine total watt-hours required by all loads, and then divide by the nominal DC system voltage. This resulting number will indicate the amount of amp hours needed to operate all loads for a given period. However, additional amp hour capacity would typically be added for more "reserve" capacity or to prevent complete discharge. Using the above example, 3 amps x 120 VAC x 4 hours = 1440 watt-hours divided by 24 VDC battery environment equals 60 amp-hours; the same answer as before, but another way to get it. There are other factors for determining the full extent of the battery drain, such as temperature, start-up factors, etc., but this should help you get a more complete picture on how to size your low DC voltage batteries when powering 120/240 volt loads using an inverter.

Type:
You can use other types of batteries but these are the most abundant and require the least maintenance.
Deep cycle batteries are designed to be repeatedly discharged by as much as 80 percent of their capacity so they are a good choice for power systems. Even though they are designed to withstand deep cycling, these batteries will have a longer life if the cycles are shallower. All lead-acid batteries will fail prematurely if they are not recharged completely after each cycle. Letting a lead-acid battery stay in a discharged condition for many days at a time will cause sulfation of the positive plate and a permanent loss of capacity.

Series wiring:
Series wiring refers to connecting batteries to increase volts, but not amps. If you have two 6 volt batteries like the Trojan L16 rated at 350 amp hours, for example, by connecting the positive terminal of one battery to the negative terminal of the other, then you have series wired the two together. In this case, you now have a 12 volt battery and the rated 350 amps does not change. If you were to series wire four L16's you'd have 24 volts at 350 amps, and so on.

Parallel wiring:
Parallel wiring refers to connecting batteries to increase amps, but not volts. If you have two 6 volt batteries like the Trojan L16 rated at 350 amp hours, for example, by connecting the positive terminal of one battery to the positive terminal of the other, and the same with the negative terminal, then you have parallel wired the two together. In this case, you now have a 6 volt battery and the rated 350 amps increases to 700 amp hours. If you were to series wire four L16's you'd have 24 volts at 350 amps, and then parallel wire these four to the four other that are in series, then you'd have a 24 volt battery at 700 amps.




Solar Panels:
Solar Panels are pretty easy to come by, you can find them just about any where. You just have to be careful with them because if you get the wrong one it'll toast your batteries. Solar panels come in a wide variety of sizes with different volts and amps for each size. If you gather a bunch of small panels you're going to have to wire the panels together. The panels can be wired up in series or parallel just like batteries depending on your application and need. You're going to need a soldering gun or iron, solder and wire to wire them together. Most panels are delicate and will need a protective cover also. You could use an old window and window frame for this. Once wired together you could lay them face down on the glass and duct tape them to the window if needed.

I'll put some schematics together of how to wire up a battery charging system so that you don't over load or drain your batteries.