Solar Power: How It Works

You know that Solar Power Panels can help you and your RV become "electrically independent," but, how do you know how much power your RV will require?

Wattage Charts
Numerous charts and lists have been published with long lists of appliances and how much power they draw. You are then supposed to add up all the watts, then find out how many hours of sun you get, etc etc. You then usually end up with a figure that says you need 44 panels, 24 batteries, and a 5000 watt inverter.

This is not the best way to go. These charts are OK for rough planning in a larger system, such as a remote home, but RV's are much more limited. Regardless of what the chart formula says, if you don't have room for all of it, it is not much help.

Make An Educated Guess
The best rule of thumb seems to be to make a wild educated guess. Generally, figure about 75 to 120 watts of panel for every 200 AH of house battery (2 golf car type) that you have. If you have a pair of golf cart batteries, or a single 4D or 8D 12-volt battery, a 75- 100 watt panel would be close. Few RV systems use more than 400 watts of panel, and typical is in the 75 to 360 watt range.



Start Small, Then Expand As Needed
Often, the best thing to do is just buy a one or two panel system and see if it gives you enough. It is very easy to add on more later if you need them - and if you don't need them, you've saved a few bucks. If you take that route, make sure you get a charge controller that will handle any extra amps that you might add on later - otherwise you will have to buy an additional controller later. RV solar screens are also an option many people are looking into.

How Much Energy Does My RV Require?
The amount of energy required by your RV depends on how much electricity you used the night before. A 24 foot RV used in the summer can usually get by with 5 amps of input with 200 amps of battery storage. In english, you will need a solar panel about 47" x 21" (120 cm x 53 cm) in size. To be exact you will need to know how much power the electrical devices in your RV consume.

Occasionally, at yard sales or refuse yards, you may locate free solar panels. These may have usable parts, that you can then revitalize again for your use.