Solar panels are becoming much cheaper as a source of energy for your motorhome or travel trailer. But how much does a solar set up cost? Well, that depends on what your electrical needs are when you're camping without hookups.
There are three components to a solar setup...the actual solar panel(s), the charge controller, and the battery(ies).
Let's start with the basics. If you are camping without plugging in, you will need electricity for the electronics of your fridge, your lights in the evening, and perhaps your furnace or hot water heater. All of these items will have to run off your 12v DC house battery system. Yes, your fridge, furnace, and hot water tank all use propane, but you still need a 12v DC source of power to run the electronics for those units.
So, you have at least one 12v battery already in your unit that supplies this power. Some people can get by with a single 60W or 80W solar panel in order to recharge this battery the next day if you are conservative with your usage, and you have a sunny sky.
If you shop around, you can buy a single 80W panel for under $400. I was lucky and bought a new 80W panel from ebay for just over $200...it pays to shop for a deal!
The general rule of thumb is that you need approximately 80W of solar for every battery. This is not written in stone though, because if you are in an area that doesn't get a lot of sun, you may need more panels to make up for that. Or, if you get 6 or 7 good hours of sun every day, you may get enough power from one 80W panel to charge two batteries.
The neat thing about solar panels is that you can start with a fairly basic setup, and add to it if you feel the basic setup isn't enough. That's what we did...we bought two 80W panels, and found that although 160W was good, we didn't want to feel limited and decided that if we could get a deal on another 80W panel, we would add to our setup.
Having said that, buying anything less than a 60W panel is pretty much useless. I am fairly sure that if you buy one of these little 15W or 18W panels, it will not do what you're wanting it to do.
