Solar Panels: What Do I Really Need in a Photovoltaic System for RV Electricity?

How many solar panels do you really need on your RV? I don't know. Everyone is different. Two couples that have identical RV's, traveling together to the same places, doing the same things may have different needs.

Some people will never be satisfied with a solar system. The system needs to be monitored and you need to adjust your daily behavior according to how the sun shines. Some people think they are too important to do that. Though it is possible, it is highly impractical to run air conditioning with a solar system. Some people will not live without it.

When we started with solar panels, we really wanted to make it work. Our modest set up worked for us for 359 days without any outside electricity. We did not plug into shore power during that time.

We added to and changed our original photovoltaic system to fit our needs. Most well designed systems are easily expanded. Right now, in the RV we are in today, (we have three RV's) that original system would work great. Even with the same two people, it would be lacking on the two other RV's that we have.

It will make a lot of difference where you are at, and what time of year it is, as to how much a system will put out. At our home base in Alaska, with nearly 24 hours of sun in part of the summer, and about 4 hours of daylight in the winter, there is a tremendous difference without moving the rig a single inch. Tilting your panels can greatly increase their output, but if you fall off your roof while tilting them it may hinder you from using your RV during your extended stay in the hospital.

When I talk about a system I assume it has these components to do these functions:

• Solar panels to create the DC current from the sun.

• A regulator or controller, to vary the charge sent to the batteries and turn the charge off so the batteries don't over charge.

• Extra batteries to store the DC current.

• An inverter to change the DC current to common AC current. You don't have to have an inverter, but it makes life so much easier if you do.

A solar system can start small and be built or expanded as you need or can afford it. If you start small, always use wire that can handle what you may expand to, and get a controller that will handle the extra amperage. Running new wire is a pain in the butt. Replacing a perfectly good, but too small, controller is somewhat aggravating and an added expense. When you mount the panels, anticipate where you might put additional panels. Be aware that they may be a different physical size. Moving panels is also aggravating and leaves you with an extra set of holes to seal.

There are many calculators online and in books to help you inventory your electrical usage and to help you determine how much output you can expect from a set up you may be considering. You may want to change some of your electrical appliances, tools, and gadgets to some that are more efficient. You may need to learn to turn off lights, TV's, and computers when not in use. You shouldn't run those strings of patio lights.

Phantom loads are a big concern while using an inverter, solar panels, and batteries. Inverters use or lose a certain amount of electricity converting DC current to AC current. If it is running just to power the clock on the microwave, keep the TV, satellite dish, or computer on ready mode, power that cell phone charger left plugged in, or an electric razor or toothbrush you'll be wasting your precious electricity. While all these may be acceptable uses for the pure convenience of it while plugged into shore power, they are extravagant while on solar.

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Editor's note: My husband, Bob Nilles, wrote this article. Solar power fascinated him when he installed our first photovoltaic system on our travel trailer, and lo and behold, without being hooked up to a regular electrical connection, we had electricity to power our lights, tools, and appliances. He now has a better understanding of how it works, but the end result -- electricity from the sun -- still amazes him.



Go to the page indexing Bob's articles.

Go to the page that indexes the other articles about tools and equipment we use for full-time RV living.

Go to the RV Life and Travel blog from this article about solar panels and choosing and using a photovoltaic electrical system.