Once you arrive at your destination, the amount of energy consumed by an RV is far less than that of your home. By design, the RV is an environmentally friendly house. You have water-saving devices like a 6- or 10-gallon water heater, compared to a 40- or 100-gallon water heater in your home. There is a water-saving toilet, and you aren’t watering the lawn or using the dishwasher when you are RVing. According to the American Water Works Association, the average U.S. residence uses about 110 gallons of water a day. I would venture to say when we use our RV, as a family, we probably use less than 40 gallons a day.
On the electric side of energy consumption, your RV uses less than your home too, even when you are plugged into a campground electrical service. It is more efficient to heat and cool the RV simply because of the amount of space we are heating and/or cooling compared to our homes. Another reason is that your RV has many devices that operate on 12V DC power, while home devices require 120V AC. Even if your home uses LP gas for heating, cooking, and hot water, your home on wheels uses much less propane to do the same thing.
If you are really interested in reducing the carbon footprint left behind in your RV and going green, you can start by looking at renewable energy. America depends on fossil fuels—oil, natural gas, coal—for nearly everything. Fossil fuels are not renewable and cause pollution whenever they are burned. Renewable energy, on the other hand, can never be used up, and the clean sources of such energy—solar, hydrogen—don't pollute either.
For RVers the most convenient and logical renewable energy source is the sun. Through solar panels, batteries, and inverters, we can harness this abundant, free, renewable energy for our RV.
Solar RV 101
A typical solar system for an RV consists of solar panels, batteries, some type of charge controller, and an inverter. The way it works is the solar panels capture the sun's energy and produce direct current (DC) electricity. This captured power is stored in the RV's auxiliary batteries. A charge controller makes sure the RV batteries are fully charged, but not overcharged. The power inverter converts the DC power stored in the batteries to alternating current (AC) to be used by the RV's appliances. Many of the inverters found in RVs today are inverter/chargers. What this means is they are inverters, battery chargers, and a transfer switch all in one.
Now the question is how green do you want to go? The size of the solar panels, batteries, and inverter you need depends on how much power you want in your RV. You don't want to purchase a larger system than you need. That would cost more money and weigh more. But you also don't want a system that is too small for how you need to use it.
Inverters are rated in watts and come in a variety of sizes and power ranges, anywhere from 75 watts to 3,000. When you purchase an inverter, the output capacity must be capable of operating the loads that will be placed on it.