The use of solar panels on RVs is increasing. Whether this is due to people wanting to live more “greenly” than in the past or they simply want to go off the grid (where power isn’t readily available), more and more RVers are adding RV solar panels to their rigs. Whatever the reason, RV solar panels are a great idea! Solar panels have two main uses: they can trickle charge house batteries and they can be a source of primary electrical power.
Primary Electrical Power
Anything inside your RV that can be run off of a battery can also be run off of a solar panel system. A complete solar panel system can provide primary power to your entire RV, making it a great addition to your home away from home. To do this you must install several solar panels with corresponding gear, often sold as a solar panel kit. This kit creates, monitors, and regulates your RV’s power to ensure that there is enough power for routine operation of your RV’s systems.
How Much Solar Power Do You Need?
Solar panels can capture about 10 amps of power. This can charge a normal RV battery. You can expect a 10 amp RV solar panel to offer a hundred watts in most cases. The maximum power that can be derived from the sun is around 1 kilowatt per square meter. Factor in cloudy days, an undesirable angle of the sunlight onto the panel, the temperature of the panel, and other factors beyond your control, and the usable power from a solar panel is only a fraction of the energy that the sun deposits on the panel. When all is said and done, modern solar panels provide about 60 watts per square meter, which is only about 6% of the sun’s energy that hit the panel. When you measure up the space you have available on your roof or elsewhere, you may find it difficult to capture the power required to run your RV’s house systems completely off of solar power. For a large motorhome, you might need 500 to 800 watts of power. That’s about 10 to 15 square meters of RV space filled with solar panels.
Increased Solar Power
Some large solar panel systems can produce a staggering 320 watts of solar power since they’re designed to capture sunlight, store it, and then convert it into energy as needed in order to power all the modern conveniences your RV offers for comfortable living in the great outdoors. For every 100 watts of solar power you will probably pay around $200. This price includes the panels but not the charge controllers or inverters.
Solar Power System Components
There are three types of solar panels, categorized by how each individual cell on the solar panel is constructed.
Monocrystalline solar panels feature cells that are thin wafers of a pure silicon crystal.
Polycrystalline solar panels feature cells that are made of silicon that is melted and then poured into a mold.
Amorphous solar panels feature cells that are made of a thin layer of silicon attached to a backing material.
Amorphous cells are the least expensive type of solar panel. While they are better at collecting power from the sun on cloudy days, they’re not as efficient at collecting energy as the other two types of cells. Most solar panels made for powering and charging are constructed of either mono or poly cells. However panels that are made for trickle charging are not.
Solar Charge Controller
The charge controller, sometimes called a charge regulator, is the command center for your RV’s solar system. It manages and regulates the power (both current and voltage) coming from the solar panels to prevent your batteries from becoming overcharged. Solar charge controllers can read and adjust battery voltage, optimize power flow, calculate solar panel production, keep the RV solar system running efficiently, and keep your batteries from overcharging. The solar charge controller makes sure your solar panel system runs smoothly.
Maximum Power Point Tracking
Maximum power point tracking (MPPT) has improved the way charge controllers interact with the different RV solar components. An MPPT controller is an electronic DC to DC converter that converts the higher DC output from the solar panels to a lower DC voltage needed to charge your RV’s batteries. If you use a regular charge controller, you will lose a lot of power if there is a poor match between the output on the solar panel and the current charge on your battery. The MPPT charge controller on the other hand will constantly compare the output on the panel with the battery charge state, optimizing the voltage to get the most amps into the battery. An MPPT charge controller is a must if you are serious about building a quality RV solar setup.
Digital Monitoring Unit
The quality (and related cost) of your solar panel system setup will determine your ability to monitor it. Some systems use indicator lights, while others simply list the voltage. By using a digital monitoring unit you will be able to read the volts, amps, and cumulative amp hours of your solar panel system and you’ll be on top of your RV’s solar energy.
For a snug, secure, fit, use high-quality mounting hardware. You have a few choices when it comes to mounting your solar panels. You can mount them temporarily or permanently. If you choose to mount them temporarily, this gives you the option of positioning them to face the sun when you move locations. You can also mount your panels either flat or with some tilt brackets.
Campers in the Central and Southern U.S. generally can get by on a smaller amount of solar power as compared to those in more northern states. Southern areas generally experience more hours of sun every day and fewer rainy, cloudy days than northern states. Cloudy days can still transfer a charge to a solar panel, but the charge won’t be as great. If you know the average of daily sunlight for an area that you’re traveling to, you can narrow down which solar system is best for you.
Time of Year
Time of year and its usual sunlight amount is an important factor for selecting a solar system. Short days with frequent clouds and unpredictable sun exposure can drastically cut down on the amount of power a solar system can deliver for battery recharging. Needless to say, you get the most bang for your buck in the spring and summer months from your RV solar panels.
Solar panels are a smart RV investment. You’ll feel good about helping the environment and you’ll love the money you save over the long haul.