We understand your passion if you’re like the other estimated 25 million Americans who have also caught the RV bug. It’s hard to beat the freedom of taking to the open road, whether it’s for a weekend jaunt at a nearby campground or a two-week vacation off the grid. Using solar power adds a new dimension with other benefits that may surprise you.
We’ll discuss everything you need to know about using solar to equipping your RV with solar panels. The first question you likely have is how much solar power do I need for my RV? There are several factors that go into answering that question of how much solar power you need. They include:
RV Camping style
Current setup with batteries
Typical energy usage while camping
We’ll discuss one in detail to help you make an informed choice about what you need.
The first thing you need to consider is what is your usual RVing trip.
Do you camp primarily at campgrounds with shore power?
How much is boondocking a part of your camping lifestyle?
Are you jonesing to go to more remote locations in your RV?
Answers to these questions can help you decide whether you need a full-blown solar kit with a battery bank or if you can get by with supplemental power to charge devices like your smartphone or a solar battery.
Also, think about how long your average trip is. Are you a weekend warrior, or are you out for total escape where you forget what day or time it is?
If you are interested in equipping your RV with a solar kit you should check out our post all about it! We pick and review the best ones and also an extensive guide all about the best RV solar kits.
This one is the money question—literally! The more often you camp at campgrounds with shore power, the sooner you’ll recoup your cost of going to solar power for your RV. It’s essential to consider this point when thinking about how much solar power do I need for my RV.
While technology has brought the costs down, solar power still is an investment that requires some serious cash upfront for your RV. Therefore, it makes sense to do the math to make sure it’s right for you and to find out how much you need. The next part of that equation concerns your system and its power grid.
Going solar isn’t simply a matter of installing a few solar panels and calling it a day. It’s more involved than that. To determine what you’ll need, let’s start with what you already have to get a baseline for how much you’ll need to use solar power.
You likely have a battery or battery bank already running the devices and appliances on your RV when you’re not hooked up to shore power. You may even have a generator if you already do a fair amount of dry camping. Then, there’s the alternator on your vehicle, which charges up your battery or batteries.
All of these things are your personal power grid when considering RV solar.
Think about where you want solar power to fit into this equation. Do you want your RVing to be more eco-friendly by reducing your generator use or even eliminating it all together? Do you need something to use during the day when you’re off of shore power and getting power from your batteries alone?
Let’s find out how solar power can work for you.
The place to start when figuring out how much solar power do I need for my RV is with the energy that you use when you camp…
You could break out a calculator and do the math to figure out how much power you’re talking. You’ll also find interactive guides that can add everything up, piece by piece.
Our advice is to skip all of those methods. You can get a ballpark figure much easier without all the rocket science. After all, you don’t need a precise figure. Instead, a range will give you some wiggle room because each camping trip is its unique experience.
There is a simple way to calculate the solar power needs that will help you on your journey toward taking the plunge. It begins with a fully-charged battery or batteries and an excuse to go camping for a few days.
You’ll need to know the amp-hours of your batteries and a means to keep track of your battery voltage level. That’s crucial if you have the lead-acid battery because you shouldn’t let them go below 50 percent to prolong the life of your batteries.
Then, go camping.
Don’t do anything different than you normally do. Make it the typical trip. The catch is that you’re not going to use shore power, your generator, or your vehicle’s alternator to top off your battery or batteries. Instead, you want to find out how long it takes you to get to the 50-percent battery level.
Note the time you start and when you get to that point in hours.
Doing this will give you an idea of how many solar panels you’ll need for your RV. It’s an essential part of the equation. It’ll also give you a taste of going solar without a noisy generator running or the limit of being tied to shore power. You’ll only rely on how much power your batteries can supply.
For example, let’s say you have two 100 amp-hour batteries powering your RV. Your critical level is 100 amp-hours to stay above 50 percent for your batteries. You then find that it takes you four days to get there. Dividing 100 amp-hours by 4 gives you 25 amp-hours per day for how much power you use.
The next step for figuring out how much solar power do I need for my RV is the number of solar panels that you must get to get your batteries charged. A rule-of-thumb is that the typical 100-watt panel will provide about 30 amps per day. In our example, one will get the job done based on how much you used in this scenario.
Another guideline that you can use is to match the total watts of the solar panels with your batteries’ amp-hours. That would mean two panels instead of the one that we calculated. Why is there a difference between how many panels you’ll need with the batteries you have?
The essential thing to understand about any power source is that they are never 100-percent efficient, even RV solar. The same thing applies to solar and even more so when it comes to how much power. That’s because there’s no controlling the weather or the amount of sunlight that the solar panels will get. Other factors include:
You can get an estimate based on the monthly average for your area or where you usually camp. Compare this figure with the hourly power output of the solar panel. For example, if the panel provides 5 amps, and you camp in June when you can plan on six or more hours of sunlight, you’re still getting enough for your daily needs (5 amps times 6 hours equals 30 amps).
However, you also want to have a cushion to cover for those times when your system isn’t working at peak efficiency, which, as we’ve indicated, is rarely if ever. Bear in mind that if the weather isn’t great, the chances are you’re inside of your RV and using more electricity.
We’d also recommend keeping upgrades on the radar. The more you go RVing, the more likely you’ll want to get more toys and the next big thing as the technology advances.
There are some other things to bear in mind when choosing your solar kit that will help provide an excellent guide in making the right choice. You should also think about where you camp and its solar capacity based on topography and climate.
The Southwest enjoys ample days of sunny weather, making it a popular destination. Other parts of the country won’t get reliable sunshine year-round, such as the Pacific Northwest. There’s also the question of winter camping.
Your batteries will discharge quicker in colder temperatures. You’re probably spend more time inside of your RV too, which can add to your energy usage. If you camp frequently during this time of year, you probably should repeat the ballpark test again during the winter. Another option is to use a supplemental source from a generator or shore power to help cover your energy needs.
A good battery is something you can’t neglect. Nothing worse then having your trip halted because of a dead battery. We cover a huge range of the best RV deep cycle batteries in this guide we recently posted.
Now that you have a ballpark estimate of your solar needs, the next step is to put it all together in a solar system. A basic setup consists of four components:
Let’s discuss each one and how it fits into your system.
You have several options when choosing solar panels for RV, based on your energy needs. You can get portable ones that you can store between trips. The advantage of this type is that it gives you more flexibility regarding their placement and thus, the amount of power they can provide.
You can also go with RV solar panels that you install permanently on your RV. The benefit of going this route is that you have a set-it-and-forget-it solution for RV solar. You will find some solar panels for RVs that allow you to tilt them to optimize energy capture per day.
There are also different kinds of RV solar panels. The monocrystalline solar panel consists of one silicon crystal that provides the most efficient way to convert sunlight to energy. The polycrystalline solar panel, on the other hand, has more than one crystal. What is loses in efficiency, it makes up for in cost. We like both types for what they offer.
You’ll also see flexible or thin-film panels. The selling point with this type is aesthetics. If you don’t like the obtrusive looks of a solar panel on your RV, this one is your best option since it will lay flat on the roof. It isn’t as efficient as the previous two. You’ll find that 100 watts is a typical size for a solar panel.
The wattage and the output of your solar panels must be in line with the voltage of your battery. That’s where the solar controller comes into the game. It ensures that your batteries don’t overcharge, which can shorten their life. It’s a vital safeguard when using solar power.
The essential spec on this component is amps. To determine what your system needs, divide the total wattage of your solar panels by the voltage of your battery. The other figure you must know is its input current so that it can handle what it’s receiving from your system.
For example, our 100-watt solar panel with a 12-volt, lead-acid battery is 100 divided by 12, which equals 8.33 amps. You should look for the next amp size up to cover for the inefficiencies of the system and give you some wiggle room.
You’ll see two types of controllers, pulse width modulation (PWM) or maximum power point tracking (MPPT). The latter is the more efficient and more expensive of the two. It’s a better option if you go camping during the winter or if you have higher energy needs. Overall, it is more efficient at managing power, especially after your batteries are charged.
We like the MPPT type because of its energy savings.
Unless you only run DC appliances, you’ll need an inverter to use AC ones with a solar panel. We’d suggest getting one to handle the one requiring the most juice for optimal performance. It connects directly to your solar charger and then to the AC/DC panel of your RV so that you can use AC power.
You need ample power supplies by your batteries to make the move to solar to make sense for your camping style. Ideally, you’ll be in an area where you getting enough sunlight to keep your battery above the 50-percent threshold so that you have power every day.
If you’re buying the components of your solar kit separately, make sure that they are compatible with the voltage of your battery if you’re using something other than a 12-volt product. Remember that the essential thing about going solar is balancing what’s coming in with your solar panel with what is going out to run everything in your RV.
We like the option of matching each component separately for the best fit.
The cost savings are a compelling reason to use solar energy for your RV. That’s in addition to what you spare from going RVing in the first place. You can save up to 64 percent on a four-person camping trip, especially if you plan most meals at the site.
One of the best things about solar power is that you’ll see a significant reduction in your costs with each successive year of camping trips. The more you use it, the more you save—and recoup your investment on your solar panel and components for your RV.
But, wait! There’s more!
You also have the satisfaction of making eco-friendly choices that will reduce your carbon footprint. It’s a smart idea, given the fact that many take to the road in your RV to get closer to nature and farther away from stress. You’ll have more places to explore without being tied to a specific camping site for your RV each day.
There is one additional factor that you should consider when figuring out how much solar power do I need for my RV. That concerns the efficiency of what you’re running inside of your RV. Let’s go over some figures.
If you’re still using incandescent light bulbs, you’re missing out on some significant energy savings that can help play a direct role in how much solar power you must have each day. For example, a 60-watt bulb will use about 0.30 kWh per day. Swapping it out for an LED will use about one-quarter of the energy per day.
But that’s not the only way you can get the most out of solar power.
Upgrading your appliances to Energy Star products is an excellent way to save energy. Use them only when you need them and unplug them if you’re not going to use them for long stretches of time.
Another option is to work with the sun. Park your RV where it gets the most direct sunlight each day. When you’re not inside of it, draw the curtains to keep the RV from heating up inside so that you can cut down on how much you’ll use your air conditioners. Likewise, keep yourself cool with an awning or a cabana or beach tent to get out of the sun when you’re outside during the day.
We like these choices because it fits with the energy-saving concept.
RVing and solar power are the perfect match. Camping brings you closer to the outdoors and this renewable energy source gives you the freedom and peace of mind of making environmentally friendly decisions that you can pass on to your children. Fortunately, it’s easy to figure out what you need to get started. And reaping the benefits begins the first time you take to the road.
The key is to give yourself a little extra than your time estimates reveal. That way you can also be sure that you have a reliable source of power no matter where your journey takes you.
Ross Spark is devoted to propelling the use of solar-based and solar oriented systems around the world, something he has done on this site for over three years. Believing that expanding access to this perfect, rich, clean, and economical energy source will greatly impact our well being and our future generations well being.