13 Questions About RV Solar Panels For Beginners
What Makes Up An RV Solar Power System?
An RV Solar system is just like any other off-grid solar system which does not feed power back into the local power grid. In a nutshell, there are 3 primary components.
- Solar panels to capture light and convert it to electricity.
- A charge controller to take the energy from the solar panels and convert it to the DC voltage and current necessary to charge your batteries and/or power your RV when the sun is shining.
- Batteries to store the solar energy and power your RV.
- Other optional components to regulate power, switch from solar to shore power and provide AC power to the RV from a DC battery source.
Do I Need A Generator If I Have Solar Panels On My RV?
A generator is not needed for most RVs. Critical systems in most RVs like lights, heat, hot water, the water pump, power awnings, jacks, fans, the refrigerator, etc. will all run on a combination of DC power from your batteries and propane.
Generators are only needed when you don’t have access to shore power and your house batteries are dead, you need to run your AC power outlets, the air conditioners or to charge your batteries if you don’t have a solar system.
Can You Use Household Solar Panels For RV?
There is no difference between an “RV” and a household solar panel. Both types of panels use the same materials and construction methods so they are indistinguishable from one another. The only difference between residential and RV applications is size.
Residential panels can be mounted on rigid surfaces or mounts which can support larger panels than what you may typically use on an RV. The most common size RV is a panel is a 100-watt unit, although larger ones can be used if space allows.
100 watt panels are relatively small and lightweight which makes them perfect for mounting on a smaller, less sturdy RV roof. There are many houses and cabins which also use arrays of 100-watt panels as well, so these are not “RV specific” panels.
What Types Of Solar Panels Are Available For RV’s?
When shopping for solar panels for your RV you will come across several options that you’ll need to choose from. These options will include size, material, voltage, and style. Let’s cover some specifics on those options.
- Size. Solar panels are sized by wattage. The wattage will be directly correlated to the physical size and weight of the panel. The higher the watts, the larger the panel. This is because all solar panels are made up of a series of individual solar cells, each of which has a specific voltage and current output. More cells = more watts = larger panel. Voltage and output current are set by how the cells are arranged and connected to each other to make the complete panel. The most common solar panels for RV applications are 100 W, 12V panels. Panels of other sizes and voltages (24 V is next most common) may be better options for your specific RV.
- Material. The two primary material types used in solar panels are monocrystal and polycrystal. These terms relate to the type of silicone crystals used to make the panel. Monocrystalline panels are more efficient than polycrystalline panels so they tend to be smaller and lighter for the same voltage and wattage. Monocrystalline panels are also more expensive and have a more uniform black appearance to the cells then their bluish polycrystalline brothers.
- Voltage. The most common voltage for solar panels on an RV is 12V. These panels work well most types of charge controllers because the voltage does not have to be heavily down regulated to work with a standard RV 12V battery/DC electrical system. To use higher voltage panels you’ll need a charge controller which can regulate that voltage down to the same voltage as your RV’s battery bank.
- Style. The two panel styles most commonly used in RV applications are standard rigid panels, and flexible panels. There are advantages and disadvantages to each so you’ll need to study them carefully before choosing.
Are Flexible Solar Panels Any Good For An RV?
Flexible solar panels can be a great addition to any RV. They are easy to work with and they bond directly to the roof surface of the RV without any need to drill holes in the roof for mounting. This means fewer chances to introduce leaks in your RV roof. There are a few downsides you’ll need to consider.
- First, they are less durable than their rigid siblings. They are more susceptible to hail, tree branch or other physical damage.
- They are also harder to keep clean. Dirty panels make less power
- They can’t be tilted. Depending on your location and time of the year, tilting your panels toward the sun can provide a significant increase in power output. Flexible panels cannot be tilted like a rigid panel on a tiltable mount.
- They are more expensive. Flexible panels are more expensive per watt then rigid panels.
- They are not available in as many sizes. There are only a few sizes of flexible panels available. If those won’t fit the space you have available or your power needs then you’re out of luck.
Can Flexible Solar Panels Overheat?
Flexible solar panels, like all solar panels, can overheat. When overheating occurs, the efficiency of the panel can drop dramatically. In extreme (and unlikely circumstanced) the panel can even be permanently damaged by excess heat. Manufacturers specifically test their panels under extreme conditions and build them to withstand those circumstances.
For flexible panels, the best way to keep them from overheating is to keep them clean and well maintained. Also, consult with the manufacturer for any specific tips they may have for installation and maintenance which will help you get the most from your panels.
Are Solar Panels On RV Worth It? – Refer To Existing Article
The question of whether solar panels on an RV are worth can only be answered by how much you spend to install the system vs. how much you use it vs. what you value in your system. If you spend $20,000 for a top-of-the-line system and then only use your RV in private campgrounds attached to shore power then your system probably wasn’t worth it. On the other hand, if you frequently boondock for extended periods of time then your solar system can not only be worth it, but indispensable.
The question of whether or not something is “worth it” is complex and depends on how you value what you are judging. If you want to look at it purely quantitatively, a 3500-watt generator can be bought for about the same cost as a basic off-grid solar system large enough to run an RV for an extended period of time. If you boondock enough that your fuel costs for the generator exceed the cost of battery wear and system maintenance on your solar system then it is quantitatively worth it. If not, then it’s not.
If you value more than just raw dollars and cents then the scales can easily tip either way. In the above example, your solar system won’t run your air conditioner or most of your AC outlets while the generator will. If that’s important to you then the generator may be the better option. If you value the idea of not using fossil fuels, or frequently camp places where obtaining fuel for a generator is difficult then the solar system is worth it.
Can I Run An Air Conditioner With Solar Power?
Yes, you can run air conditioners with an appropriately sized solar power system. The system will have to include a large battery bank, large solar panel array, large power inverters, and stout wiring between the components. In other words, it will be very expensive, heavy, and complex. For those reasons, running air conditioners from an RV solar system is generally considered impractical.
While it can be done, it would be significantly less expensive and much easier to just carry a generator capable of running your ACs along with you. UsUsinghe the generator when running the ACs is a must and go straight solar when it is not.
How Much Does It Cost To Install Solar Panels On My RV?
Installing solar on your RV can be done for as little as $100 or less, or as much as $20,000 or more. It all depends on the size and complexity of your system, the components you choose, and how much of the install you can handle yourself.
Don’t forget that solar panels are just a piece of a larger solar system. Installing panels alone won’t help you unless your goal is to create a reflective rescue beacon visible from the space station. When considering the cost of solar panels, make sure you have a completed system plan outlined including the panels, mounts, batteries, wiring, charge controller, inverters, switching gear, etc. that will do everything you need it to. Those components can add up quickly.
Who Makes Good Solar Panels For RVs?
There are many quality manufacturers of solar panels for RVs. Some of the most common sources are Renogy, Go Power!, WindyNation, HQST, and mighty max. Be careful ordering from some of the major internet retailers, many of the products peddled there are of questionable quality from foreign sources. While initial panel quality can be an issue, service and support down the road will likely be non-existent.
This can make them a poor choice for something as critical as the power that runs your furnace or water pump. This is also the case for the other components of your solar system. Remember, the panels just convert the sun’s rays to electricity. There are a lot of other components in your system that make that power usable. Choosing quality products from reliable sources can keep you out of trouble down the road.
Can I Mix Old And New Batteries For My Solar Power System In My RV?
Mixing batteries of any type in a solar system is a complex question and is generally discouraged for a number of reasons. In most RV solar systems, the batteries are charged by a single charging source at a time. When the solar system is active, that source is the solar charge controller.
That single charge views your collection of batteries as one “battery”. Any differences in the individual batteries that make up the larger battery array will result in imbalances of power flow within the array. In the case of old vs new batteries, the older batteries will drain faster than the newer ones.
When they drain, their voltage drops faster than the newer batteries. To correct for that drop, they will draw power from the newer batteries to balance themselves out. This makes the overall array less efficient.
When charging, the opposite happens. The old batteries won’t charge as efficiently so they’ll draw more power and generate more heat than the new batteries and the battery bank won’t charge as quickly as it would if all the batteries were new. For these reasons, it’s highly recommended that all your batteries be as close to the same age as possible.
The specific brand of the solar panel is not very important when choosing panels for your RV. It is important that you choose panels from a reputable brand with a history of providing solid support. In the rare event that you have a panel failure, having that support will make getting your issues solved much easier.
Does The Brand Of Solar Panels Matter For My RV
Also, when putting together a solar system it is best to buy all your panels from the same manufacturer. Like batteries, differences in the panels can cause inefficiencies in the system. Buying all the panels from the same manufacturer can ensure that your panels are well-matched to each other.
If you need to buy from different manufacturers, look at the panel’s specs and try to match them as well as possible to the existing panels in your system, paying particular attention to the voltage and current outputs generated by the panel.