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The Ultimate Buyer’s Guide: RV Solar Panels


Solar array

Solar power is just about the coolest thing since sliced bread. I mean, with solar power, you are making your electricity out of the sun. What else could you ask for in your path to being independent? In today’s guide, we will talk all about the different things you should consider when looking at RV solar panels for your RV. We will talk about when it makes sense, when it doesn’t, the benefits, the drawbacks, and just about whatever else you can think of.

1. Are RV Solar Panels Right for Me?

Solar power for RVs works great for people in certain situations. It does not make so much sense in others. For instance, solar power does not make sense for people that spend most of their time camping at regular campgrounds with electric hookups included in the price of the campsite.

While the solar panels are really cool, they are expensive. You will want to do some thorough research and calculations to make sure you are accurately anticipating the costs and benefits that come with solar.

Solar power can make a lot of sense for boondockers, or people that love camping out away from town, in places without any hookups. Boondocking requires you to be self-sufficient, and solar can extend how long you can stay out away from civilization.

That being said, you should ask yourself: How long do I last on my batteries anyway? If you don’t know, then go measure. Start with fully charged batteries and go camping for a day.

Just act how you normally would when camping, and then measure your battery percentage after 24 hours. This will give you a good idea of how much power you use in a normal day.

If you normally last 2 or 3 days on batteries, and you never really ever go camping for more than 2 or 3 days, then you are faced with the question: What do you need solar panels for anyway? If this is your situation, it might not make much sense to invest in solar panels.

Similarly, you should also consider how often you drive while camping. Some people are more the sightseer type. These people don’t plant themselves in one place for a week.

If you like to drive somewhere new every few days, then it probably doesn’t make sense for you to invest in solar either because your batteries will be charged much quicker by the running engine while you are driving.

Can I save money with RV Solar?

With all that being said, let’s look at the scenarios where an RVer could save money by installing solar. Say you are the type that generally stays at a campground with electrical hookups. But you want to escape and get out into some great boondocking sites.

As a boondocker, you might not even have to pay for a campsite at all. If installing solar allows you to save $45 a night for every night you go without paying for a campsite, then that can add up pretty quickly.

If the cost of your RV solar panel installation is $2,500, then it would take only 56 nights of free camping to recoup the cost of paying for those solar panels, which is not an insignificant number (of course, the cost of a solar system can rise above that figure, but we will discuss this further in section 3).

Especially for full-timers, the math starts to look really good. If you can sleep a majority of your nights away from paid campsites, then you will save up the money pretty fast. You will also have a much greater amount of independence.

Finally, there is a third group of people: people that don’t want to go completely solar but that want to install panels just to lengthen out how long their battery will last.

If your battery normally last you two days while camping, maybe installing a few panels can stretch it out to three, if your days are sunny.

Other motivations for installing solar panels are the desire to be self-reliant and the desire to cut greenhouse gas emissions. For people that have their house destroyed in a natural disaster, if their RV has solar, they won’t be left completely without power. Even just a few panels could prove useful in these cases.

When it comes to saving the environment, probably only full-timers or people that currently generate their electricity from a generator will see any meaningful drop in CO2 from going solar in their RV.

Altogether, there are many valid reasons to go solar, and there are many UN valid reasons to go solar. I encourage you to think through them all carefully, and also keep in mind that you might be someone who only wants to install a few. You can always add more later.

Appliance Energy Use

ItemApprox. Energy Usage
Fridge180 Watts
Microwave1,000 Watts
Light Bulb (Traditional)60 Watts
Light Bult (LED)8.5 Watts
Television200 Watts
Laptop60 Watts

Adding an RV solar panel also might not be for you if you run many large or power hungry appliances. There is a wide range in how much electricity people use.

Some people, like my Dad, can’t stand to sit around inside while camping. With him, it’s always on to the next adventure, and with him around we’re almost never in the RV during the day. For people like my parents, it’s much easier to generate enough power from solar for all their needs.

In contrast, some people love their RV. For them, the RV itself is the destination. If you are the type that loves watching TV all day, with the air conditioner on, and lights and everything else, then you will need to consider whether you will be willing to cut enough of that energy usage to make solar work for you

Air conditioning, in particular, is one appliance that can’t really be run with just solar power. It is a HUNGRY appliance and it’s not really likely that you would have enough roof space to install enough solar panels to be able to power that thing for more than just a few minutes a day.

Due to its huge power consumption, it is really just not practical to power an air conditioner with solar power. So just plan on air conditioning being a campsite-only luxury.

The above chart lists some common items that consume electricity in an RV. To determine how much electricity they are actually taking, you need to think in hours. For example, a laptop draws 60 watts.

If you are running a laptop for one hour, then you will have consumed 60 watt-hours or 0.06 kilowatt-hours. If the microwave, which draws 1,000 watts, is run for one hour, then it will have drawn a whole kilowatt-hour.

2. RV Solar Panel Equipment

RV solar panels
16557852 – wide angle view of solar panels used to power a rv.

So, what will it take to get your RV running on solar? The bare minimum that a solar system needs to work are the following:

  • Solar panels
  • Batteries
  • Controller
  • Battery Monitor

The solar panels make the electricity, the batteries store the electricity, and the controller makes sure it all happens without any problems. The controller is a must-have part of the solar system. Its job is to keep the flow of electricity within a safe range and to keep your batteries from frying.

The batteries are an important part of the system because the sun only shines for around half the day. In fact, depending on the time of year and on your weather, it only shines really powerfully for just a few hours a day.

When building your solar power system you will want to take into account that fact that many days are cloudy for part of the day, and that the sun’s rays are only really strong for a smaller part of the day.

You will generally need to generate all of the electricity you need for 24 hours in just 10 or so hours of the day, depending on your location.

How much solar and battery capacity you need will depend on how much electricity you use in a day. This number can vary widely. Some people are barely at home in their RV during the day. Other people love their RVs and are inside all day watching TV and microwaving popcorn while surfing the web.

Your first step will be to estimate your normal daily energy usage while you are camping. This will enable you to understand what your energy picture is. Using this number you will be able to calculate how much energy savings you will gain, and therefore how long it will take you to break even on the cost of going solar.

These numbers are all important in deciding if the cost of going solar will be worth it for you.

To estimate your actual daily energy usage, I recommend that you just go and camp for 24 hours on your battery. Do not plug in, do not turn on the motor, and do not do anything weird. Just act natural. Measure your battery percentage at the end of the 24 hours to get an idea of how much electricity you use in a day.

Measuring how much electricity your RV actually uses while in operation will help you be able to correctly plan to install enough solar generating capacity.

Power Requirement

Solar panels convert sunlight into electricity. Then, the electricity that is generated gets stored in your batteries. If you have enough solar and battery capacity, then the batteries should last you all night until the sun comes out again.

So let’s get technical. Electricity is usually measured in watt-hours. So if a particular light bulb is a 60-watt bulb, that means that it draws 60 watts from the electrical system while it is on. If it is on for one hour, that means that it will use 60 watt-hours of electricity from your system.

Solar panel energy output is measured similarly. A 100-watt solar panel will produce 100 watts when pointed at the sun. If it has been producing electricity at a steady stream of 100 watts for one hour, then it will have produced 100 watt-hours.

A kilowatt-hour is simply 1,000 watt-hours, and the kW/h is the unit that electric utilities use to measure your electricity use. For a home in the United States, electricity costs anywhere from 8-16 cents per kilowatt-hour.

To figure out approximately how much solar capacity you will need to install for your RV, you can do the battery-measuring camping experiment we just discussed. You can also try and estimate the energy usage of the various individual things you use in your RV, although that is prone to error.

How Much Solar Capacity Do I Need?

In having this whole discussion, remember that you can always install more panels later. If you feel unsure about the number of watts of capacity you need, then remember that you can just start with a few and always add more if they aren’t getting the job done for you.

It is also important to remember that 100 watts of stated capacity doesn’t always mean 100 watts. Let me explain. While a solar panel may be built to produce 100 watts, it will rarely ever produce at its full capacity.

This is because for most of the day the sun’s rays are not at their strongest. Also, there are clouds that can block the sunlight, or the panel could be tilted slightly away from the sun, or there might be inefficiencies in the system, or a million other little things.

The true output will be a bit less than the stated capacity. So you should plan for a 10-20% reduction.

All that said, it is possible to generate enough electricity to satisfy your basic needs with a system that isn’t too complicated or crazy expensive (unless of course, you want to power an air conditioner).

At the low end, you will need a system that can generate 9-10 kilowatt-hours per day. To be comfortable, you will want to have around 12 kilowatt-hours per day of generating capacity.

To reduce your need, you can also consider energy efficiency as part of the equation. Anything you can do to reduce the power consumption on board your RV can make your solar energy stretch a lot farther.

For example, a TV will draw power even when switched “off.” Newer “smart” TVs are worse when it comes to this. So that they can turn on quickly, they keep part of their components active even when the screen is off.

By plugging into a surge protector, and flipping the switch off when not in use, you can be sure the power supply to your appliances is cut when you want it to be.

Lightbulbs are another low hanging fruit when it comes to efficiency. A traditional light bulb draws 60 watts while turned on. Traditional light bulbs cost $2.00 and last for only 1,200 hours.

In contrast, new LED bulbs cost $5 and last for 25,000 hours. And here’s the kicker: LED bulbs that produce a 60-watt equivalent amount of light only draw 8.5 watts while in use.

These are two small things can stretch your battery life. I would encourage you to do some other research on energy saving practices that can go a long way in helping you make your solar dream a reality.

3. How much does RV solar cost?

How much does RV solar cost?

Solar panels could make financial sense for you if you like camping out in the wilderness, or “boondocking,” a lot. Since classic campsites usually have power hookups, then you probably don’t need solar if you like to stay at these sites most of the time.

The next big financial question is this: how much will a solar system cost? That number will depend on many things, but you can plan on these as some of your base expenses:

  • Solar Charge Controller: $100-$200
  • Wiring: ~$20
  • Batteries: If you need more storage capacity than your RV currently has, then a decent battery will cost you $200 each. (you should probably be fine using just your current batteries though, at least at first)

RV Solar Panels

Panels are the star of the show here, and they are also the most expensive part of the system. Their costs vary widely because of their different designs and efficiencies.

While you have many options, what you most likely want is a setup that includes polycrystalline rigid panels. This is the cheapest and most popular option. Rigid polycrystalline panels will cost you about $200 for enough capacity to generate one kilowatt-hour of electricity per day under ideal conditions.

Stated again, you will need ~$200 of solar panel for every kilowatt-hour you want to generate per day.

Let me walk you through the whole thing though, in case you are interested in other types of solar panels.

Cost for 100 watt panelFlexible PanelsRigid Panels
Monocrystalline Panels~$175~$105
Polycrystalline Panels~$140~$80

Monocrystalline vs. Polycrystalline Panels

The two main classes of solar panels are monocrystalline and polycrystalline. These names refer to the structure of the silicon inside of them.

Monocrystalline panels are more expensive because they are made of a purer silicon crystal. The process takes more time and energy to make them this way, but the power output is higher per square inch of panel space.

In other words, a 100-watt monocrystalline panel will tend to be smaller than a 100-watt polycrystalline panel.

Since your RV isn’t the International Space Station, and we aren’t extremely worried about getting maximum value out of every square inch of rooftop space, you will probably be fine with using polycrystalline solar panels that are a little less energy-dense per square inch but do cost less than the monocrystalline ones.

Solid panels vs. Flexible panels

This one is pretty self-explanatory. The flexible solar panels are more adaptive to curved surfaces, can be more aerodynamic, and more out of sight than traditional boxy, board panels. They are also a good bit pricier per watt though.

So unless you really need your solar panels out of sight, I would say that it is not worth having flexible panels. But this is of course totally up to you.

Cost of solar panels

The biggest question here is the cost of the solar panels. It is also the biggest variable because not everybody needs the same amount of electricity.

As a general rule, $200 of rigid, non-flexible solar panel will produce 1,000 watt-hours for you per day, under ideal conditions. This is equivalent to one kilowatt-hour.

If you are serious about living off of solar then you will need to produce at least 10 kilowatt-hours of electricity per day. That means that you will need 10 times that amount.

So as a general estimate, keeping in mind that there is a wide range of situations and panels, you will need at least $2,000 worth of panels.

Putting everything together, you shouldn’t expect the cost of going solar for your RV to cost less than $2,500. You can consider that a floor, because installation, cabling, and additional panels will all add to the cost.

If you are someone who is merely interested in extending their battery life while camping by using solar panels, then you have some more flexibility. How much solar capacity you install is totally up to you.

It just depends on how long you would like to extend your battery life for. You should just know that in general, you won’t reach a break-even point until you are generating at least 10 kilowatt-hours per day.

4. RV Solar Panel Installation

solar panels on roof of RV

Installation is the most complicated part for people that don’t have the tools or the knowledge to do the job.

If you are handy with basic tools and have a basic understanding of how the solar energy system works, then you should be capable of installing the solar panels and the rest of the equipment yourself.

If you do not feel comfortable doing it, then know that you can get a solar energy system professionally installed. This will just add to your overall cost of going solar.

Professional solar installers can make things a lot smoother by discussing your energy needs and recommending the best-priced components.

Keep in mind that they will most likely try and upsell you though, meaning, they will try and tell you that you need more solar capacity than you actually need.

RV Solar Panel Setup

The basic setup of your solar panels will look something like this: The panels will go on top of the RV. You will mount them securely however you want, but it usually involves using metal frames and screws.

Most people put their solar panels on hinges. This means that they can lie flat for traveling, but they can be raised to one side once you are camping.

This tilt is very important as the angle at which the panel faces the sun has a large impact on how much energy the panels will capture.

In general, you will want to park the RV at an east-west axis and be able to tilt your panels to face southward. This is more important the farther north you are.

Charge Controller

The charge controller is placed in between your panels and your batteries in the electrical pathway. The electricity generated by the solar panels is wired to the charge controller, and from the controller, the electricity is wired to the batteries.

You will want to make sure that the charge controller is rated to handle more electricity than your panels can produce. This is one thing that you don’t want to overload.

A charge controller is responsible for managing the flow of electricity from the panels into the electrical system of your RV. Kind of like how a dam can stop a flood, the controller will keep the charge under control and keep damage from happening to your system.

The most important job of the charge controller is that it will cut off the charge when the batteries are full. If you didn’t have any equipment to cut off the flow when full, the damage would be real and it would quickly decrease the life of your batteries.

There are two types of charge controllers: Pulse Width Modulation (PWM) and MPPT. MPPT controllers are more expensive and can harvest more energy coming in from the panels.

While this is a good thing, the additional cost is usually not worth it in small installations like the kind we are doing in an RV. Pulse Width Modulation controllers should get the job done just fine.

A good PWM charge controller will cost anywhere from $100 to $200. This is one component that will be worth the time to investigate fully and make sure you are buying a quality piece of equipment.

Keep in mind also that many people opt to buy a charge controller that has a higher capacity than they will need right now, just in case they decide to add more solar panels later.

Battery Monitor

This component is optional, but it does a very important job: the monitor will manage the level of charge in your batteries while they are discharging. Traditional lead-acid batteries (which are the most common type in use) will last a lot longer if you do not drain them below 50% capacity.

The battery monitor is the easiest way to make sure that they never drop below 50% charge. While this will allow them to last a lot longer, keep in mind that you will need to plan for the corresponding loss of 50% of your battery capacity when you do this.

To Go Solar Or To Not Go Solar, That Is The Question…

small solar panel
Sol

I hope this is a great starting point for your research on how to install a solar energy system in your RV. If you have mad it this far, then congratulations!

You probably are seriously looking into going solar, and I wish you the best in your journeys. Feel free to ask further questions or share your knowledge here in the comments. Give your opinions on the best solar equipment out there and we will all benefit!

Related Questions:

Should I buy one of those going solar “kits” for RVs? While this is completely up to you, I would suggest first doing your research and planning for exactly how much solar capacity you want to install, and how much capacity you want in your controller. From there you can go looking for equipment that fits the bill. If you happen to find a kit that has the equipment you are looking for, then go for it, otherwise, you will probably just be getting coerced in your decision making.

Are portable panels worth it? Again, you should do your own calculations, but know that portable panels rarely produce over 200W of output, and you only have a few hours a day to generate all of the electricity you need for the whole 24 hour period. Portable panels would probably be most useful for those wishing to extend the life of their battery while boondocking, but not necessarily for those who are trying to actually live off of solar in their RV.

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