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RV solar is an excellent option to power your appliances while camping off the grid.
It can easily offset the use of a noisy and gas-guzzling RV generator.
But, can you power an RV air conditioner with solar?
Sure, you can power an RV air conditioner with solar for as long as you like, given you have the right size solar power setup. To power your RV AC, you need sufficient solar panels, a big enough battery bank, and a power inverter.
In this post, we’ll take a look at how much solar power you need to run your RV air conditioner. We’ll dive deep and talk about the size of the solar array, battery bank, and inverter you need to make sure everything runs smoothly.
I’ll also be talking about the things you can do to make running your RV AC easy on your solar system.
Lastly, we’ll take a brief look at RV solar panel installation and the alternative methods to cool your RV this summer.
But first, let’s look at some basics of solar power, starting with the pros and cons of RV solar.
Table of Contents
Pros and Cons of RV Solar Power
Before finding out how much solar power you need to run your RV air conditioner, we need to answer one question.
Is solar worth it to power your RV AC?
The only way to answer this question accurately is to weigh the pros and cons of using solar power for your RV.
Benefits of Powering RV AC with Solar
Solar energy is FREE forever: Your solar panels don’t need fuel to run. It uses sunlight to produce electricity. Therefore, after the initial investment, your solar panels will produce electricity for the lifetime of the setup.
Solar makes ZERO noise: Unlike your generator, your solar system doesn’t make any sound while running. You’ll be able to enjoy the serenity of nature while your solar panels do their things in the background.
Produces NO harmful gases: Because solar panels don’t use combustible fuel to run, it does not produce any harmful gases. This means you don’t have to worry about dying in your sleep.
Needs little to NO maintenance: Solar panels have no moving parts in them, which eliminates the chance of anything breaking inside. A little bit of cleaning from time to time and they will easily keep you powered for over a few decades.
Drawbacks of Powering RV AC with Solar
Solar is a COSTLY investment: Solar panels are not the most expensive component in your solar setup. It becomes a costly investment when all the components add up, especially the deep cycle batteries. Your house batteries will take up the biggest chunk of your budget.
NOT an on-demand source of power: unlike your RV generator, solar cannot produce power anytime you want. Your solar panels will only produce electricity when the sun is shining, and nothing is obstructing the sun’s rays.
How do Solar Panels Power an RV Air Conditioner?
To know how solar panels power an RV air condition, you need to understand how an RV solar power system works.
As the sun’s rays hit the solar panels, the photovoltaic cells in the panels take the sunlight and turn it into electrical energy.
The power produced by the solar panels is DC or Direct Current.
This Direct Current is then sent to a charge controller, which regulates and maintains the flow of current necessary to charge the batteries.
You can use the battery to directly power all your 12v DC appliances like your coach lights, vent fans, USB outlets, etc.
However, appliances like microwaves, air conditioners use AC or Alternating Current to function. To power such appliances, you need to convert the 12-volt DC power to 120-volt AC.
This is done by a power inverter which takes the DC power and converts it to AC. With the right size inverter, you should be able to run any high draw appliance like an RV rooftop AC.
This is a bird’s eye view of how an RV solar system works.
Before moving on to answering how much solar we need to run an RV air conditioner, we need to know how much power RV air conditioners use.
How many Watts does an RV Air Conditioner Use?
Before determining how many watts of solar panels you need to run your RV air conditioner, you need to know how much power they consume.
Generally, air conditioners have two different wattage ratings.
i.e. Starting and Running Wattage.
The starting watts are the amount of power the AC unit draws every time the compressor cycles on. Whereas, running watts are the continuous power it uses to function properly.
Note: It takes 2-3 seconds of starting watts to cycle the compressor.
Generally, starting watts of an RV AC are significantly higher compared to its running watts. The starting and running watts of an RV air conditioner may vary depending on the type, size, and brand of the unit.
Therefore, you need to check the wattage ratings of your specific unit before you proceed further. You’ll find the wattage ratings of your AC unit on a sticker on the unit or in the user manual.
You can look up the model online if you don’t have the user manual. You can also use the meter on your electric panel or use an RV surge protector that has a display showing how much electricity went through.
To give you an idea, here are the most common RV air conditioner sizes and their wattage ratings. The wattage ratings on this table are an industry standard and may vary from your unit.
| BTU Rating | Starting Wattage | Running Wattage |
|---|---|---|
| 11000 | 1600 | 1010 |
| 13500 | 2800 | 1800 |
| 15000 | 3300 | 2000 |
Once you have your AC unit’s wattage ratings in hand, we can proceed towards calculating the total solar needed to run your RV air conditioner.
How much Solar Power do you Need to Run an RV Air Conditioner?
You found out how many watts your RV air conditioner needs to start and run properly.
Now it’s just a matter of selecting the right size solar array, batteries, and an inverter to keep up with the demand.
The idea is to create a balance between the energy created and the energy used. This will help prevent under-sizing or over-sizing your solar system.
To keep things simple, let us use a hypothetical scenario.
Let’s say, we have a single 13500 BTU rooftop air conditioner that will run about 4 hours a day. We’ll also assume we get a total of 6 hours of sunshine and calculate the size of our RV solar power system to just power the AC unit alone.
Let’s start by finding out the number of solar panels we need.
How many Solar Panels do I need to Run my RV AC?
From the table above, a 13500 BTU RV air conditioner needs 2800 starting and 1800 running watts of power.
That means, every time the compressor cycles on, it draws 2800 watts. Then, the wattage consumption comes down to 1800 watts.
Because we’ll run our AC for 4 hours straight, the total power consumption will be 4 hours * 1800 watts = 7200 watt-hours.
So, you need 7200 watt-hours of power to run the air conditioner for 4 hours.
Because we are getting 6 hours of solid sunshine, we need to produce a total of 1200 watts of solar energy per hour (7200/6 hours).
So to run your 13500 BTU AC unit, your solar panels need to produce a bare minimum of 1200 watts of power, every hour, for six hours straight.
In terms of the number of solar panels, you’ll need:
Depending on the available space on your RV roof, you need to choose the efficiency of the solar panels. If you have less space, you need higher wattage panels and vice versa.
Now you know the number of solar panels you need to run your air conditioner. However, solar panels cant power appliances directly. You need a battery bank to power your air conditioner.
How many Batteries do I Need to Run my RV Air Conditioner?
Before sizing your solar battery bank, you need to understand something.
i.e. The primary function of your solar panels is to produce power to recharge your house batteries. Your house batteries are what power your appliances.
This means you need deep cycle batteries to store the 1200 watts of energy coming in every hour from your solar panels to run your AC unit.
But the question is, how much battery power do you need?
Before answering this question, we need to know a bit about deep cycle batteries. The deep cycle batteries commonly used in RVs come with a capacity of 100 ah (Amp-Hour) at 12 volts.
We know, our 13500 BTU air conditioner uses 7400 watt-hours of power to run continuously for 4 hours.
If we plug this into Watts Law, we get:
7400 watt-hours = amps * 12 volts
Amp-hours = 7400 / 12
Amp-hours = 600
You need a total of 600 ah battery capacity to run your air conditioner for 4 hours.
Note: A fully charged 600 ah battery bank can run your AC for 4 hours without solar panels.
However, you need to understand a few things before determining how many batteries that equates to.
There are various types of deep cycle batteries and the most commonly used in RVs are lead-acid and lithium-ion batteries.
With lead-acid batteries, you can’t discharge them past 50% of their capacity. That means, with a 100 ah battery, you just have 50 ah of usable charge.
On the other hand, lithium batteries can be discharged completely. However, I would recommend not going beyond 80%.
So, you need to calculate the number of batteries depending on the type of battery you choose.
For example, if you go with lead-acid batteries, you’ll need 12 batteries to get a usable 600 ah of charge. Whereas, you can use 6 lithium batteries to get the same.
Do you have the Right Size Power Inverter?
With the right size solar array and battery bank, you just have to get a power inverter.
The power generated by the panels and stored in the batteries is 12v Direct Current (DC).
But, your air conditioner runs on 120v Alternating Current (AC).
That means you need a way to convert the 12v DC to 120V AC to run your RV AC unit.
That’s where a power inverter comes and converts the DC to AC so you can run all your 120-volt household appliances.
However, when sizing your RV power inverter to run your AC, you’ll want a size that is at least equal to the starting watts of the AC unit. In our case, to start a 13500 BTU air conditioner, you need a 2800 watt inverter.
But, sizing an inverter that is exactly equal to the starting watts will overload the inverter, which is bad for the inverter. You need to add a bit of buffer wattage of about 20-25% of the starting watts.
In our case, to run our 13500 BTU unit without any issue, we need an inverter that is at least 3500 watts in size.
Putting the Whole System Together
With the analogy of running a 13500 BTU RV air conditioner, you should have a good idea of how much solar power you need to run your AC unit.
To recap, you need enough solar panels to produce 1200 watts of power every hour for 6 hours. A battery bank of at least 600 ah and an inverter of 3500 watts.
However, there are a few additional things you need to know before you consider these numbers.
At first, we assumed that your house batteries are at 100% charge and you were running the air conditioner when your panels were producing power.
But, what if your batteries were not at 100% and you also used the AC for some time after sunset?
Let’s say your battery bank was at 50% and because your solar panels are producing the exact amount of power used by the AC, your batteries are not receiving any juice.
That means you’re just left with 50% battery capacity for the night, which will further deplete your batteries. Plus, you may not get the same sunshine every day.
Therefore, it is good practice to wait till the batteries reach 100% charge level before running the air conditioner.
This will result in a dead battery bank very soon.
So to avoid this from happening, you need to size your solar array big enough so that it powers the AC and charges the battery at the same time.
Alternatively, you need to run your RV generator or turn off the air conditioner to charge the house batteries.
How to Make Running AC Easy on the Solar Power System?
Now you know how much solar power you need to run your RV air conditioner.
It’s now time to look at a few ways to make running the AC easy on the system, less taxing, and reduce the overall power consumption.
Consider Installing a Soft Start
A soft starter, also known as an easy starter, is a device that reduces the initial surge of electricity needed every time the compressor kicks on.
It can significantly reduce the starting wattage of your air conditioner unit allowing you to run the AC unit with a small size solar inverter.
Installing an easy start is pretty straightforward, and most of us with little electrical knowledge can do it ourselves.
Here is a great video you can follow to get it installed in under 10 minutes.
Buy an Efficient AC Unit
Many factors contribute to the efficiency of your RV air conditioner.
Of them, the most important is the age and how worn out the AC unit is.
Most RV rooftop units that are in the market today are built with efficiency in mind. They use advanced technology that reduces the total power consumption and the initial power surge.
Alternatively, you can also size down your air conditioner to reduce the overall power consumption.
Here is a good 8000 BTU portable unit and a 9000 BTU mini-split unit to consider for your RV.
Insulate your RV
On a hot day, when the sun is baking your rig, you’ll find your RV air conditioner is consuming a lot of power.
This happens because the outside heat can easily penetrate the wall of your RV due to lack or poor insulation. This forces your compressor to run frequently for longer intervals to reach the set temperature.
To make it easy on your AC unit and solar power system, insulate your RV properly, especially the glass windows.
Proper insulating will reduce the heat from getting in and cold air from getting out.
How to Install Solar Panels on your RV?
Now you know how many solar panels you need to power your air conditioner and made your purchase.
It’s time to install the panels on your RV roof.
There are two ways to install solar panels on your RV roof.
Hire a professional or do it yourself.
Hooking up solar panels on your RV is pretty easy, that even the most non-technical people can install it alone.
Here is a step-by-step guide to mounting the panels on your RV.
Step#1: Inspect the roof of your RV to find any visible damages.
Step#2: Next, map out the usable space on the roof to lay down the panels.
Step#3: Mark and drill holes for the mounting brackets. Using a caulking gun, seal the holes and make them watertight.
Step#4: Screw the panels and connect the panels to your charge controller.
Note: Flexible solar panels can be mounted on the roof using special adhesives. You don’t need to drill holes to install them.
Is it Worth the Investment?
Be it big or small, you can power your RV air conditioner with solar.
All you have to do is make sure that you size your RV solar power system big enough.
However, whether or not investing in such a big solar system makes sense will depend on the type of boondocker you are.
You boondock occasionally: If you go boondocking a few times a year, then investing in such a big system will not be worth it. A portable generator will be an ideal option to power your RV AC. For other things, you can invest in a portable solar system or solar generator.
You’re a proper boondocker: If you’re regularly camping off the grid and/or are a full-time boondocker, investing in such a solar power setup is ideal. Dry camping for extended periods requires a lot of power and using a generator means carrying and burning through gallons of fuel. You should consider investing in a complete solar setup.
Therefore, evaluate your needs accurately before diving into the solar route.
Alternatives to Cooling your RV
Keeping your RV cool when the sun is baking hot is important to keep your family and pets happy while boondocking.
However, there are ways to keep your rig cool if you don’t have a large solar setup to power an RV air conditioner.
Here are a few ways to consider:
- Invest in a swamp cooler that draws unbelievably less power compared to AC units, but cools well
- Keep all the windows open to increase air circulation. Additionally, use your vent fans to circulate air on a calm day
- Create shade by extending your RV awnings
- Start cooking outdoors as using an oven or stove to cook inside your RV can significantly raise the temperature
- Switch to LED lights as they radiate less heat compared to other types of light
- Consider parking under a tree to prevent the sun from baking your rig. Use portable solar panels to recharge your batteries when doing so
Conclusion
Yes, powering your RV air conditioner with solar is possible. But you need to have a big enough solar setup to generate and store this power.
Make sure you have calculated how much power your air conditioner uses before sizing solar panels, battery bank, and the inverter.
In the end, there are other ways to cool your RV if investing in such a large solar system is not worth it for you.
