Asking how much solar power you need to power your RV is akin to asking how long a piece of string is. This is because everybody’s needs are different.
For example, if you are the type of person that is barely using any electrical equipment in their RV, then you will probably have lower solar panel requirements than somebody that wants to keep their laptop charged while they have a TV blaring in the background.
So, how much solar power do I need for my RV? On average you would need a solar panel that is at least 800-watts. You need a 100ah per day per person, this mean 200ah batteries. However, this can be bumped up ever so slightly to account for slightly different conditions i.e. the placement of the solar panel.
That being said, we are going to try and answer the question the best that we possibly can do.
Table of Contents
Solar Panels Need Batteries
Fire and foremost, you have to remember that the power produced by the solar panels has to be stored somewhere. This means that you need to have a system of batteries. In fact, batteries are going to be your major limiting factor here. Let’s give you an example.
Let’s say you had an 800-watt solar panel. In ideal conditions, this can provide around 200 AH per day (more on what we mean by that in a short while).
So, if you have a 100 AH battery, or you are only using 50 AH of power per day, then there is no sense in having something anywhere near that size. It would be an absolute waste of money.
Therefore, before you read any further, think about the batteries that you already have stored inside of your RV. This will be your main limitation when it comes to choosing a solar panel. Obviously, you can switch out the batteries if you really wanted.
However, this can be quite expensive. Chances are that your batteries may already be providing you with all of the power that you need anyway (when charged with a generator), and you just want a method to charge them in a way that is somewhat more eco-friendly.
What is AH?
This now leads us onto the discussion of amperage-hour, or AH for short. It is important that you understand this. This way, you will be able to work out the exact size of solar panel you will likely need.
AH stands for the number of amps consumed by an appliance per hour. So, if you had something that has 20AH listed on it, this would mean that you could expect it to consume 20 amps per hour.
So, if you had a 200amp battery, it would last roughly 10-hours.
Don’t worry. It is pretty simple stuff. Most of the items around your RV are going to have their amps listed on it, so life is going to be made simple for you there. However, we will come to that.
Average RV Consumption
During the research for this article, we figured that we would look at the requirements that other people have when it comes to electricity usage. After all, we know everybody uses their RV differently.
Our experiences may not necessarily be the same as your experiences.
It seems that for the vast majority of people, 100ah per day per person staying in an RV is enough. This means 200ah batteries, and that requires a solar panel that is at least 800-watts.
However, this can be bumped up ever so slightly to account for slightly different conditions i.e. the placement of the solar panel.
Here in the chart below, you can see the average power consumption for electrical appliances:
|RV and Camping Appliances||Rates Watts (running)|
|RV Roof-Top AC (15,000 BTU)||2,000 W|
|RV Roof-Top AC (13,500 BTU)||1,500 W|
|RV Roof-Top AC (11,000 BTU)||1,010 W|
|Electric Water Heater (6 Gal.)||1,440 W|
|Clothes Washer||1,150 W|
|Electric Blanket||80 W|
|Space Heater||1,800 W|
|Coffee Maker||800 W|
|Electric Grill||1,650 W|
|Toaster||850 – 1,250 W|
|Dorm Size Refrigerator||350 W|
|12″ B&W TV||30 W|
|27″ Color TV||500 W|
|Satellite Dish & Receiver||30 W|
|Battery Charger (Cell Phone)||25 W|
|Inflator Pump||50 W|
Amperage Draw Chart (Appliances)
In the following table you can see how much amperage the most common devices consume during operation:
|Equipment||Amperage Draw||How long will the 200ah battery last? (Hours)|
|Coffee Maker||5-8 Amps||22|
|Television HD, Digital||1.5-4 Amps||40|
|Space Heater (1600 watts)||7-13 Amps||15|
|Water Heater (6-gallon, heating)||8-13 Amps||14|
|Satellite Receiver/Game Console||0.5-0.8 Amps||170|
|Vacuum (Hand-Held)||2-6 Amps||40|
|Hair Dryer (High)||7-13 Amps||15|
|Frying Pan (Cooking – High)||7-12 Amps||17|
|RV Converter (charging)||1-8 Amps||25|
|RV Air Conditioner (Running)||13-16 Amps||12|
|Furnace Fan||7-9 Amps||16|
|Microwave Oven (Standard)||7-13 Amps||15|
Working Out Your Energy Consumption
To determine the size of solar panel that you need, you are going to need to determine what your energy consumption is when you are using your RV. There are a couple of ways to do this.
The method most people seem to use is to go around and make a list of all of the appliances that are on constantly i.e. your fridge.
You will also want to make a note of the appliances that are turned on a lot of the time. For example, if you are using the TV for multiple hours per day, or charging a laptop.
This should give you a ballpark figure for the amount of energy that you will be consuming each day. It will not be 100% accurate, but it will be close.
If you want an accurate measurement, then your best option is to go camping and measure your power consumption yourself. You can use a battery monitor to check everything here. Remember, the batteries should never be dropping below 50%.
So, if you are constantly dropping below that, not only are you damaging your batteries, but you also need to factor that into the size of the solar panel that you have.
By now, you should have a rough idea of how many AH you are using each day. This leads us neatly onto the next section.
Choosing a Solar Panel Size
There are a few different methods that you can use to determine the solar panel size that you need. However, there is one method that we like to use above any other. This is good old simple math.
We are going to try and keep things simple here. By now, you should know your AH consumption. We are going to assume that it is 100ah.
We also need to know what the average amount of effective sunlight per day is. In most cases, this will be 6-hours. So, stick with that number. Unless you are traveling way up in the north of the country during the winter months, 6-hours is going to be a good estimate.
You can only expect the solar panel to charge for those 6-hours, although some may trickle in beyond this.
This means that the solar panel needs to be able to charge 100ah in 6-hours or 16.6ah per hour.
On average, 100-watts of solar panel will give you 5.43ah of power. This means to cover that 100ah, you would need at least 300-watts of solar panel, but you would probably pick up a 400-watt one, just to cover that extra bit of power.
Once you know the number of amps the solar panel needs to provide per hour, everything becomes much simpler. This is because every single solar panel on the market will tell you exactly how many amps it is able to produce per hour in effective sunlight.
Since you know your amperage requirements, and you know that you are getting about 6-hours per day, just do this calculation:
Amperage-hour requirements / 6 = the amperage that the solar panels need to output an hour.
Remember, you can use multiple solar panels to charge your batteries here. In some cases, this may be more beneficial. So, rather than purchasing a 300watt solar panel, you may want to purchase 3 x 100-watts.
Always purchase the best quality solar panels that you can afford. This way, you should be able to easily predict the amount of power that they are able to output. Some of the cheaper solar panels on the market can be somewhat sporadic.
How to Size your Solar Power System >> Check out the video below:
Choosing the Batteries
And now we cycle back around to the batteries i.e. how you are supposed to be storing the power. This is where things start to become a little bit more difficult.
This is because you can’t just use one battery, at least in most cases. You need a few of them to be charged by the solar panel in order to provide your RV with all of the power that it needs. If you were running just one battery, then the power would drain pretty quickly.
Up until about 50ah consumed per day, you can probably use just a couple of 12V batteries. If you are using under 20ah per day, then you can use a single battery.
Above 50ah, then you may want to creep into the 3-4 batteries per day range. Over 300ah, and you are starting to get into the 8 battery range which, of course, is going to be incredibly expensive.
For most people, around 4 batteries are going to be enough. This can help provide all of the power that a small family needs.
If you are consuming more power than those batteries are able to provide, then it would probably be best to try and cut back on your energy consumption as opposed to buying a new battery, as a quality battery can easily set you back over $1,000.
How Do You Run Appliances with a Higher Wattage?
Chances are that, by now, you will have a rough idea about the size of solar panel that you want. You will have a wattage in mind.
However, by walking around your RV, you will probably also have worked out that a lot of those appliances require a higher wattage than your solar panel is able to provide.
So, how do you get around that? Well, you need to buy an inverter.
The job of an inverter is to convert the power from the batteries into a usable form for the appliances that require a higher wattage.
This normally means converting the power to 110-volts. So, that 12V battery, or whatever size battery you have, gets converted into a power that can actually be used.
We won’t talk too much about that here, mostly because wattage is quite a complicated subject and we want to save that for its own article.
So, what size inverter do you need? Well, an inverter that is large enough to cover the wattage of the appliances, plus a little bit more.
Most people suggest that you get an inverter at least 15% higher than your wattage needs. This will help to ensure that you are completely covered and your appliances get all of the power that they need.
Once again, always make sure that you purchase the best quality equipment that you can afford. You need to ensure that the inverter is able to provide stable power to your appliances.
If it can’t, then you are going to be running the risk of damaging the appliances everything is hooked up to. Obviously, this is going to be the last thing that you want to be dealing with while you are out there on the road.
Hopefully, this helped you to understand a little bit better how much solar power you need to run your RV on. It is likely that your RV power consumption is going to be a lot less than you think, particularly if you are driving on the road all day.
Once you have a solar panel installed (or a couple of them, if your power consumption is that high), then they should be more than enough to keep your batteries topped up and providing a bit of excitement out there on the open road.
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