12v Solar Panel Systems

Solar energy is a great way to go if you are looking for a greener way to supply electricity to your appliances. While it is most commonly seen as an energy source for the home, the 12V solar panel is most commonly found installed in motorhomes and caravans. This means that even when you are on the move in your motorhome, solar power can still fuel things like your fridge, TV, and even water pump. So you can go green wherever you are.

12V Solar Panels and Motorhomes

The 12V solar panel is seen as the best option for motorhomes, caravans, and even boats. They provide just the right amount of power to help keep all of your basic appliances and electrical items running – from phone chargers to fridges and lightbulbs. If you are planning on going on holiday in one of these vehicles, then choosing a solar panel to help keep everything running is a much greener option.

Plus, it’s often a cheaper option in the long run. Even if you are holidaying in a cloudy location, your solar panels will still be able to gather charge. Of course, the question of which 12V solar panel you should choose is often a lot harder. The size all depends on what you will be using, which is what we will look at next.


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Calculating What You Need

When it comes to choosing a solar panel for your motorhome, you need to know how much energy each of your appliances uses over the period of a day. There are several ways that you can do this. The majority of appliances should have a sticker on them somewhere that states the amount of energy they use, making the consumption levels easier for you to calculate. However, it is also possible to calculate a rough estimate for the power consumption of individual appliances. You can then add them together to calculate your daily requirements. Here is a quick example, all based on 12V solar panels:


  • 4x10w = energy saving LED lights used for three hours per day
  • 1x40w = LCD TV used for two hours per day
  • 1x20w = water pump used for no more than 30mins per day


Next, we take these calculations and put them together as shown below:

  • 4x10x3 40×2 20/2 = 210w/h (watts per hour)

You can do this very easily with your own appliances, and when it is done, you will be able to calculate wat size 12V solar panel you will need for your motorhome or caravan.

Calculating the Size of Your 12V Solar Panel

The first, and perhaps most important, thing to remember is that the average amount of power that is generated by your motorhome solar panel should be (at least) equal to or greater than the average amount of power consumed by your appliances each day.

It’s easy to explain this further with a simple equation. If you assume that you will have around five hours of sunlight on a typical day, and that the size of the solar panel on your motorhome roof is 50w, we end up with this equation:

  • 50 x 5 = 250w/h

This result is just about in line with the average daily power consumption of 210w/h. It is also essential to remember, however, that some energy losses will occur. This will occur primarily in the solar charge and controller cables, but also due to battery discharge – a very natural occurrence. Generally, these will remain within 20% of the total output, and so it is a good choice to select a solar panel that offers a daily rate that is approximately 20% higher than your daily power requirements. This way, you know you will be able to keep everything sufficiently powered.

It’s not always easy to estimate what your daily power consumption will be, especially when the power rating for individual appliances is not readily available. If this is the case for you, then all is not lost. You can still take the appliances in question into account. Just follow the below steps:


  • If you need to trickle charge your battery in order to compensate for the self-discharge, a small solar panel or charging kit of 5-10w should be more than enough.
  • If you need some extra power for small items, like phone charging and low computer usage, it is recommended that you get a 40-50w solar panel or charging kit.
  • If you are looking for something that can take larger loads, like a TV, frequent water pump use, or the use of light bulbs, it is suggested that a larger 80-100w solar panel or charging kit is used.


Want to Know More?

Have you found yourself interested in solar panels? If you want to know more then make sure you head to our marketplace where you can find our full range of products, each with the relevant information. Or simply give us a ring using the number at the top of this page and have a chat.

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