System Guide – How Do Campervan Solar Panels Work?

This quick but comprehensive guide contains the answers to all the relevant questions we could find on Campervan Solar Panels.

If you are wondering what type of Campervan solar panels to fit and how much power you are going to need, you have come to the right place, so read on.

Are Campervan Solar Panels Essential?

Campervan solar panels are not essential. Before the invention of solar panels, the owners of Campervans got on just fine without them, and you could too.

However, the fact that Campervan solar panels are not a necessity shouldn’t put you off having them.

If you use a Campervan without solar panels fitted you will regularly have to ensure that your leisure batteries are constantly topped up. The only way for you to do that, is by running the engine.

With the current cost of fuel, as well as the focus on the environment, I’m sure you’ll agree that it’s not an ideal situation.

What if someone was to come up with a way to keep those batteries topped up for free, allowing you to stay off grid for longer, without having to pollute the environment? Now wouldn’t that be desirable?

Why Have Campervan Solar Panels Fitted At All?

There are numerous benefits of having a Campervan solar system on your vehicle, they include, but are not limited to:

  • Campervan solar panels will keep all your batteries constantly topped up with power for free
  • Campervan solar panels require very little maintenance
  • Charging the batteries with Solar Energy does not pollute the air with Hydrocarbons
  • Campervan solar panels will allow you to live off the grid for longer, actually much longer
  • Using solar power is becoming more affordable, saving you lots of money, especially with the current ridiculous price of fuel
  • Most of the solar system is outside of the vehicle, up on the roof, so it saves precious space
  • Campervan solar panels are now far more rugged and durable than they used to be. They won’t crack and fail with minor bumps and scratches like they used to
  • Modern solar panels work in cloudy weather too, ideal for the UK
  • The price of solar components is falling, at the same time their efficiency is climbing

I’m sure there are many other advantages of having Campervan solar panels, but I’m sure the list above is already enough to pique your interest.

Campervan Solar Panels – The Solar Charging System Explained

How Do Campervan Solar Panels Work - Solar Wiring Diagram

If you don’t currently have Campervan solar panels, when you park up to camp, you will begin using, and draining your leisure batteries in order to power your appliances.

All of the time that you are using anything that requires power while you are camping, your leisure batteries are being drained and not replenished.

At some point your leisure batteries will reach a critical level and you will run out of power. You will then have to start the vehicle and use it’s alternator to recharge the leisure batteries.

Running an engine when the vehicle is static is not only expensive, in terms of paying for the fuel, but it is also extremely bad for the environment.

However, in simple terms, here’s how Campervan solar panels do the job of topping up the leisure batteries, without having to start the vehicle for you.

Assuming it is daytime, the sun’s rays shine onto the solar panels on the roof of your vehicle. The solar panels work their magic and convert that solar energy from the rays of sunlight into electricity.

The newly created electricity flows down through cables to a solar charge controller, where is is released by more cable at pre-set voltage and ampage ranges that are suitable for your batteries to receive.

Your leisure batteries receive the energy and use it to top themselves up, providing power to run all of your electrical appliance needs. This cycle continues, automatically for as long as the sun is shining, and whether you are driving the vehicle or it is parked up.

What happens at night, I hear you ask? Well, leisure batteries, and the size and capacity of your system are designed to operate in such a way that they should be able to provide you with more than enough power to last through the night. The free solar charging will commence again as soon as the sun comes up.

How Do Campervan Solar Panels Capture The Sun’s Light And Turn It Into Electricity?

I could give you the benefit of my advice as to what I think is going on inside a solar panel, or more accurately a single solar cell, but I think the Office of Energy Efficiency and Renewable Energy explains it better, so here it is:

When light shines on a photovoltaic (PV) cell – also called a solar cell – that light may be reflected, absorbed, or pass right through the cell. The PV cell is composed of semiconductor material; the “semi” means that it can conduct electricity better than an insulator but not as well as a good conductor like a metal. There are several different semiconductor materials used in PV cells.

When the semiconductor is exposed to light, it absorbs the light’s energy and transfers it to negatively charged particles in the material called electrons. This extra energy allows the electrons to flow through the material as an electrical current. This current is extracted through conductive metal contacts – the grid-like lines on a solar cells – and can then be used to power your home and the rest of the electric grid.

Are There Different Types Of Campervan Solar Panels?

There are numerous different types of solar panels, and new ones are being invented every year. However, when it comes to viable Campervan solar panels, there are only 2 types being used, and the most popular one of them is used 95% of the time.

The 2 types of Campervan solar panels in use are:

Monocrystalline Solar Panels

How Do Campervan Solar Panels Work - Monocrystalline Solar Panels

Monocrystalline solar cells are the most popular option on the market, as well as the most efficient form of solar cell. While they also tend to be the more expensive option, with Monocrystalline cells you are guaranteed decent levels of efficiency in all weather conditions, making them a great option for Campervan solar systems.

Polycrystalline Solar Panels

Polycrystalline solar panels are solar panels that consist of several crystals of silicon in a single PV cell. Several fragments of silicon are melted together to form the wafers of polycrystalline solar panels. In the case of polycrystalline solar cells, the vat of molten silicon used to produce the cells is allowed to cool on the panel itself.

These solar panels have a surface that looks like a mosaic. They have a square shape and a shining blue hue as they are made up of several polycrystalline silicon. As there are multiple silicon crystals in each cell, polycrystalline panels allow little movement of electrons inside the cells making them far less efficient than Monocrystalline solar cells.

Almost all Campervan solar panels are Monocrystalline solar panels.

Are Campervan Solar Panels Expensive?

Surprisingly to me, No, Campervan solar panels are not expensive at all. A single 150W Monocrystalline solar panel for a Campervan can be picked up for around £120 or $150.

How Do I Work Out How Many Campervan Solar Panels I Will Need?

How Do Campervan Solar Panels Work - Calculating Solar Power Demand

In order to work out how many solar panels you are going to need, you are going to have to work out how much power your Campervan requires.

A simple rough way to do this is to go through every item that you are gong to use in your Campervan and write down how much power in Watts it draws.

Once you have these figures, you then need to divide each of them by how often you are going to use them, in hours. This is called the Diversity.

A quick example would be that our Campervan Kettle draws 600W when in use. We boil it roughly 5 times a day, and it takes around 6 minutes to boil. So in total our kettle gets used for 30 minutes a day.

As we need the hourly rate for our calculations we convert 30 minutes into hours, which equals 0.5, then we divide our 0.5 by 24 hours and we get a diversity factor of 0.02. We multiply our Kettle’s demand of 600W by 0.02 and we end up with the estimated demand for the kettle being 12.5W.

We carry out this calculation for every electrical item that we have on the Campervan and we will end up with a total figure.

Let’s say it comes out at 300W in total for ease of calculations. We will then add in a safety margin for errors and additional demands by doubling this figure, upping it to 600W.

So we are going to have to add a sufficient number of solar panels to provide us with 600W. So for our project we would need 4 x 150W Monocrystalline Solar Panels.

As you can see the margin for error that we included in the calculations will give you a lot of spare power capacity if it is ever needed.

What Are The Parts Of A Campervan Solar System?

The makeup of a Campervan solar system is very basic. It consists of just a few essential parts, namely:

  • The Solar Panels
  • The Cables with an In-Line Fuse
  • A Solar Charge Controller
  • Leisure Batteries

This is the basic makeup of all Campervan solar systems. There really is no need to make it more complicated.

Why Does A Solar System Need A Charge Controller?

How Do Campervan Solar Panels Work - Solar Charge Controller

A Solar System needs to have a Charge Controller for it to operate safely. A Charge Controller, sometimes referred to as a Voltage Regulator is required to prevent the Leisure Batteries from becoming drained or overcharged.

A Charge Controller is there to protect your solar charging system from damage, both from over and under voltage, as well as from accepting over and under current. It does so by regulating the Voltage and the Current to exactly what the batteries require at any given time.

What Are The Best Type Of Leisure Batteries For A Campervan?

How Do Campervan Solar Panels Work - LiFePO4 Leisure Battery

Leisure Batteries need to be deep cycle batteries. Deep Cycle Lead Acid Batteries are still widely available, and they will work, but they require maintenance and are bulky and heavy.

Lithium Iron Batteries are a step up in battery technology and require no maintenance. Lithium Iron Batteries are lighter, smaller, more powerful and have deeper cycles that Lead Acid Batteries.

The most effective of Lithium Iron Batteries are the new Lithium Iron Phosphate Batteries LiFePO4, although they can be expensive compared to other types of Leisure Battery.

We need to work out how many Amps of power we need in our Leisure batteries by dividing the theoretical Power demand (600W) of our system, by the system voltage, which in our case is 12V.

This gives us 50 A/h. Again as a margin of error we want to double this figure, so our leisure batteries will have to provide up to 100 A/h.

A single LiFePO4 100 A/h battery would be sufficient for our power demand.

Do I Have To Maintain My Campervan Solar Panels?

Yes, Campervan solar panels work best when they are free from dirt and grime. Regularly cleaning the solar panels on your Campervan will provide you with more charging power than leaving them dirty would.

Other than cleaning them, there isn’t much more that needs to be done.

How Do Campervan Solar Panels Work? – Summary

So in summary, we’ve looked at:

  • Whether solar panels are needed at all.
  • The benefits of having solar panels
  • The Solar Charging System of a Campervan
  • How a Photovoltaic Cell works
  • Types of Solar Panels
  • How much Solar Panels cost
  • How to work out how many Solar Panels you need
  • The parts that make up a Solar Charging System
  • Why we need a Charge Controller
  • Leisure Batteries
  • Solar Charging System Maintenance

I think that covers just about everything to do with how Campervan solar panels work.