If you’re going off-grid with your converted campervan you’ll need to consider how to generate power in your van when you don’t have access to an electricity source.
One of the most common methods is installing solar panels. The main benefit of installing solar panels is that any energy you generate is free.
Should I install solar panels?
When choosing panels for your van or mobile installations consider these three main factors.
Solar panel efficiency is crucial, but the most efficient panels are often large and difficult to install. When you have van weight requirements to meet, you need to ensure your solar panels are lightweight.
If you don’t have experience installing solar panels, get panels that are easy to install. And even if you have experience, an easy install is always better than a complicated one!
What are the different types of solar panels?
We’ll start by examining various types of solar panels, comparing traditional rigid panels, semi-flexible panels, and semi-rigid walkable solar panels. We have firsthand experience with all three types, and we’ll recommend our favoured type at the end of the article.
1. Rigid solar panels
Crystalline silicon cells are common in the construction of rigid solar panels, usually referred to as conventional or crystalline solar panels. The longevity and effectiveness of these panels are well-known.
These panels are the largest of the three, usually consisting of an aluminium frame and a glass top. When selecting stiff panels, keep the following points in mind:
Construction and Durability
The strong frame of rigid panels, which is often composed of aluminium, gives the solar cells structural support and protection.
Fixed panels are more resilient and less vulnerable to damage from outside sources like hail or debris because of their sturdy build.
Opposed to their flexible counterparts, rigid panels may convert more sunlight into electricity because of greater efficiency rates.
Greater efficiency qualifies them for installations on rooftops or open fields, for example, when space is not an issue.
In traditional solar installations, rigid panels are often installed on tracking systems or stationary structures.
Installing a van build or mobile application can be more challenging because you have to fasten the heavy panel correctly. The most effective method is with a roof rack, which may get pricey quickly.
Weight and size
The weight and bulkiness of rigid panels compared to their flexible counterparts can affect the load-bearing capability of structures and the cost of transportation.
2. Semi-flexible solar panels
Conversely, semi-flexible solar panels are more surface-adaptable. They can be installed on a vehicle roof easily and with less drag because they can be installed nearly flat. Here are some important things to take into account while using semi-flexible solar panels, as they do have some disadvantages:
Thin-film solar cells create semi-flexible panels, which have some bending flexibility. They are appropriate for installations requiring flexibility or curved surfaces. A curved van roof like a Sprinter, Transit, or Promaster provides a rare opportunity to install your solar panels with almost no extra height added.
The drawback is that the panels will deteriorate over time more quickly the more twisted they are. As a result, more care may be needed during installation to guarantee that the panels are not bent excessively, which could damage their effectiveness.
Semi-flexible panels are substantially lighter than rigid panels, making them more appropriate for automotive applications where weight is a consideration. You might be surprised to learn that every van on the market has ratings for general weight and roof capacity!
Semi-flexible panels can tolerate bending, but over time, especially in severe environments, they could be more prone to wear and tear than rigid panels.
Although flexible solar panels offer numerous advantages, one of the biggest drawbacks is their efficiency compared to rigid solar panels.
3. Semi-rigid walkable solar panels
Walkable, semi-rigid solar panels are last but most definitely not least. These panels are our top choice for versatile, simple-to-install solar power. When it comes to semi-rigid panels, keep the following in mind:
While semi-rigid panels can bend, they do so considerably less so than semi-flexible panels. These panels can be fitted to the shape of a van roof; however, they will not work with any angle more dramatic than a few degrees.
Because of the aluminium backing panel, they have a 1/4-inch thickness. Because of this, they are also marginally heavier than flexible solar panels, but they are still far lighter and easier to handle than rigid solar panels. The profile from the side is low because they are so thin. Opposed to a hard panel, they keep your van less detectable.
Under the right circumstances, semi-rigid solar panels can be effective compared to rigid and semi-flexible panels. In terms of effectiveness, they fall in the middle of the two other possibilities, but they ultimately resemble rigid panels more than semi-flexible ones.
The simplicity of installation is arguably one of the best aspects of these panels. You can purchase a C channel and VHB tape it to the van roof. Installing solar panels on a van roof requires no metal, screws, or complicated roof racks. Furthermore, they are simple to swap out!
Durability is another advantage of semi-rigid panels versus semi-flexible panels. These panels are very sturdy and are resistant to cracking and premature ageing.
These panels are by far the priciest. However, when you add the decking, roof rack, and other materials to the price, you could save yourself money.
How to wire solar panels in a campervan
If your array consists of more than one panel, your next thought after selecting the panels will be how to wire them. There are three methods for connecting several solar panels: parallel, series and parallel series.
A parallel is a branch that joins the positive and negative sides into separate lines. It’s arguably the simplest and might be what you have observed other people doing with their builds. However, that does not imply that it is the ideal configuration.
The primary drawback of this approach is that adding more panels will cause the amperage to rise gradually, based on the panels’ capacities. To retain the correct ampacity, you will need to make the appropriate wiring adjustments.
2. Series wiring
On the other hand, series wiring gradually raises voltage over amperage, allowing the solar wiring to carry fewer amps while still producing the same amount of power. One huge panel with a single negative and single positive on either side of the solar array is created by series wiring, which is achieved by connecting the positive of one panel to the negative of another.
The drawback of series wiring is that, since you are effectively building one big panel, any shading of one of your panels will impact the entire array, causing a reduction in efficiency. This approach requires an MPPT-compatible charge controller as well, depending on the number of panels in the series.
The last kind of solar wiring is termed series-parallel. As there isn’t much room for panels on van roofs, this type of wiring suits larger solar arrays. The positive and negative of half the panels connect in series for this sort of wiring, which requires an even number of panels. Both series branch together in parallel. Age and amperage are both increased with this system. However, if one solar panel is shaded, the shading power loss will only occur across half of the system.
Saving money with wiring
You can see how different wiring methods might impact the total amount of wiring in a given configuration. In electrical installations, wiring is sometimes one of the most costly and neglected components. You could save a tonne of money just by deciding to wire your solar panels differently!
Which campervan solar panels should you pick?
The Semi-Ridgid panels take the win! Each of these panels has different pros and cons, and other applications may be better for your van.
Stay away from the semi-flexible panels altogether. While they are cheap and seem appealing for all different mounting applications, their efficiency and longevity are questionable.
The best application for semi-flexible panels is an additional array that you can hang or plug in, but that isn’t permanently mounted to your vehicle.
For mounting panels, we recommend that you do not drill holes directly into the roof since it will inevitably become a failure point where water and debris can enter the vehicle. Instead, use a roof rack or VHB tape, or we have even heard of some applications that use extremely strong magnets to attach solar panels (we have never tested this ourselves).
This is again one of our reasons for choosing the semi-rigid panels since the installation is fairly minimal and requires no drilling or compromising of the vehicle roof.
We hope this guide leaves you with a better idea of how to pick solar panels and wire a van. And if you need any advice, we can help you!