Solar panels are one of the best upgrades you can make to a campervan. They give you free, silent power wherever you park, reduce your reliance on campsites with electric hookup, and extend the time you can spend off-grid. But choosing the right setup and installing it properly is important. Here is what you need to know.
How Much Solar Do You Need?
The amount of solar you need depends on how much power you use. A basic setup with LED lights, phone charging, and a small fridge might use 30 to 50 amp-hours per day. A more comprehensive setup with a laptop, diesel heater, water pump, and TV could use 80 to 120 amp-hours per day.
In the UK, a 100W solar panel will produce roughly 30 to 40 amp-hours per day in summer and 10 to 15 amp-hours per day in winter. So for a basic setup, a single 100W panel might be enough in summer but will struggle in winter. For most campervans, we recommend 200W to 400W of solar as a good balance between output and roof space.
Types of Solar Panel
There are three main types of solar panel used on campervans. Monocrystalline panels are the most efficient and produce the most power per square metre — these are what we recommend for most installations. Polycrystalline panels are slightly cheaper but less efficient, so you need more roof space for the same output. Flexible panels are lightweight and can conform to curved roof surfaces, but they are less durable and tend to lose efficiency faster than rigid panels.
Charge Controllers: PWM vs MPPT
The charge controller sits between your solar panels and your battery and regulates the charging. There are two types: PWM (Pulse Width Modulation) and MPPT (Maximum Power Point Tracking). PWM controllers are cheaper but waste some of the panel's potential output. MPPT controllers are more expensive but extract significantly more power from the panels — typically 20 to 30 percent more. For any system over 100W, an MPPT controller is worth the extra cost.
Installation Considerations
Mounting solar panels on a campervan roof requires careful planning. You need to consider the position of roof vents, skylights, and any pop-top mechanism. Panels should be mounted with a small air gap underneath to allow cooling — hot panels are less efficient. Cable entry points must be properly sealed to prevent water ingress.
We use marine-grade cable glands and sealant for all our installations at AVS Bransgore. A poorly sealed cable entry is one of the most common causes of roof leaks in campervans, and it is completely avoidable with the right materials and technique.
Battery Compatibility
Solar panels work with any type of leisure battery, but the type of battery affects how well the system performs. Lead-acid batteries (including AGM and gel) are cheaper but heavier and can only be discharged to about 50 percent without damage. Lithium (LiFePO4) batteries are more expensive but lighter, can be discharged to 80 or 90 percent, charge faster, and last much longer.
If you are investing in a decent solar setup, a lithium battery is worth considering. The higher upfront cost is offset by the longer lifespan and better performance.
What We Offer
At AVS Bransgore, we supply and fit complete solar systems for campervans. Our packages include the panels, MPPT charge controller, wiring, fuse box, and professional installation. We can also integrate solar into an existing 12V system or design a complete electrical package from scratch. Prices start from around 500 pounds for a basic 100W setup, with larger systems priced according to specification. Call us on 01425 200826 for a quote.
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