Fitting a solar panel to a caravan: things you need to know!

Difficulty: 4/5 (requires wiring and drilling through the caravan roof)

Tools: Drill and bits, screwdrivers, wire strippers, wire cutters, crimping tool, tape measure, adhesive, and gun

Total project time: Six hours, excluding adhesive curing time

Solar power basics

I did some research before choosing and buying the kit for this project and made my decisions on the following basis:

● Monocrystalline panels are more efficient than polycrystalline or thin-film ones but are more expensive as a result.

● I mounted the panel with an air gap under it to allow cooling, as heat reduces efficiency.

● Ideally, the panel should be aimed due south and angled at 30-40° but I chose to mount mine flat on the roof and it works well enough.

● Panels can generally be 12V or 18V, which is why a charge controller is essential. Mine is an 18V 100W panel, meaning the maximum (theoretical) current is 5.5A.

● The charge controller makes sure the battery gets 12V irrespective of the panel’s output voltage. There are two kinds – MPPT (maximum power point tracking) and PWM (pulse width modulation).

● MPPT controllers are more efficient and offer greater functionality but are more expensive as a result – I chose MPPT.

● Solar panels can be connected to increase either output voltage (in parallel) or current (in series).

● The plugs in the battery compartment are intended to allow another panel to connect in series in case the caravan is parked under trees, for example.

● I used a 25A cable to give capacity in case I wanted to add another similar panel on the roof or a supplementary panel plugged into the battery compartment plugs.

If you’re not comfortable with either wiring or drilling holes in the outer skin of your caravan (you have to get a cable in somehow), then there are plenty of professionals who will do this job for you.