Solar panels are an increasingly attractive option for canal boater.
A basic system offering 100 watts of around 5 amps charge can be purchased from around £150. However you could look to install a solar system to run your full system, providing you have the budget and space to do so!
A consideration is the mounting of the panels on the roof as with everything canal boat, space is at a premium. As technology improves so do the efficiencies of photo-voltaic panels. The technology is becoming more suitable for the northern European climate and sizes are reducing.
In simple terms you will require the following equipment: Solar panel/s, charge controller and batteries. Installation is simple with mountings often supplied as kits for DIY installation. Wire connections are made waterproof plug in connectors known as MC4 connectors. It is simply a question of wiring the charge control unit to the battery bank then connecting the panel or panels to the controller. As with other items on your canal boat, it is imperative to ensure your solar panels are secure from any opportunists trying to grab a freebie!
Controllers are available that can charge multiple banks of batteries.
DC panels typically operate from around 17 volts and upwards. Chargers control and regulate the input into the battery bank and panels can be wired in parallel to increase wattage output. For example, two 100 watt panels can be wired to make one panel of 200 watts. The voltage output remains the same, at whatever the panel is rated at but using our W / V = A equation the combined output rises from a theoretical 7.9 amps to nearly 16 amps. In reality this will be closer to an average of 10 to 13 amps but the advantages of “stringing” panels is clear.
It has to be said that the reality of solar charging can be quite different to the theory. As much as 60% improvement in panel output can be gained under certain conditions by angling the panels towards the sun. This is not always possible on the windy canals. Also panels, obviously, need direct sunlight to function efficiently. In direct sunlight, in the heat of high summer, a steel canal boat can be an uncomfortable place. You will find yourself cruising past those nice cool shady spots to moor in the sun.
The quality of construction of the solar panel, as well as the cell type, will directly impact the amount of power a panel will produce. There are two cell types: mono crystalline (usually black in appearance) or polycrystalline (usually have a blue tint appearance). Mono crystalline cells tend to be more efficient and are able to produce more power in poor light conditions.
Autumn, winter and spring will see dramatically less output from your panels than in the height of summer. Be prepared to see little or no output on many days in these seasons in the northern hemisphere.
Consider a 200watt kit as a minimum for running a fridge, lights, pump and TV.
Solar panels are a method of charging. Some charge controllers do have an ability to run an appliance such as a light or low power pump from any excess charge voltage but this is limited. Best practice and safety dictate that appliances should be wired and run from the conventional DC system.