WHAT IS NECESSARY FOR A COMPLETE SYSTEM?
A panel needs a charge controller to convert the voltage of the panels into the correct charging voltage of the batteries. To get maximum efficiency from the total system, the application of MPPT (maximum power point tracking) controllers are advised. These controllers have been specifically developed for solar panels. The incidence of light on the panels often differs greatly (certainly on a boat with shade from a mast or sail, for example) and with that also the voltage that the panels issue. The MPPT regulators measure the current voltage on the panels every 1.5 seconds and adjust accordingly such that as much current as possible is flowing to the batteries at any given time. Such a charge regulator is typically mounted at the battery bank and adjusted to the type, voltage and power of the battery. With the charge controllers you have the option to connect a display which currently shows the yield of the panels and the status of the battery. These can be mounted in the cabin or wheelhouse and connected to the controller with a UTP cable. In addition to the controller, cables and the necessary contacts are of course required. Most panels come with a flat (Flush) cable on the back of the panel. This enables an elegant integration on deck. We also sell panels with MC4 contacts. These contacts are the standard in the solar industry, have a low resistance, are extremely durable and waterproof. Check out the panels with a junction box.
HOW DO I CALCULATE WHAT IS SUITABLE FOR MY SYSTEM?
I want to install 2 times 100W panels. What kind of charge controller do I need? The three most important factors in this calculation: – The voltage on board – The total power of the panels – The capacity of the charge controller The following also applies here: power = voltage x current,
or P = V x A. Th choice for the correct charge controller is based on the peak current of the panels. Two 50W panels will deliver a maximum of 8.33 amperes (100W / 12V) on a 12V on-board system, so a 10A charge controller is sufficient. With two 100w panels and a 12V system, this will be 16.66 amps and a 20a charge regulator is therefore required. Of course you can also mount two 10A charge regulators; one for each panel. This will improve efficiency because the charge controller can measure the voltage of the panel more accurately. The new MPPT charge controllers are based on the Wp of the panels and therefore don’t require these calculations anymore.
WHAT is the yield of a system?
Solar panels are offered in the peak wattage (Wp) they can deliver, which is the power in full sun. To give a good estimate of the average performance in the Netherlands, you can roughly divide the peak wattage by two. A 100Wp panel will therefore deliver an average of 50w over the hours that light falls on it. In winter this is an average of 6 hours, in summer 10 hours. With a 12 volt system, that average 50w will deliver a little more than 4 amps (power = voltage x current). In the summer, a 100Wp panel can add an average of 40Ah to battery capacity, with a day with strong sunlight this can go up to 60Ah.
WHAT ARE THE CONNECTION OPTIONS?
It is possible to connect multiple panels to a charge controller, provided they have approximately the same voltage (see specifications). There are two options: – When the panels are connected in series, the amperage remains the same but the voltage is increased. Only solar panels with the same amperage can be connected in series. A disadvantage of this method of switching is that if shadow falls on one of the panels, the efficiency of the total system drops. – When the panels are connected in parallel, the amperage goes up but the voltage remains the same. This option is therefore only possible with panels of the same voltage. The advantage is that if a panel is in the shade, this does not have a strong negative effect on the performance of the other panels in the system.
Do you need more help with attaching your solar panels? Watch the instructional video below where everything is explained step by step