Hanse 531 – 137Wp SP series

Custom-made 137Wp SP series solar panel for a Hanse 531, using three bypass diodes and an optimized string layout for maximum shade tolerance.

Apart from sprayhood and bimini the companionway hatch is a very good place for the integration of solar panels, as long as the shadow from the boom is considered in the planning process. At most times of the day at least a part of the system will be covered by this structure, leading to energy losses in a standard photovoltaic system.

To optimize the energy yield, we have not only put the strings in parallel to the boom but added three bypass diodes, which allow us to bridge shaded parts. This was combined with a special step-up MPPT charge controller, which is able to even make use of the remaining third of cells if two thirds are covered or in shadow. It optimizes the panel voltage 15 times per second and boosts it to a temperature-compensated charge voltage for the battery.

Installation was done with our proven pre-mounted adhesive, not only saving a lot of time but also resulting in a walkable surface with optimum distribution of mechanical force. Wiring was done invisibly, with a waterproof feed-through directly below the panels. The structural frontsheet makes sure the crew can safely work on the surface in boat shoes, even in wet conditions.

137Wp deliver around 20-30Ah per day at 26V – enough energy to run a fridge. This additional energy source allows the owner of this Hanse 531 to spend more than a day at anchor without the need to start the engine for charging. As an extra, it keeps the batteries topped up and in perfect health over the winter, even though the marina doesn’t allow the shore power cord to remain plugged in when nobody is onboard.

Technical data:
Power: 137Wp
Panel series: SP
Weight: 2kg
Battery voltage: 24V
Battery type: AGM