Flexible vs Rigid Solar Panels for Boats: Which Should You Choose?

On a boat, choosing a solar panel is less about watts and more about where it will live. A panel that works beautifully on a shed roof can be exactly wrong on a sprayhood. Here is how the three panel types compare afloat, and how to decide.

The three options

Rigid framed panels

Aluminium frame, tempered glass, the classic format. Rigid panels give the best output per pound spent and last 20+ years, but they are heavy, need airflow beneath them, and must be mounted on a flat, strong surface — in practice a stern arch, gantry or coachroof rails. If you have that structure, a rigid panel like our 120W monocrystalline panel with 5m cable is the value choice, and even a 10W trickle charger will keep a starter battery healthy on a swinging mooring all season.

Semi-flexible panels

The marine favourite. A few millimetres thick, a quarter of the weight of glass, and able to follow a gentle curve — a coachroof, a hatch garage, a deck locker lid. Quality matters enormously here: cheap PET-coated panels cloud and crack within a couple of seasons of UV and salt. Ours use ETFE coatings, the same fluoropolymer used on stadium roofs, which shrugs off UV, salt spray and foot traffic. The 120W black semi-flexible ETFE panel is our most popular marine panel, and the fibreglass-reinforced Austrian-made 180W and 330W panels step up the output for liveaboards.

Fully flexible CIGS panels

Thin-film CIGS technology takes flexibility further — these roll over compound curves and bond with self-adhesive backing, no fixings at all. They also handle partial shading better than crystalline panels, a real advantage under a boom or rigging shadow. Our Swedish-made range runs from an 80W low-voltage panel to a 320W panel for serious energy budgets.

How to decide

Ask three questions. Where will it mount? Flat structure with airflow: rigid. Curved deck or coachroof: semi-flexible. Compound curves, canvas or maximum stealth: CIGS. Will it be walked on? Choose reinforced ETFE semi-flexible panels, never glass. What is the budget? Rigid is cheapest per watt; CIGS costs the most but fits where nothing else will.

Installation details that matter at sea

Bring cables through the deck with a proper waterproof cable entry gland rather than a blob of sealant. If you mount a rigid panel on rails, our aluminium mounting brackets keep an air gap underneath, which panels need to stay efficient. And use an MPPT controller — on a boat, where panels rarely sit at the perfect angle, it recovers meaningfully more charge than PWM.

Still weighing it up? Browse the full flexible and semi-flexible range and rigid panels, or tell us about your boat — deck layout, battery bank, how you use her — and we will recommend a setup, no hard sell.