Where to Mount Solar on a Boat: Canvas, Deck, Arch and Rails

Pick the location before you pick the panel. Where a panel lives decides how much shade it sees, whether it can be rigid or must be flexible, how long it will last and how the boat looks from the dock. There are four main options, and most boats with a serious array end up using two of them.

1. Canvas: Bimini and Dodger

Semi-flexible panels built into a bimini or dodger add solar without changing the boat's lines. Panel dimensions are usually the constraint: fitting enough watts for a refrigerator onto a curved bimini takes some puzzle work, and custom-shaped panels can help.

• Attach with adhesive-backed Velcro or zippers. Do not stitch through the panel. Every needle hole is a path for water, and water intrusion is what causes delamination.
• Keep the canvas taut. A panel that flexes and vibrates in the wind develops microcracks in its cells. Snug canvas and a well-secured panel last noticeably longer.
• Protect the canvas from chafe where the panel edges and wiring sit.
• Skip magnets. We have seen magnetically mounted panels leave the boat in high winds.

Panels on canvas see constant flexing, which limits their life whatever their price. Budget panels are often the right call here, especially on canvas that is already mid-life. Choose ETFE over PET either way; see PET vs ETFE vs composite flexible solar panels.

2. Deck, Coach Roof and Hardtop

Walkable semi-flexible panels can go right on the deck. Look for a textured surface and a junction box mounted underneath. The deck is routed to recess the junction box and wiring, and the panel is bedded in sealant, leaving nothing on the surface to catch a toe or a sheet. Because it is a permanent installation, use a premium panel.

For decks and hardtops we prefer custom composite panels from Open Waters Solar. We template the surface and the panel is built to its exact shape, so curved coach roofs and irregular hardtops are fully used. The cells are encapsulated in a composite laminate rather than plastic film, which resists the water intrusion and hazing that end most flexible panels.

On powerboats with a large, open hardtop, rigid panels on mounting feet are also a good choice: the cheapest watts and the longest life. Bring the wiring through a cable gland and keep the panels clear of foot traffic. Panels mounted flat run hot, which costs output; see understanding solar panel specifications for how much.

3. Stern Arch or Davits

An arch or davit mount gives a rigid panel the best sun on the boat, with little shading and a long service life. It also shades the cockpit and protects the dinghy from UV. On a sailboat it is often where the most wattage fits.

• Structure. Panels add weight and a lot of windage. Stern pulpits and older davits often need reinforcement.
• Clearance. Check headroom over the helm and the swim ladder, and how the panels affect boarding.
• Bifacial panels earn their premium here, over a white deck or dinghy. See bifacial solar panels on boats.

4. Rail Wings

A rigid panel on a stainless frame between stanchions adds wattage once canvas and arch space are used up. Hinged clamps let the panel tilt toward the sun or fold in when coming alongside. Rail panels see more shade from sails and heel than an arch mount, and the frame and stanchion bases have to carry the wind load, so check them before you commit.

Check Shading Before You Commit

Walk the boat at mid morning, noon and mid afternoon and watch where the mast, boom, radar and antennas cast shadows. A shadow that crosses one panel for two hours a day can cost more than the panel is worth if it is wired in series with the rest. The Marine Solar Design Guide explains shading and bypass diodes.

Combining Locations

Panels in different places face different directions and see different shade. Wire each location as its own string, often with its own MPPT controller, so a shaded bimini does not drag down a sunny arch. See series vs parallel solar wiring and marine solar wiring, MC4 connectors and fusing. To decide how much array you need first, see how much solar do I need on my boat.

Let Us Design the Layout

Sea & Land Yacht Works designs and installs marine solar from our shop in Wakefield, Rhode Island: canvas integrations, custom composite deck panels, and arches and rail mounts with the structure to carry them. We are the New England master dealer for Open Waters Solar. Call 401-753-7479 or request a consultation.