How to add solar panels to your boat

Dave Osmolski


For this article, I’ve invited longtime friend and coconspirator, Peter Jenkin, to share his experience adding solar power to his boat. I have known Pete since high school. He’s the only other person ever to ride in my canoe, which leaked in gallons per minute. Former sailors, Pete and his wife, Nancy Miller, now cruise Long Island Sound and coastal New England aboard a 26-foot trawler.

As a new convert to the “dark side,” I had a lot to learn about my new old boat, a 26-foot Nordic Tug. Unlike my old sailboats, it doesn’t have an icebox. Instead, it has a refrigerator like one you’d find in a college dorm room.

We keep the boat on a mooring, anchor out when cruising and never go to marinas. After five to six hours at anchor, the refrigerator would start to die. This happened even with two new group 31 AGM batteries in the house bank. After a few weekends of this, I solved the problem by going solar.

I bought a 160-watt solar panel kit, which included all wiring and a digital controller, and added another 160-watt expansion panel. It’s important to take careful measurements so the panels will fit where you want them and get the maximum sun exposure. If you have a flybridge, you might want to use thin flexible panels and mount them on your canvas. Ditto for sailboats where you can put panels on a Bimini or dodger. With many shapes and sizes to choose from, I was fortunate that my pilothouse roof has room for two 58-by-28.5-inch rigid Go Power solar panels.

My wife and I mounted the panels on the roof of the pilothouse, installed the controller, and got everything working in two half-days. The toughest part was getting the wiring from the roof to the pilothouse interior, inside the paneling.

The kits come with everything you need, but the mounting screws were too long and would have pierced the interior headliner. I bought shorter screws, drilled the hole and bedded the screws in silicone. It takes two people to hide the wiring behind teak paneling, but my boat’s configuration differs from others, so you have to be creative with your particular installation.

This spring I plan to upgrade the refrigerator wiring from 14 to 10 gauge to ensure that I’m not getting any voltage drop via the circuit.

How did it work out? Well, we anchored for five days at Martha’s Vineyard and never bought a bag of ice. By 0600 the refrigerator would cycle off and on as the battery bank’s voltage dropped to about 12.3 volts. By 0900, however, everything was charged and running well. We never lacked for ice cubes at happy hour. Success!

Tips for solar panel installation

Try to calculate the amperage drawn by your electronics. Add them up to see how much power you’ll need.

Investigate the vast array of options in panels. You can find anything from a little panel to keep your battery charged in a runabout to a panel with enough power to run everything on a large gin palace.

Panels made of rigid glass can’t take a lot of abuse and are best mounted where no one will step on them. Flexible panels can be permanently mounted on a dodger or Bimini or moved about as needed. I don’t recommend walking on any of them.

Keep the panels out of the shade as much as possible, as the shaded portion will draw power from the portion in the sun. Some folks set them up so they can be tilted toward the sun for maximum exposure. This gives you better results than laying the panels flat.

When mounting the panels, keep them covered until you hook up all the wiring. They start putting out power immediately, even on cloudy or rainy days.

David H. Osmolski of Charlotte Power Squadron/27 has been repairing boats since high school when his first boat, a canvas-covered canoe with cedar ribs, leaked in gallons per minute and required constant repair.

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