The Offshore Voyaging Reference Site

Portable Solar Panels For Cruisers

The good folks over at Ocean Planet Energy are selling these foldable and portable solar panels.

A couple of these will provide a cruising boat with around 100 amp hours at 12 volts over the course of a reasonably sunny day at anchor.

To me this is a way better idea, at least to supplement a reasonable number of fixed panels, a good cruiser’s alternator, and possibly a hydro-generator for offshore use, than festooning a boat with a huge unseamanlike fixed solar array.

Might even get one of these for our J/109, and I also think this, or something like it, could be a great solution for many Adventure 40 owners.

Inline Feedbacks
View all comments
Neil McCubbin

Our 150 watt panel, installed horizontally above the Bimini with no shade, give us a maximum of 30 Amp-hours per day here at 15 deg North

Eric Klem

Hi Neil,

I am a little surprised by how low an output you are recording unless you only cruise in the short days of winter, you are 24V or something. We have an older Kyocera 140W panel with ±30° manual tilting capability through a Victron MPPT controller and on normal sunny summer days average around 60 Ah at 12V nominal and have peaked a little over 70 Ah in a single day near the summer solstice. We are located at 42N so on average should have less solar potential than you.

Have you read the max current coming from the panel on a perfectly clear sunny day with the sun directly overhead? If you are not seeing right around the panel’s rating, then something is wrong. A tiny bit of shading such as a backstay can provide a shocking drop in output and I know several people who have thought there was a panel problem when instead they had something like a spare halyard tied off in a bad way. Since you mention the panel is above the bimini, if it is a flexible panel and has been flexed too much, it may well be damaged and not really putting out. One other thought is that there are plenty of apps and online calculators that let you plug in all your parameters and they pull the climate data and give you a predicted output assuming you are not load limited so you could check one of those against your real world numbers.


Drew Frye

Why would you not install a semi-flexible panel in the same location? I bet lunch it produces more power because it will be exposed for 3 times more hours, because you don’t have to fool with it or forget to put it out.

Yup, I like hard panels, but unless you have a big hardtop (cruising cats) using deck space with semi-flexible panels makes a lot of sense. I installed a semi-flexible panel on the companionway turtle several years ago, and while it sees some shading, it is there, making power, all day. I would also bet it will last as long because it will see less flexing and handling (flexing is the leading cause of death of Bimini panels–micro cracking of the cells).

Charles Roberts

Do you have a recommendation connecting these folding panels to your house banks for charging? Especially if you might want to move them to different locations throughout the day?

We have one that’s used to charge our electric outboard battery and laptops but I couldn’t figure out a reasonable way to direct the power to the house bank. Likely I’m missing something obvious and would love a hint!