[bhcva]

I would like to mount a solar panel on the bimini, but am concerned that the one or the other of the twin backstays will cast a shadow on the panel most of the day. I'm hoping that there is some expertise or experience out there that might help me understand what I might expect in the way of panel output degradation from this shadowing.

The panel under consideration would be one of the semi-flexible ones such as the Solbian.

Thanks, Bruce

 

[Faster]

Going to be tough to avoid the shadowing, obviously, but can you mount the panel aft of the backstays rather than 'under' the stays? Are you using dinghy davits (another optional location)?

 

[MarkofSeaLife]

Shaddow will be minimal.

 

[bhcva]

Sadly, Ron, the bimini is inboard of the stays....and no davits.

I read an article some time ago written by an 'off the grid' guy who did his own little study of shadowing by installing tall poles adjacent to his solar panel 'garden' and reported that the shadowing effect was quite minimal. So maybe there is hope that the shadowing of those tiny stays will be equally minimal??

 

[denverd0n]

Depends a lot on the type of panels you have, and how they are setup. I recall a study made on a "typical" setup for a cruising boat (I think it was done by Nigel Calder). The numbers were something like... Shade 5% of the panel, lose 40% of the output. Shade 10% of the panel, lose >60% of the output.

Yeah, it can be pretty bad. On the other hand, how often will the panels be shaded, and how much of the output do you really need, day in and day out? You might still be okay, depending on your setup.

Obviously, avoiding any shading is a good thing, if you can accomplish it. If you can't then you need to avoid it as much as possible, and perhaps over-size your solar installation to account for it.

Good luck.

 

[bhcva]

Thanks Denver. I'll try to find that article.

 

[Zacruiser]

Solbian is really way over rated. For the price per watt take a look at Gioco Panels also a high end High Quality Italian manufacturer, with Gioco you're not paying a premium for the name you're getting the same quality panel for 30-40% less. Available in the USA from Bruce Schwab and Canada from Pacific Yacht Systems Pacific Yacht Systems: Marine Electronics And Electrical Systems, Marine Boats Vancouver, Sailboats Vancouver, Boats Electronics

 

[redline]

How thick are your backstays, anyway? I'd expect the shadow of a wire to be a small part of any cell it crosses, and an even smaller part of the entire panel. You don't want to shade a whole cell in a series configuration, but a wire's shadow shouldn't affect too much. The mast, maybe, but not so much a stay.

(I have twin backstays, but the panels are mounted on the arch aft of them. They're between a WiFi antenna, HF antenna (longwire from the arch-mounted tuner to the masthead) and a HF-DSC whip on the other side. Except for the WiFi and its mounting post (originally intended for a Wind Generator, hence the size), the others are all pretty thin shadows.

Or just keep the boat's stern toward the sun and voila, no shading!