Solar panel mounting: Deck vs Bimini

[silvercreek]

I'm planning to mount around 150W of solar panels to my 45' monohull sloop rig. I have a small bimini, which could support a flexible long, thin rectangular panel. This is probably the more aesthetic option since the panel would be essentially out of sight.

But I was thinking that instead, I could adhere two square-ish panels to the nonskid on the deck in between the mast and the companionway. I can fit two medium sized panels there, and would keep the weight down low. It also keeps the related electronics closer to the panels with shorter wire runs. And I suspect it may allow me to use semi-rigid panels, which could be more efficient? Is that right?

Thoughts? Anything I'm missing? It's my first foray into solar.

[Kelkara]

I have 100W on my cabin top between mast and companionway, and 100W on my stern rail. In ideal conditions both sets of panels produce about the same amount of electricity ... but the panels on the cabin top are much more affected by shading by the mast and boom, but it doesn't kill their production. The real problem comes when actually sailing, the sails completely shade the cabin top panels on one tack, so there is a real drop in power when the sun is to Leeward.


Your bimini is probably the better location for gathering sunlight.

[Ryban]

Fleixible panels in general have short lives compared to rigid panels. You should consider partial shading factors in both locations as well as whether the deck-top ones will need to be walked-on.

I don't really trust any panels that are stepped on regularly to last very long. Partial shading of most panels, even the smallest fraction, from say your boom, will basically eliminate all power from that panel as well.

If it were me, and depending on your bimini construction, I'd opt for rigid panels up there, with stainless tubing supporting spanwise. This would also add rigidity to the bimini, but you'll need to figure out pass-throughs that you can keep water tight.