Flexible Solar Panels on Dodger and Bimini

[Neptune's Gear]

I have, and have had for over 10 years, two semi flexible panels on the Bimini canvas. No issues at all, even in strong conditions, and offshore. Recently replaced the old 72w panels with 120w ones. They have Velcro glued to the underside, and the other 1/2 of the Velcro sewed to the Bimini canvas directly. Over centre toggles In The corners, but not really required. Velcro ALL the way around - you can't afford for the wind to get underneath...


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[Obi Wan]

I mounted a flexible 100w panel on my Bimini - was going to be temporary but it's been 6 months and I don't see a reason to take it off until I take the Bimini down in the winter. I just tied the corners to the frame of the Bimini. I haven't noticed any wear problems and my Bimini doesn't really flex much because I have it pretty tight. I bought a couple of fold-up soft solar panels before this and they didn't last more than a few weeks.

For me the advantage of the flexible panels is not just the flexibility (and they are only slightly flexible, which is good) but that they weigh so much less than the glass-covered, framed ones.

[Elie]

I have installed two 100 watts semi flexible solar pannels on my bimini, attached with velcro flaps. The installation is neat, but after two years I have to replace the velcro side attached to the solar pannels(deteriorated by UV ?). It is not an ideal position sun wise, because the boom, radar mast or mast always somehow project shadows. But still, I can get an average of 3-4 amps all day long. I have them supplemented by a large(275w) rigid solar pannel installed on deck aft of the mast. Surprinsingly, almost no shadow from the boom(sun angle is too low at our lattitude, and very little from the mast. all the pannel are connected in serie through a very efficient MPPT controler, and the result is good enough: No more engine runing, even in northen Vermont. MPPT controllers do a good job of maximazing power output from sunup to sunset, because as long as there is voltage over 13 volt(On 48 v for the complete array) some watts flows to the batteries.

[PolarisOne]

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[HappyMdRSailor]

Originally Posted by PolarisOne

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Welcome to CF Polaris!

[Tessellate]

Anyone have further tips on how to attach flexible panels to a bimini?
I've heard recommendations to not install the flexible panels over any tubing support points (hard spots) in the bimini. But biminis typically have a cross-bar in the middle to support the middle of the bimini. If I don't install over that I can only fit one 100W panel. If I install over it I can fit 2 100W panels (running fore-aft lengthwise).

It seems like the crossbar wouldn't damage the panel. It doesn't push up hard, it's just there to prevent the bimini from collapsing into a concave puddle collector. Anyone installed over a crossbar? And did you do with or without a backing board? What kind of backing board if so?

Also any tips on the attachment method? It seems many people do velcro but then complain the velcro had quick UV deterioration. Why not just do 6 rivet / clasps (4 corners + 2 in middle on the long edge)? One person worried wind could catch under that, but that seems unlikely if you make it properly taut?

[eMarineSystems]

We sold plenty of flexible panels, which most of wind up mounted on top of Bimini's. The problem that one encounters with flexible panels is that they are constantly flexing on the top of the Bimini if there is no backer board put in place to protect it. The constant flexing over time eventually causes the electrical connections to the solar cells to fracture and the panel will stop operating. Most manufacturers will not warranty their product when installed like this. Flexible panels are designed to go onto a curved firm surface and not one that is flexing all the time.

Typical backer boards that users have our twin core, 8mm poly carbonate panels, the material typically found in use on greenhouse's. The channels provide an opportunity for airflow beneath the panel causing them to operate more efficiently

[Wainui]

I have just got back from 6 months in Mexico with 2 x 100w flexible panels on my Bimini which go across a center strut. No problems even in 30 + knots. I attached them using from the bottom a #10 x 3/4" machine screw, fender washer, leather circle top and bottom, fender washer, thin nut, solar panel, small washer and a acorn nut. I got the panels on amazon for about $170 each. I'm adding another one next time.

[Tessellate]

Thanks eMarine. I've been looking at your site too and I think a backing board makes sense for longevity. Edited: I realized you sell 2 types of backing boards. The 8mm ones are just shy of 3/8" though (5/16"). My concern is it doesn't look like they would really flex? So I'd be turning a semi-flexible solar panel into a mostly rigid panel? If I can't bend the backing board a bit to the curvature of the bimini, I don't understand how that would work (it would catch wind more).

Also with a 5/16" - 3/8" backer it increases the total thickness by ~3x (from less than 1/8") and weight by 4 lbs (the 4 lb backer is actually heavier than the 3.3 lb 100W panel). (The weight of the 8mm backer isn't listed - I'm guessing it's a little lighter?)
So now that I've doubled the weight and created thicker corners on a mostly rigid platform, it seems now I'd need to pad the corners (ex, wrap in canvas) to prevent them from poking through the bimini in short order.

Wainui, looks like you used no backer, but only have had them 6 months. So time will tell how long they last. My goal is at least 5 years. The machine screw technique is neat, I guess the compression of the leather and fender washers helps distribute the tension a bit so that the bolts don't elongate the holes in the canvas.

[brianc]

Originally Posted by Sailor647

We went with ridged on the bimini. Two separate systems for redundancy. Each system has two panels, its own controller, and is connected to separate battery banks.

We also reinforced the bimini structure to make sure the panels were supported properly and could withstand the wind.

That is a good looking install. I have been looking for ideas to create a "low profile" mounting system for flexible panels, this is along the lines of what I was thinking.

[Nefta]

If you finally decide on large rigid panels, you may be interested in mounting a stern arch. There is a modular model, it adapts to all boats, there are many configuration options and it is installed without welding with basic tools. And the panels are tiltable towards the sun:
https://www.autocazantes.com/en-gb/portiques-3/