Solar panel strength and mounting

[Muaddib1116]

I am going to put two large rigid solar panels (Trina TSM-365-DE06X.05-II 365Watt) on top of my bimini.

https://webosolar.com/product/trina-...ono-all-black/

This site says that 3.5x6ft panels can withstand a snow load of 5400Pa, which is approx. 112lbs/sqft. and a wind load of 2400Pa which is approx. 50lbs/sqft.

My plan is to mount them lengthwise fore and aft, side by side, on top of the bimini, clamped at the corners to two athwartship 1" stainless tubes that I'll mount to the front and back bows of the bimini. So the 6ft span will be supported by the integral frame of the solar panel.

These panels are about 44lbs each and with the tubing and brackets I'm already planning on using, I estimate that I'll be adding almost 100lbs to the top of the bimini, so I'm hesitant to add a 3rd stainless tube in the middle. Do you think the panels are strong enough to only be supported at the corners? If flex is the biggest concern, maybe I could epoxy aluminum angle strips to the back of the panels, rather than adding more steel tubing. Any thoughts?

[rslifkin]

My slightly larger panels (also made by Trina) are mounted just using the 4 provided mounting holes. They're not at the corners, but about 12" in from each end on the long sides. It hasn't been any issue so far.

[Muaddib1116]

Great, thanks for feedback! I'm hoping to just use the corners so that I can prevent the panels from overhanging the front and back of the bimini without creating a whole mess of additional tubing on top. I am buying these brackets to mount in each corner, with hinged clamps bolted to the flats. Additionally, by only having mounts in the corners, I can access all the clamps without taking the canvas down, in case I want to remove the panels quickly.

https://www.amazon.com/dp/B07P8DNMPD

I also found this product data sheet, which shows the cross sections of the aluminum frames.

https://www.solarflexion.com/v/vspfi...Data_Sheet.pdf

The double walled frames look like they should be pretty strong and stiff, and the glass is 3.2m (1/8") tempered glass.

Are your panels also mounted on top of your bimini?

[rslifkin]

Originally Posted by Muaddib1116

Great, thanks for feedback! I'm hoping to just use the corners so that I can prevent the panels from overhanging the front and back of the bimini without creating a whole mess of additional tubing on top. I am buying these brackets to mount in each corner, with hinged clamps bolted to the flats. Additionally, by only having mounts in the corners, I can access all the clamps without taking the canvas down, in case I want to remove the panels quickly.

https://www.amazon.com/dp/B07P8DNMPD

I also found this product data sheet, which shows the cross sections of the aluminum frames.

https://www.solarflexion.com/v/vspfi...Data_Sheet.pdf

The double walled frames look like they should be pretty strong and stiff, and the glass is 3.2m (1/8") tempered glass.

Are your panels also mounted on top of your bimini?

That design makes sense to me.

Mine are mounted to the cabin top, not the bimini, however. See pictures below for the mounts before and after putting the panels on them.

[Muaddib1116]

Thanks! I'll go ahead with my plan, and if there's issues, I'll come up with a way to add support.

[dksail]

We mounted a 72 cell 310 watt panel at the ends and it sagged in the middle. The product instructions are clear that they need to be mounted about 12" from the ends. I ended up supporting the panel length with a light weight aluminum channel.

[flightlead404]

Originally Posted by Muaddib1116

I am going to put two large rigid solar panels (Trina TSM-365-DE06X.05-II 365Watt) on top of my bimini.

https://webosolar.com/product/trina-...ono-all-black/

This site says that 3.5x6ft panels can withstand a snow load of 5400Pa, which is approx. 112lbs/sqft. and a wind load of 2400Pa which is approx. 50lbs/sqft.

My plan is to mount them lengthwise fore and aft, side by side, on top of the bimini, clamped at the corners to two athwartship 1" stainless tubes that I'll mount to the front and back bows of the bimini. So the 6ft span will be supported by the integral frame of the solar panel.

These panels are about 44lbs each and with the tubing and brackets I'm already planning on using, I estimate that I'll be adding almost 100lbs to the top of the bimini, so I'm hesitant to add a 3rd stainless tube in the middle. Do you think the panels are strong enough to only be supported at the corners? If flex is the biggest concern, maybe I could epoxy aluminum angle strips to the back of the panels, rather than adding more steel tubing. Any thoughts?

I just went through this is 3 x 26lb panels and 1" 16ga 316L tubing. That tubing is not as stiff as you might imagine over a 6' span. In my case, from end to end across my bimini (hunter 38), its around 96" from memory. There is definite sag in the middle.

To combat this I used a few techniques. First, the rear end of my panels overhangs my davits which have a two pretty rigid port/starboard 1.5" tubes around a foot apart. So I used 4 short tubes with T's to connect my rearmost panel mounting tube to the davits making triangles. This prevents sag and also makes that part of the frame rigid and resistant to fore/aft motion.

Second, I used a 3rd cross tube about 1/4 down the panel. So, the foremost cross tube is close to the panels leading edge. The 2nd tube about a 1/4 down the panel, and the 3rd very rigid tube right at the panel training edge.

Third, I put a little "pre-bend" in the front two tubes before bolting the panels to it. This helped but even with all of that, there's still a little sag.

[MJH]

Originally Posted by Muaddib1116

I am going to put two large rigid solar panels (Trina TSM-365-DE06X.05-II 365Watt) on top of my bimini.

https://webosolar.com/product/trina-...ono-all-black/

This site says that 3.5x6ft panels can withstand a snow load of 5400Pa, which is approx. 112lbs/sqft. and a wind load of 2400Pa which is approx. 50lbs/sqft.

My plan is to mount them lengthwise fore and aft, side by side, on top of the bimini, clamped at the corners to two athwartship 1" stainless tubes that I'll mount to the front and back bows of the bimini. So the 6ft span will be supported by the integral frame of the solar panel.

These panels are about 44lbs each and with the tubing and brackets I'm already planning on using, I estimate that I'll be adding almost 100lbs to the top of the bimini, so I'm hesitant to add a 3rd stainless tube in the middle. Do you think the panels are strong enough to only be supported at the corners? If flex is the biggest concern, maybe I could epoxy aluminum angle strips to the back of the panels, rather than adding more steel tubing. Any thoughts?

I installed two 59.1Lx26.3W" (27.5 lbs. each) Kyocera panels on top of my renewed dodger in 2015 prior to a 2016 roundtrip to Hawaii. Used two longitudinal s.s. tubes on top of the dodger for each panel. Panels used two s.s. horizontal crossing tubes connections about 1/3rd of the distance down/up each side of a solar panel to spread the load...I have little concern for snow in my area.

At the same time I also installed matching panels on a new s.s. arch off the stern with the same install system. Total of 4x140W=560W.

No install issues noted to date.

~ ~ _/) ~ ~ MJH

[Redline452]

My three Kyocera 130s are mounted on a stainless L-bracket frame above the stern arch, all made by the arch manufacturer - Métaux Produits D.T. Inc of Grand Mere, Quebec. The whole assembly is rather (I'd almost say incredibly) heavy but very solid, and can tilt fore-and-aft (that's just how they make them, not absolutely necessary but I can tilt them a couple of degrees down aft to shed rain away from the bimini and farther forward to catch the sun during winter storage (usually south-facing in the yard). As I recall it took three of us to lift the panel+frame assembly into place while the boat was in the (fortunately just enough lower) TraveLift bay.

No way would the bimini have been strong enough to support that, even had the frame been lighter aluminum.

[Nicholson58]

We installed three Sanyo 220 HT panels above the Bimini. There was only the light bows for the canvas. I made a welded aluminum frame which also houses the wire ways. This frame is mounted on SS tube supports I fitted above the main traveler forward and two rear tube supports cantilevered from the boom gallows. At first, the aluminum frame was too bouncy due to the span so I added a 1/2 X 4 inch aluminum bar up on edge to the forward and aft ends of the aluminum frame. I can stand on it now. The support tube over the main electrical cabinet was made extra large and the wires enter the boat here.

In the photos the Bimini is down for hurricane storage. Normally the Bimini is close to the framing

[Rohan]

Originally Posted by Muaddib1116

These panels are about 44lbs each and with the tubing and brackets I'm already planning on using, I estimate that I'll be adding almost 100lbs to the top of the bimini,

100 lbs is no joke! Consider flexible panels instead. I installed mine on the bimini using strong velcro strips, all of them parallel to allow air flow underneath. It works well and barely weighs anything.



I know some people here hate flexible panels, but the ones that are made today are generally much better quality than the ones made years ago.

[Muaddib1116]

Originally Posted by dksail

We mounted a 72 cell 310 watt panel at the ends and it sagged in the middle. The product instructions are clear that they need to be mounted about 12" from the ends. I ended up supporting the panel length with a light weight aluminum channel.

Originally Posted by flightlead404

I just went through this is 3 x 26lb panels and 1" 16ga 316L tubing. That tubing is not as stiff as you might imagine over a 6' span. In my case, from end to end across my bimini (hunter 38), its around 96" from memory. There is definite sag in the middle.

To combat this I used a few techniques. First, the rear end of my panels overhangs my davits which have a two pretty rigid port/starboard 1.5" tubes around a foot apart. So I used 4 short tubes with T's to connect my rearmost panel mounting tube to the davits making triangles. This prevents sag and also makes that part of the frame rigid and resistant to fore/aft motion.

Second, I used a 3rd cross tube about 1/4 down the panel. So, the foremost cross tube is close to the panels leading edge. The 2nd tube about a 1/4 down the panel, and the 3rd very rigid tube right at the panel training edge.

Third, I put a little "pre-bend" in the front two tubes before bolting the panels to it. This helped but even with all of that, there's still a little sag.

I'm honestly a little surprised that sagging under it's own weight is an issue given the amount of snow they're designed to withstand on a residential roof. My concern was mostly for dynamic flex from wind and bouncing cracking the glass. What type of panels do you guys have? When were they made?


My hope was to use the panel itself as part of the structure, to save weight. I think I'll mount them the way I'm currently planning, and if I decide I need support in the middle, I can add a third athwartship tube across the middle of the panels. If the bimini frame ends up needing reinforcement, I'll figure that out.

All of the high efficiency flexible panels I found were crazy expensive, at least $600 for 100W. I figured I'd give the heavy rigid panels a try first. Two 365W panels shipped were less than $800 and the mounting hardware is probably going to come to less than $300.

[smac999]

There is no way a normal Bimini is going to hold 90 lbs. you would need to brace the heck out of it. Or Yiu need a whole custom struture. Normally an arch on the back. That is why flexible are used on Biminis. They are like 8lbs.

[flightlead404]

Originally Posted by Muaddib1116

I'm honestly a little surprised that sagging under it's own weight is an issue given the amount of snow they're designed to withstand on a residential roof. My concern was mostly for dynamic flex from wind and bouncing cracking the glass. What type of panels do you guys have? When were they made?

Its not the PANEL that is sagging, its the tube its mounted to.

I have Newpowa 210W panels

FWIW Mine is tied into my davits and my overhead 2" steel traveler arch. Just tying to a bimini frame I would not think sufficient. Mine is OVER the bimini but not tied to it.

Also, use triangulation as much as possible for strength and rigidity.

[Muaddib1116]

Originally Posted by flightlead404

Its not the PANEL that is sagging, its the tube its mounted to.

I have Newpowa 210W panels

FWIW Mine is tied into my davits and my overhead 2" steel traveler arch. Just tying to a bimini frame I would not think sufficient. Mine is OVER the bimini but not tied to it.

Also, use triangulation as much as possible for strength and rigidity.

Ok, so the panel itself was rigid enough. I will hopefully be able to set all this up next week sometime without the canvas, and I'll get a good idea of how the frame will take the weight and how my mounting system works. Thanks.