Rail mounting solar panels

[stranded]

A simple question I think for anyone with a mechanical mind. I've got two 100W (so very roughly 1200 x 590mm, 8kg) rigid solar panels to mount on the pushpit side rails. The connection will be through a pair of NOA rail mounts - the sort (B I think they are designated) which allow the panel to slide. I had planned to use canopy fittings to fix a strut between the lower pushpin rail and outer panel edge to prevent the NOA rail fittings turning in testing conditions. Still possible, though the rail mounts for canopy fittings all seem to have the cotter pin arranged so the strut pivots in line, whereas I would need it perpendicular) But. Is there a significant mechanical disadvantage (or indeed advantage) to using tensioned lines from the outside edges of the panel to the lower pushpit rail so as to prevent movement by 'pulling the edges in' with rope rather than pushing one edge out with a rigid strut? Does this make any sense?

 

[Lon nan Gruagach]

These:

Work very well. A larger, similar, fitting that fits scaffold pole sized rails needs no other fixing on 1m² panels that have been out in 100mph gusts. The wind loading is almost perfectly balanced so they stay put.
If you are concerned that your rails are too small for this to work then you might sleeve them and fix the sleeves with a pin.

 

[stranded]

These:

Work very well. A larger, similar, fitting that fits scaffold pole sized rails needs no other fixing on 1m² panels that have been out in 100mph gusts. The wind loading is almost perfectly balanced so they stay put.
If you are concerned that your rails are too small for this to work then you might sleeve them and fix the sleeves with a pin.

Yes - exactly those. I have them to fit my rails but was concerned that they would not be secure enough to resist the twisting force of big weather. But at 100mph the solar panels will be the last thing on my mind!

 

[Heckler]

A simple question I think for anyone with a mechanical mind. I've got two 100W (so very roughly 1200 x 590mm, 8kg) rigid solar panels to mount on the pushpit side rails. The connection will be through a pair of NOA rail mounts - the sort (B I think they are designated) which allow the panel to slide. I had planned to use canopy fittings to fix a strut between the lower pushpin rail and outer panel edge to prevent the NOA rail fittings turning in testing conditions. Still possible, though the rail mounts for canopy fittings all seem to have the cotter pin arranged so the strut pivots in line, whereas I would need it perpendicular) But. Is there a significant mechanical disadvantage (or indeed advantage) to using tensioned lines from the outside edges of the panel to the lower pushpit rail so as to prevent movement by 'pulling the edges in' with rope rather than pushing one edge out with a rigid strut? Does this make any sense?

I took off the wire gates on my Bene and put in 1" tube attached to clamps. Then I used plastic clamps on each corner to attach them to the tube, they now swivel with a single piece of notched hardwood to adjust the angle of dangle with a piece of 12mm shock cord to keep them tensioned. Works great in all weather thrown at me so far. My buddy, Geem, did it first and has crossed the Atlantic with them. I am sure he will be along soon!
Stu
PS, I got the bits off Jon here http://www.nauticayamar.com/contact-us.html significantly cheaper than herein the UK

 

[Heckler]

A simple question I think for anyone with a mechanical mind. I've got two 100W (so very roughly 1200 x 590mm, 8kg) rigid solar panels to mount on the pushpit side rails. The connection will be through a pair of NOA rail mounts - the sort (B I think they are designated) which allow the panel to slide. I had planned to use canopy fittings to fix a strut between the lower pushpin rail and outer panel edge to prevent the NOA rail fittings turning in testing conditions. Still possible, though the rail mounts for canopy fittings all seem to have the cotter pin arranged so the strut pivots in line, whereas I would need it perpendicular) But. Is there a significant mechanical disadvantage (or indeed advantage) to using tensioned lines from the outside edges of the panel to the lower pushpit rail so as to prevent movement by 'pulling the edges in' with rope rather than pushing one edge out with a rigid strut? Does this make any sense?

View attachment 61003I dont know why it comes out upside down! But it gives you an idea of what I have done!
Hinges on the top angle of the panel, notched pusher stick on the bottom, the notches rest on the toe rail with 12mm shock cord with a hook on tied parallel to the pusher and hooked on the toe rail as well.

 

[d4raffy]

I use the stanchion as a support for an extending bar brace.
I have used these fittings for 2 years now ... but am moving to the same NOA fittings as you for next season...
.. so i can move the panels more outboard when required.
I also use smaller serial panels to keep the voltage high and parallel either side to combat shading.

https://farm6.staticflickr.com/5713/25352710699_c99de7d8fb_z.jpg
https://farm6.staticflickr.com/5664/22810522198_e4eb8b4cce_c.jpg
https://farm6.staticflickr.com/5555/22810094158_36a94ba330_c.jpg

 

[stranded]

Thanks guys - yes, that is the sort of thing I am trying to do. I just want enough articulation so that with the sliding NOA fittings (which I have already bought) I can achive some degree of variation on the angle to the sun by sliding them inboard/outboard. Though from Dougal's contribution I might see how they do on their own - that's why I wanted to bring a mechanical mind to bear because it hadn't occurred to me that with the panel centred over the rail the wind forces would in themselves largely cancel out on each side of the panel (might have to streamline the under edge to stop the frame profile 'catching' significantly more wind underneath - though if that is a real rather than imagined imbalance, maybe could achieve similar effect by setting up off centre. Could then go for a simpler strut to support when the panels are fully outboard when anchored/moored and max sunbathing space required!

 

[Heckler]

Thanks guys - yes, that is the sort of thing I am trying to do. I just want enough articulation so that with the sliding NOA fittings (which I have already bought) I can achive some degree of variation on the angle to the sun by sliding them inboard/outboard. Though from Dougal's contribution I might see how they do on their own - that's why I wanted to bring a mechanical mind to bear because it hadn't occurred to me that with the panel centred over the rail the wind forces would in themselves largely cancel out on each side of the panel (might have to streamline the under edge to stop the frame profile 'catching' significantly more wind underneath - though if that is a real rather than imagined imbalance, maybe could achieve similar effect by setting up off centre. Could then go for a simpler strut to support when the panels are fully outboard when anchored/moored and max sunbathing space required!

My swivels are bolted to the top angle, if I had done it half way, when it was deployed, half would have blocked the narrow bit between the rail and the spray hood.
Stu

 

[PaulRainbow]

I have a similar sized panel at the stern, attached to a pole. The pole can rotate and the panel can tilt, so it can always be directly facing the Sun, although i rarely bother to move it.

 

[PuffTheMagicDragon]

View attachment 61003I dont know why it comes out upside down!

Is this better?

 

[Heckler]

Is this better?

Mwah! Ipads are supposed to be wonderful BUT !
Stu
PS up the Guadiana, Alcotim pontoon, the week before in Ayamonte we had watched Wales bladder Belgium good style! This is where Portugal did us! We watched it in the bar!

 

[vyv_cox]

In the past twelve years in the Med I have managed to destroy three stanchions in almost exactly the position that the solar panel in the photo is mounted. One of these was my fault, berthing stern-to in a force 7 in Sardinia, but the other two were done by others, one when I was not on board. In each case the panel would have been wrecked. Yet another good reason why people mount them on arches.

 

[neil1967]

Vyv

I too am looking at mounting panels on the rail as in Puff's photo, but using the brackets shown in post #3 it should be possible to store the panels on the inside of the stanchions, rather than the outside, with the (presumably) more fragile side of the panel facing inwards. To deploy the panel for use, you would only need to lift the panel (using the sliding mechanism of the brackets) and then rotate the panels outwards over the rail and then secure them horizontally. Given the damage you have previously endured, do you think that panels mounted this way would be less likely to be damaged than panels secured as in the photo?

 

[stranded]

In the past twelve years in the Med I have managed to destroy three stanchions in almost exactly the position that the solar panel in the photo is mounted. One of these was my fault, berthing stern-to in a force 7 in Sardinia, but the other two were done by others, one when I was not on board. In each case the panel would have been wrecked. Yet another good reason why people mount them on arches.

In the scheme of things, for us say £450 in replacement panels over 12 years seems a fair price to avoid the aesthetic compromises of an arch.

 

[vyv_cox]

Vyv

I too am looking at mounting panels on the rail as in Puff's photo, but using the brackets shown in post #3 it should be possible to store the panels on the inside of the stanchions, rather than the outside, with the (presumably) more fragile side of the panel facing inwards. To deploy the panel for use, you would only need to lift the panel (using the sliding mechanism of the brackets) and then rotate the panels outwards over the rail and then secure them horizontally. Given the damage you have previously endured, do you think that panels mounted this way would be less likely to be damaged than panels secured as in the photo?

Yes, I would think that stowing panels on the inside would give a lot more protection, at least from all of my incidents that were all caused by interlocking of stanchions on adjacent boats. I'm not quite sure what would happen with Stu's method, where a horizontal tube is connected to the stanchions. Stowing them like that on my boat is not an option, the walkway is already too narrow, but for a whole variety of reasons I would much prefer an arch.

 

[vyv_cox]

In the scheme of things, for us say £450 in replacement panels over 12 years seems a fair price to avoid the aesthetic compromises of an arch.

The aesthetics are a matter of opinion, I suppose. Obtaining a replacement panel of exactly the same size and specification when cruising the Mediterranean may be no easy task. This season we needed a new stripper arm for our windlass. The Greek agent had one in stock, its cost was €10. It was shipped to the nearest point at which we could collect it. €18. We hired a car for the day to go for it after being assured that the package would be ready for collection. €60 (it was in August). It was not there. Next day we went by taxi for it. €30. At least the stripper arm was the right one!

 

[dunedin]

I dont know why it comes out upside down! But it gives you an idea of what I have done!
Hinges on the top angle of the panel, notched pusher stick on the bottom, the notches rest on the toe rail with 12mm shock cord with a hook on tied parallel to the pusher and hooked on the toe rail as well.

It looks like you replaced the top stanchion wire with a s/s tube to provide the base for the panel brackets.
How did you attach the s/s tubes - did you weld (preventing removal) or use some kind of bracket?

 

[PuffTheMagicDragon]

How did you attach the s/s tubes - did you weld (preventing removal) or use some kind of bracket?

I think that Stu used Bimini fittings:

 

[stranded]

The aesthetics are a matter of opinion, I suppose. Obtaining a replacement panel of exactly the same size and specification when cruising the Mediterranean may be no easy task. This season we needed a new stripper arm for our windlass. The Greek agent had one in stock, its cost was €10. It was shipped to the nearest point at which we could collect it. €18. We hired a car for the day to go for it after being assured that the package would be ready for collection. €60 (it was in August). It was not there. Next day we went by taxi for it. €30. At least the stripper arm was the right one!

I can see that being an issue with a replacement part, but while a solar panel on NOA brackets might require a couple more holes screwed in the alloy extrusion but otherwise they are pretty adjustable to whatever is around. And as Neil says, the beauty of the sliding brackets is that we can both stow and deploy them inside the guardrails when they might be threatened eg in marinas but outboard and out of the way when at sea in fair conditions or at anchor etc.

 

[Martin_J]

Nooka

I used the NOA rail mounts for a couple of 50 watt solar panels on the pushpit.

Photo here...
Jubilant at Portland Marina

The mounts feel very secure and although I did buy a couple of rods and dinghy tiller UJs to make some adjusters, I ended up propping them up with a few left over plastic pipes and they've survived a year like that.

One thing to note about the NOA mounts is that they are designed for 25mm rails and you might find you have 1" rails. They really don't clamp easily around the 25.4mm rail but if you clamp them perhaps on a warm day, then tighten up gradually over a few days, they will fit in the end.

I believe NOA have suggested sanding the insides down a bit - but don't worry, they do fit eventually.