Solar Arch - what material

[Stevens 47]

Originally Posted by chowdan

Have any more photos to share of the building and installation?

These are the only others I have.

[kryg]

I have just rebuild and extended my solar Tagra build from Aluimiuim 1" tube. To hold 2 x 360 watt solar panels for a total of =720 watts. Even though my boat is a mono hull. No matter mono or multi hull. In building your setup keep in mind is if you have too big an area in effect your building a hard sail no a good idea in strong winds. From my experience in 70 - 90 k winds could remove my setup if it was not so well constructed. See photos. Once installed no one seems to know where my solar panels are looking at the boat side on? Also, the advantage constructing Aluminium tubes, I'm able to remove the panels if need be. The naked tubes will have little wind effect of a hard sail in extreme winds trying to tear the structure down. I personally would not go any bigger than that on a tagra. for more power I would divide the panels into two groups by adding some solar panels onto the coach house. Finally, I would not paint Aluminium tubes, instead clear coat them with EverBrite a product used to protect my mast once I stripped off the old paint.

Good luck with your project if you get it installed correctly you will never need shore power.

Originally Posted by nfbr

I want to install a LARGE solar arch to hold ~2KW of solar on a catamaran

Approx 2m x 5M

I'm debating material choice

• Custom Fibreglass & Foam
• Fibreglass Pre-Fab Tube / Pipe ~4"
• Stainless Pipe (marine style - ~1-1.5")
• Stainless 316 Exhaust Pipe ~3-4"
• Aluminium Tube Painted

Most boats seem to go common stainless tube, and some go custom fibreglass arches.

Panels attachment not yet decided.

Opinions / ideas please?

Thanks
Paul

[DeValency]

Double SS 316, 2” arches mounted over the davits. Very strong, yet very light with all cables running inside the arches.

[daletournier]

I have an anodized aluminum Atlantic arch. All I can say is it's gone around the world , seen rough weather and never been a problem.

In shelterbay marina Panama while in a berth another vessel got out of shape and caught one of my davit arms with his back stay, once the mooring lines had pulled up tight the boat which is moving was trying to destroy the arch, one of the bolt on davit arms broke but no other damage to the arch. They are quite strong.

[billgewater]

This suggestion below, allows for (I hope) a potentially cheaper, lighter arrangement that allows panels to be removed/installed and cleaned easily. Plus it provides a rain proof resulting cover. It is intended for consideration with catamarans with many PV panels, not mono-hulls.
PV panels come with their own aluminium surrounding edge frame and it may pay to consider using that frame to assist with rain proofing the final panel arrangement.
Most arrangement have the panels attached on top of tubes or beams or attached to an existing roof structure. The suggestion below is quite different.

Consider; if each panel actually sits with its outside frame sitting in a channel surrounding trough. The trough, acting as a gutter, collects the rain water and drains it off the entire panel collection. When you look up from below you would see a matrix of the underside consisting of the channel/troughs plus the underside of each PV panel. Adjacent panel edges share the same trough, but the troughs are all joined so water can freely flow anywhere. (Depending on wind and the inclination of the array.)
You could also see from below, (and access) the wiring system for all the panels. The wiring is not exposed to direct sunlight or weather. The vertical faces of the alloy edges of the PV panels can’t be seen as they are in the trough channel area.
Each PV panel acts as a lid over a large rectangular hole that has vertical lips (trough edges). I would envisage the troughs to be about 2.5 inches wide and about 1.5 inches deep, but these dimensions would need to match the dimensions of the panel aluminium edges. Deeper channels are invariably stiffer than shallow ones so that may assist in design considerations.

To improve rigidity and offer support where needed, a tube with flanged ends could be bolted/attached to the underside of the trough and the deck below. You could use some soft rubber seating in the trough or over the top of the gutter edge to reduce stress loading on the panels and frame.
Just how each panel is fixed would depend on the use of some latching fittings – at least one on each end of the panel. Panels flying off in a stiff breeze could really ruin a day out. The latches should be fully accessible from under the panels.
An important feature of the latches is that they should not allow rain water ingress and ideally (if possible) allow the panels to be slightly tilted if you seek to optimise sunlight energy.
How wide should the troughs be? The minimal width would be enough to accommodate two panel edges, but it could be even wide enough to allow foot width where you may want to move around the top of the panels (unlikely).
If the troughs are made of extruded alloy, welding can be minimised by using off the shelf corner pieces and riveting. (Welds invariably crack in these lattice like structures that undergo some flexing). The troughs could also be UV safe extruded plastic. Cheaper than metals. Easier to work with.

To install or remove panels all you need to be certain of is that the internal diagonal of each large space exceeds the longest dimension of the panel to be lifted up through the space. That should not even be an issue unless there are diagonal braces on all four corners. Ease of panel removal means that you can remove one panel, stand on box and stick your head outside above all the panels to clean the surrounding panels. Gather the bird poo.

If the geometry of the PV edges is a bit complicated there are options. A typical option may be to rivet a sealed extrusion (step shaped) onto the outside of the vertical face of the PV edge that creates its own slot that can go over the vertical lip of the trough. This means that the PV panel is actually inside the hole you would see from below. There are other options.
With a bit of clever plumbing, the troughs can direct the rain water to a collection site and be used for cleaning, flushing, showering etc., rather than just going overboard.
I have not seen this approach used but when I see panels attached to expensive pre-existing roofing structures it seems that there should be better alternatives. This suggested model means that you do not need to construct a glass/foam roofing at all. It is an integrated system.
It may be more appropriate for a large array as is common on catamarans, with their large aft deck areas and need for power. Sheeting, mainsail shading and rigging issues are certainly present on catamarans and would need to be considered.
The final result above may look a little “agricultural” but them’s the breaks. Some of the SS support systems I have seen have been seriously expensive but still ugly. The appearance of any PV array is constrained by the flat panel shapes and large flat surfaces are a bit unusual on any boat. The above suggestion may still be expensive, but if you use off the shelf extrusions for the troughs, it could be very much cheaper.

However, it may be worth considering – in part or totally. E.g. if you build a strong support system for the davits, that structure could be incorporated into the suggestion above by providing some of the required support for the PV panel troughs.
A possible downside is that the “holes” created by the trough matrix matches the PV panel edges. So if you decided at a later date to replace the panels with different sized ones, you may be left an unhappy chappy.
To date, there appears to be few, if any, new boats that come with an integrated PV system. It’s all add-ons. (Which is a bit sad considering the move to PV panels and lithium batteries.)
And they look like add-ons as well. Maybe the suggested scheme provides a shift in thinking.
I can’t provide any sample photos but maybe someone else has seen a similar “attempt”. If so, please let us all know.
On a nearby large motor vessel the owner is building a complete roof using PV panels (over a dozen panels from what I can see). To prevent water ingress he has built a substantial frame system, attached the PV panels and then sealed it all with silicon. That’s another option. Simpler, but I am sure you can see an issue.

[David B]

Originally Posted by nfbr

I want to install a LARGE solar arch to hold ~2KW of solar on a catamaran

Approx 2m x 5M

I'm debating material choice

• Custom Fibreglass & Foam
• Fibreglass Pre-Fab Tube / Pipe ~4"
• Stainless Pipe (marine style - ~1-1.5")
• Stainless 316 Exhaust Pipe ~3-4"
• Aluminium Tube Painted

Most boats seem to go common stainless tube, and some go custom fibreglass arches.

Panels attachment not yet decided.

Opinions / ideas please?

Thanks
Paul

50/60mm stainless steel tubing, integrated into the pushpit, like it was factory-fitted, rather than a 'bolt-on'

[chowdan]

Were you able to run your PV and all wiring through the arch in your tower? I have atlantic tower and a fan of it. All my wiring is external as a neighbor said there is a blockage in the tubing somewhere preventing you from running a wire

Originally Posted by daletournier

I have an anodized aluminum Atlantic arch. All I can say is it's gone around the world , seen rough weather and never been a problem.

In shelterbay marina Panama while in a berth another vessel got out of shape and caught one of my davit arms with his back stay, once the mooring lines had pulled up tight the boat which is moving was trying to destroy the arch, one of the bolt on davit arms broke but no other damage to the arch. They are quite strong.

[Juice13]

Originally Posted by jas

Here's our new arch with swim platform and ladder up. S/S316L in various diameters. Arch was of 2" and some of platform 2 1/2" with 1" for ladder.

That looks well made. I see New Bern on your stern, was this done locally? We are in Oriental looking for some SS design and build out of a new stern rail / swim ladder / catbird seats / solar arch / davit system for a Tartan 34c.

Thanks

[daletournier]

Originally Posted by chowdan

Were you able to run your PV and all wiring through the arch in your tower? I have atlantic tower and a fan of it. All my wiring is external as a neighbor said there is a blockage in the tubing somewhere preventing you from running a wire

Hi, yes I ran it internally. There is a blockage in the rear tubes, of course I didn't find this out until I drilled the holes and attempted to run the wires. Theres no blockage in the forward tubes. They should mention this.

[chowdan]

This is great to know. What side did you run down?

Originally Posted by daletournier

Hi, yes I ran it internally. There is a blockage in the rear tubes, of course I didn't find this out until I drilled the holes and attempted to run the wires. Theres no blockage in the forward tubes. They should mention this.

[daletournier]

Originally Posted by chowdan

This is great to know. What side did you run down?

The starboard side.

[Palarran]

Many of the comments seem to not recognize that you are asking about a catamaran arch. First off, what cat do you have? Second, 2000 watts of solar is a lot of square feet of space. Do you actually need that much? Let me guess, you want to run an air conditioner off it, right.

Are you willing to potentially give up good sailing to have that much? Will the installation prevent you from accessing your boom easily? Will running rigging have any chance of snagging the structure? Could it create a danger?

I have a 56' cat that is 26' wide and put 1300 watts of solar on it. I'm sure that more could have been added but one of the above questions would have become YES. I have seen many installs that really look stupid to put it bluntly. Like a massive platform of panels hanging off the back of the boat. Ugly to the utmost and IMO very suspect when in 50 knots of wind.

I guess it's hard to imagine why you would need that much solar. I run a large cat completely except the water maker and air conditioners off my 1350 watts. For those two items we have a generator. That generator could be as small as a 5kw and fully power the boat and one of those two.

As for my install, there are three 315 watt panels on the hard top bimini which is built out of fiberglass but supported by aluminum. Then there are two 190 watt panels on my arch, which is also aluminum tube. The arch was originally for sat com's but technology made that system obsolete. Unfortunately I don't have photos of the system installed but do of the arch and bimini.

[vpbarkley]

Aluminum tubing is fine for this, ours is 2" diameter and functions additionally as davits.
Make sure the mounting feet are spaced far apart, front to back, to reduce deck loading.

[sv Stella Maris]

I built the same system outfitted on Scott and Laurie’s boat, YouTube ‘Off the Starboard Hull’

They used the plans from Rolf’s Lagoon 450, and I built the same.

In fact my desal is running now off the solar and 800ah 12v AGM system. 130 liters per hour....boom.

I would use the Q-Cell 420w panels from Hanwana (spelling?) via AltE Energy...ask for Blanca.

4 or 5 will take care of your needs...

Check out ‘Lagoon 450 Modification’ thread on this forum for specific solar array details.

[Xlantic]

Originally Posted by billgewater

This suggestion below, allows for (I hope) a potentially cheaper, lighter arrangement that allows panels to be removed/installed and cleaned easily. Plus it provides a rain proof resulting cover. It is intended for consideration with catamarans with many PV panels, not mono-hulls.
PV panels come with their own aluminium surrounding edge frame and it may pay to consider using that frame to assist with rain proofing the final panel arrangement.
Most arrangement have the panels attached on top of tubes or beams or attached to an existing roof structure. The suggestion below is quite different.

Consider; if each panel actually sits with its outside frame sitting in a channel surrounding trough. The trough, acting as a gutter, collects the rain water and drains it off the entire panel collection. When you look up from below you would see a matrix of the underside consisting of the channel/troughs plus the underside of each PV panel. Adjacent panel edges share the same trough, but the troughs are all joined so water can freely flow anywhere. (Depending on wind and the inclination of the array.)
You could also see from below, (and access) the wiring system for all the panels. The wiring is not exposed to direct sunlight or weather. The vertical faces of the alloy edges of the PV panels can’t be seen as they are in the trough channel area.
Each PV panel acts as a lid over a large rectangular hole that has vertical lips (trough edges). I would envisage the troughs to be about 2.5 inches wide and about 1.5 inches deep, but these dimensions would need to match the dimensions of the panel aluminium edges. Deeper channels are invariably stiffer than shallow ones so that may assist in design considerations.

To improve rigidity and offer support where needed, a tube with flanged ends could be bolted/attached to the underside of the trough and the deck below. You could use some soft rubber seating in the trough or over the top of the gutter edge to reduce stress loading on the panels and frame.
Just how each panel is fixed would depend on the use of some latching fittings – at least one on each end of the panel. Panels flying off in a stiff breeze could really ruin a day out. The latches should be fully accessible from under the panels.
An important feature of the latches is that they should not allow rain water ingress and ideally (if possible) allow the panels to be slightly tilted if you seek to optimise sunlight energy.
How wide should the troughs be? The minimal width would be enough to accommodate two panel edges, but it could be even wide enough to allow foot width where you may want to move around the top of the panels (unlikely).
If the troughs are made of extruded alloy, welding can be minimised by using off the shelf corner pieces and riveting. (Welds invariably crack in these lattice like structures that undergo some flexing). The troughs could also be UV safe extruded plastic. Cheaper than metals. Easier to work with.

To install or remove panels all you need to be certain of is that the internal diagonal of each large space exceeds the longest dimension of the panel to be lifted up through the space. That should not even be an issue unless there are diagonal braces on all four corners. Ease of panel removal means that you can remove one panel, stand on box and stick your head outside above all the panels to clean the surrounding panels. Gather the bird poo.

If the geometry of the PV edges is a bit complicated there are options. A typical option may be to rivet a sealed extrusion (step shaped) onto the outside of the vertical face of the PV edge that creates its own slot that can go over the vertical lip of the trough. This means that the PV panel is actually inside the hole you would see from below. There are other options.
With a bit of clever plumbing, the troughs can direct the rain water to a collection site and be used for cleaning, flushing, showering etc., rather than just going overboard.
I have not seen this approach used but when I see panels attached to expensive pre-existing roofing structures it seems that there should be better alternatives. This suggested model means that you do not need to construct a glass/foam roofing at all. It is an integrated system.
It may be more appropriate for a large array as is common on catamarans, with their large aft deck areas and need for power. Sheeting, mainsail shading and rigging issues are certainly present on catamarans and would need to be considered.
The final result above may look a little “agricultural” but them’s the breaks. Some of the SS support systems I have seen have been seriously expensive but still ugly. The appearance of any PV array is constrained by the flat panel shapes and large flat surfaces are a bit unusual on any boat. The above suggestion may still be expensive, but if you use off the shelf extrusions for the troughs, it could be very much cheaper.

However, it may be worth considering – in part or totally. E.g. if you build a strong support system for the davits, that structure could be incorporated into the suggestion above by providing some of the required support for the PV panel troughs.
A possible downside is that the “holes” created by the trough matrix matches the PV panel edges. So if you decided at a later date to replace the panels with different sized ones, you may be left an unhappy chappy.
To date, there appears to be few, if any, new boats that come with an integrated PV system. It’s all add-ons. (Which is a bit sad considering the move to PV panels and lithium batteries.)
And they look like add-ons as well. Maybe the suggested scheme provides a shift in thinking.
I can’t provide any sample photos but maybe someone else has seen a similar “attempt”. If so, please let us all know.
On a nearby large motor vessel the owner is building a complete roof using PV panels (over a dozen panels from what I can see). To prevent water ingress he has built a substantial frame system, attached the PV panels and then sealed it all with silicon. That’s another option. Simpler, but I am sure you can see an issue.

Bilgewater, interesting thoughts. Not sure I understood everything (diagrams would help!).

I recently built a 3 metre by 4 metre structure to accommodate 6 1x2m 330 W panels. I used rectangular aluminium tubing which, after construction, I etch-primed and painted with 2-part PU paint.

The panels nest within 1x2 m "holes" in the aluminium tube structure, resting on welded tabs to which they are bolted. I have not done it yet but i plan to use Sika 295 (UV proof) in the gaps of the panels, from above, to make them rain-proof.

To avoid the flatness that you rightly say is more appropriate for an agricultural structure than a boat I angled the side panels a few degrees down from the centre-line ones which are flat.

Having 2 kW of solar means no need to run the genny

(Sorry about the picture but it is the only one I have readily available)