New solar array with sliding panels

[s/v Jedi]

I started working on the next generation. Now that I can work with CAD design a bit and have the 3D printer for complex parts, this design with linear rails becomes a solid option.

Here is a rendering of the first of four solar panels. These are the big 450W bifacial panels from Renogy.

There’s the stainless steel arch we have on our stern. There are three 45” long 4080 aluminum extrusion beams attached to it with 3D printed clamps. Then the beams have slider cassettes attached to them that are assemblies from several 3D printed parts including slide inserts, end caps etc. each sliding panel has two 96” long 3060 extrusions attached that form the linear rails that go through the slider cassettes.

Work in progress…

[GordMay]

The panels slide out athwartships?

[Klausen]

Mads from "Sail Life" made a similar arrangement some years ago

[catmer]

Looks very neat,following

[Meaban]

Jedi, what was the issue with your previous sliding system?

[s/v Jedi]

Originally Posted by GordMay

The panels slide out athwartships?

I finished the key elements now, see attached pictures

First picture is the array retracted, second deployed.

[s/v Jedi]

Originally Posted by Klausen

Mads from "Sail Life" made a similar arrangement some years ago

Originally Posted by Meaban

Jedi, what was the issue with your previous sliding system?

Attached a picture of the current system, which was the first with sliding panels. Before that I had two versions with fixed panels, so I am now working on the 4th generation.

I started with the first in 2003 and the array on the arch was 220W. The current one is about 2,000W but in peaks, boosted by the bifacial factor, can do 10x as much as the first version

The current version is performing very well. The issues are:

- it uses sliders at the ends of the panels. The sliders will corrode, have ball bearings etc. and are also very heavy. They are way overkill for a 25kg panel but there are no lighter ones available.

- the sliders are mounted in a cassette which adds more weight and one end is all the way aft at the extreme overhang, together with two of the heavy slides.

- the current beams are carbon fiber over a douglass furr core and very long at 90”. The new beams are half at 45” and also much lighter 4080 aluminum extrusion beams. There is a thread with the build of the current system and probably the one before that too.

- the 2nd generation was very good as well. It used the same free panel overhang as this v4 but had 3 fixed panels. For close quarters maneuvering around high sea walls like in a lock or high mooring posts, it could easily crash into that while turning. The dinghy is underneath and with the sliding setup at two panels wide retracted, the dinghy is wider.

- v2 was destroyed by a hurricane that ripped a fitting apart. We went through two hurricanes last year with v3 but I tied the back end down, plus of course had it retracted.

[s/v Jedi]

I forgot about Mads. He was right where we are in Port Canaveral until he recently left for North Carolina. His system is pre 3D printing and I looked at it while building v3. It’s too flimsy and doesn’t slide very well, which is why I went for the setup of v3.

Now that we have 3D printers, we can make custom brackets and fittings that allow to do this right. Mads recently bought the same printer I have so I think we will see many similar projects from him as well, although with a catamaran there’s a lot more room for panels. I would still build a sliding system though because a cat is also much hotter inside and needs more A/C.

I have a second solar array above a hard top that is over our bridge deck. I plan to replace the whole hardtop with a much simpler construction that has this 4-panel sliding system as well, instead of the 2x 375W current setup.

[Dirk01]

Originally Posted by s/v Jedi

I forgot about Mads. He was right where we are in Port Canaveral until he recently left for North Carolina. His system is pre 3D printing and I looked at it while building v3. It’s too flimsy and doesn’t slide very well, which is why I went for the setup of v3.

Now that we have 3D printers, we can make custom brackets and fittings that allow to do this right. Mads recently bought the same printer I have so I think we will see many similar projects from him as well, although with a catamaran there’s a lot more room for panels. I would still build a sliding system though because a cat is also much hotter inside and needs more A/C.

I have a second solar array above a hard top that is over our bridge deck. I plan to replace the whole hardtop with a much simpler construction that has this 4-panel sliding system as well, instead of the 2x 375W current setup.

Hi Nick,

following. Have had the same idea but with your experience it makes no sense to invent the wheel again.

It's like your wiring setup. This will be my basis for my own setup (and most likely is only different in minor parts).
I plan to give it a thread after commissioning and 6 months of use. Maybe in one part or another I might find some finetuning (if ever)... ;-)

Cheers
Dirk

[Dirk01]

Originally Posted by Dirk01

Hi Nick,

following. Have had the same idea but with your experience it makes no sense to invent the wheel again.

It's like your wiring setup. This will be my basis for my own setup (and most likely is only different in minor parts).
I plan to give it a thread after commissioning and 6 months of use. Maybe in one part or another I might find some finetuning (if ever)... ;-)

Cheers
Dirk

Nick,

may I give you a thought/hint?
Thinking about the ship movement / twisting due to ship movement / load due to acceleration/deceleration, wouldn't it be a good idea to attach the solar panels to the frame with some sort of metal/rubber bearing? To allow the structure to yield or evade the forces? To distribute the forces across the structure? Or to decouple them somewhat from the basic structure (the arch itself)? Perhaps like motor mounts? Straight enough to take account of the mechanical overdetermination but rigid enough to ensure defined movements of the solar panels in the two positions (extended / retracted)?

Just my 2 cts...

Cheers
Dirk

Edit: I'll have a cat. Due to the two hulls and their distance to each other the movement / twist is surely more challenging.

[barnakiel]

Is this design 0 degree (flat laying) or can you tilt in any axis ?


Asking because I found tilting very effective.


barnakiel

[Dirk01]

Originally Posted by barnakiel

Is this design 0 degree (flat laying) or can you tilt in any axis ?


Asking because I found tilting very effective.


barnakiel

I'd suggest 2% (2cm/1m) should rinse the rain or cleaning water easily into the sea. Wind resistance should be negligible. But a tilting system would add a lot of construction / weight or less stability. As Nick already said - he lost some panels in a hurricane (despite retracted).

Probably the arch is a bit narrow / small which leads to a huge unsupported part.

Cheers
Dirk

[s/v Jedi]

Solar panels are sturdy but not strong enough for things like tilting. They are made to be fastened at four spots as in their instructions.

I often add reinforcement inside their frame, like an aluminum angle or flat extrusion, that I rivet in place.

For tilt you basically need to reinforce the entire panel, adding a lot of weight.

Luckily we don’t need to use tilt because we’re in the tropics.

[AndyOz]

The embedded picture files on here lose so much resolution I can't tell exactly how you've done it.

If you haven't already, you can get 316 stainless ball bearing sliders made in many sizes and weights. Typically used for tool drawers so can be very sturdy. Should suit, I imagine. You'd need the three-section ones so you can get full extension.

[s/v Jedi]

Originally Posted by AndyOz

The embedded picture files on here lose so much resolution I can't tell exactly how you've done it.

If you haven't already, you can get 316 stainless ball bearing sliders made in many sizes and weights. Typically used for tool drawers so can be very sturdy. Should suit, I imagine. You'd need the three-section ones so you can get full extension.

Sliders? That is our current array that I posted in #7 and that we don’t want anymore. The pictures have enough resolution when I zoom in enough, which I will do as I finalize components. These are all custom designed as I go, so I first try to get them to “production candidate” status before posting them