Raising the Solar Panels higher on the Davits

[bigmuffin]

Hi! I was wondering if you had any advice on how to raise my solar panels. The boat I bought came with davits and solar panels. I have attached two pictures which will hopefully give you an idea of the possible issue. There are two horizontal bars directly over the ends of the solar panel, causing shade on the panels the majority of the time.

I was thinking about raising the solar panels to be at the level of the horizontal bars, eliminating that shadow (even though the wind generator would still be an issue). However, I can't really find anything that I can use to move the panels higher. Is there any type of mounting kits I can buy that might be useful or do you think I would need something custom? Whatever it is I would need it to be pretty stable for rough conditions in the ocean. I searched online and really haven't found anything I think would work.

The other option is moving the panels out farther but I really don't want to add to the length of my boat...

Thanks!

 

[Rich Stidger]

I'm thinking that your worry about the shade is needless. If the picture shows the maximum shade that you have I think the affect of that shade on output is a very small amount and not worth the effort and expense to eliminate.

You could easily check the effect of the shade- put a large piece of paper on the solar panel and trace the shadow. Cut out the image of the shadow and then on a day where the sun is shining without a shadow, note the panel output and then drop your shadow pattern on the panel and see the change in output. If the pattern is opaque, the decrease in output that you measure will be more than the actual shadow will cause because even a shaded panel will put out something.

I'm betting that the shadow is causing less than 2-3 percent decrease. Ditto for the wind generator shadow.

If I am wrong, then at least you will know how much more you will gain if you raise the panel and you can determine if the effort is justified.

 

[Maine Sail]

Shading and solar don't go well together and with so few good hours of solar performance per day minimizing solar shading can go a long way to increasing performance..

 

[Rich Stidger]

Shading and solar don't go well together and with so few good hours of solar performance per day minimizing solar shading can go a long way to increasing performance..

I agree that shading decreases the performance. My point was that it appeared that the amount of shading due to the higher stainless frame was a small percentage of the panel. Your video shows 50% or more of the panel being shaded with a dramatic loss of output. Bigmuffin's shading is much less.

Anyway if it were me, I would want to know precisely how much I would gain by remounting the panels, knowing that the remounting may not be a trivial task.

 

[Joe]

Looks like it wouldn't be too much trouble to relocate the GPS antenna and re mount the panels onto the higher structure. You can purchase some aluminum "L" angle stock and U bolts to fabricate a mounting frame for the panels. Aluminum is very easy to work with. You don't need any specialty tools, just a hack saw to cut the lengths, flat file to smooth the edges and a power drill for the mounting holes.

 

[alexco38]

Turn the boat around ???

 

[bigmuffin]

I will do some comparisons in full sunlight and the putting a line of shade over the end of the panel. From reading various articles, I was under the impression that shade across a panel like that would have serious impacts.

If it doesn't then I will probably leave it alone. If it does, I will have to figure out how to build something strong to lift and support the weight of the panel on both ends.

 

[Maine Sail]

I will do some comparisons in full sunlight and the putting a line of shade over the end of the panel. From reading various articles, I was under the impression that shade across a panel like that would have serious impacts.

If it doesn't then I will probably leave it alone. If it does, I will have to figure out how to build something strong to lift and support the weight of the panel on both ends.

On mine it does. Remember the cells are in series so shade even one and performance drops off rapidly. My radar pole is my biggest problem but I have no way to move the panel higher than the radome. Most of the day it is a non issue but once it shades it can cut the output dramatically.

 

[All U Get]

Hi Bigmuffin,
From your picture it looks as if you could move the panels aft by redrilling the current mounts. Its hard to tell if you have enough wire to do it but that's a no cost option.
All U Get

 

[rrranch]

For what it's worth, our camper has two large solar panels on the roof a little bigger than yours. For two years now it's been parked under a couple huge oak trees where they are always mostly to fully shaded. I haven't plugged it in since we parked it there and we stay in it nearly every weekend. I just have a single optima battery in it and a 1500 watt invertor. About the only 110 appliance I run on solar power like that is a small box fan but we've never had problems. The inverter would shut off at 10 volts battery power and it never has. I think all the talk about shade is a little blown out of proportion. I'm about to put one of the same panels on the camper on our boat too.

 

[Maine Sail]

This is a better video and you can watch at about 3:00+ into it when he holds some pipes over the panel. It drops from about 9 amps to the low 7's the shading at 6:00 + is also good...

 

[Rich Stidger]

Well, Mainesail, your last video offering pretty much blows away my opinion... Truly, I would not have expected such a small percentage of shade from the pipes to cause the massive loss in output.

Thanks for the enlightenment!!

 

[Fly_H23]

Shade effects polycrystalline solar panels much more than amorphous types. While the poly type are more efficient for their size, amorphous work better in various light levels.

 

[cbsailor]

I'm not sure if this is the type of thing you are looking for, but here are some pics of my solar installation. The panels were raised to prevent shadowing by the bimini at low angles of the sun. The installation was done with standard bimini/railing fittings and 1" tubing. I cross drilled and bolted where required instead of relying only on the set screws. Is it ideal, maybe not. Did I need to worry about loosing output at those low sun angles, again maybe not, but it has been working great for me for about 2+ years now. The downsides are some marina's questioning the boat length, extra care when docking/undocking and Buddy, our cat. After two incidents where he skated across the wet panels into the drink, I think he's learned not to go there.

 

[arf145]

As you captioned in the video, "Wow." A good reason to make those expected daily outputs conservative.

 

[SNOWCROW]

Priceless...!

Turn the boat around ???

Too perfect :dance: And with the sun moving, and if the boat swings at anchor, the shaded amount looks to be less than 4% given the width of your panels and the shade of the frame.

 

[FourPoints]

My installation was for a much smaller panel, and without davits, but combined with cbsailor's design it may give you some good ideas.

http://sailingit.com/blog/boat-projects/solar-panel-mounting-and-installation

 

[bigmuffin]

Thanks for the suggestions. I have yet to test the panels due to other pressing matters (replacing the fuel tanks). The images of your installations do give me some ideas. I would just need to find the right hinges and SS tubing to lift them up. Exactly what I was trying to figure out. I see defender has most of what I need, but I might try to find some local that has smaller size SS tubing or that could give me tubing with the exact length. I’m sure I can find something in Annapolis..