Solar Bimini

KaJen's bimini was wearing out and the quotes to replace it were silly expensive (it's a boat so what else would I expect). So I decided to replace it with solar panels.



The system: Six Kyocera 265 watt panels totaling 1,590 watts. This was split into two arrays (three forward and three aft) that feed into two Midnite Solar Classic 150's. The house battery bank consists of eight Odyssey 2150 AGM's for 800 AH total.





The system has been live for 10 days and I am more than pleased with the results so far. KaJen is not a particularly power hungry boat so I have left the TV on for three or four hours for a couple of days, and have not been careful about lights, microwave, etc. I am averaging around 265 AMPs per day usage. I have had seven days running for three to four hours (short hops in the Keys of 20 to 30 miles) then anchoring for the night, and three days at the dock with no shore power, no generator and no engine. Even at the dock, by 1 o'clock the chargers are in float, sometimes with one of the chargers in rest mode. Even today, cloud cover and drizzle all day, by 5 o'clock the system has produced just over 2,000 watts.



The framework is all 1 inch heavy duty stainless, with set screw fittings. So far it has been through 35 mph + winds and seas rough enough that I came in for shelter (3 to 4+ on the beam at 5 seconds made KaJen a rock and roller). The frame and panels have been rock solid.
Arch

Great post, and thanks for the photos. Guess I had never thought in terms of the panels actually being the Bimini top -- that is pretty creative. Could you be more specific on how you fastened the panels to the stainless steel tubing???

Thanks John,
I ran aluminum T bar for and aft and thru bolted the panels to those.


Then I used cushioned stainless clamps from Grainger to bolt the panels to the tubing. I used the rubber cushions to avoid rattling. It will be interesting to see if they get enough sun to rot out.



Hope this helps,
Arch

It helps. It does indeed. Gives me some very definite ideas. Thanks.

Great job Arch. Always thought skipping the canvas in favor of panels made infinitely more sense.

CPseudonym said:

Craig - AKA Some Clueless Idiot

Click to expand...

Not clueless, and not an idiot. But definitely one who very much prefers to march to his own drummer. I raise a toast to you, Craig. One of my heroes, and that is an honor not lightly bestowed.

Arch, this is a great idea. My concern, and I know it has not been a problem for you despite some testing weather, is the risk of flexion affecting the panels. Provided that is not an issue I see a market opening, perhaps even an economic advantage over having a custom made f/g bimini hardtop for boats not built with one.
It may be, unlike your solid frame,many standard canvas cover bimini frames lack the rigidity to accommodate panels without risk of flexion damage and would need replacing or reinforcing.

That's a great idea. Did you seal between the panels for water?
One small pc of advice is keep an eye on the set screws. I had a T top on a small boat that was held together with them. Had to re tighten them semi regularly.

Bruce,
Thanks. Flexion was one of my primary concerns. The "old" frame was made of lighter weight stainless and was simply not adequately braced to handle the weight of the solar panels.

The panels themselves are surprisingly strong and ridged and when tied together provide additional strength to the system. I am not an engineer (ex CPA) so I have run no numbers but the system as a whole does not appear to sway, twist or deflect at all. Time will tell.

As to economics, the trade off between having a new bimini sewn up and the solar system was surprisingly small. I haven't added up all the costs but when you consider 6 panels at $250 = $1,500 and 2 top of the line controllers at $565 = $1,130, that's only $2,630 for the major components. Steel, wiring, breakers even at a couple grand is still in the ballpark for a new Bimini. Note that I supplied all labor.

I intend to use the old Bimini frame to add additional shade and soften up the perimeter of the panels.

Arch

Mbevins, I did seal between the panels on the fore and aft seams and they appear to be fine. The sideways seams still need to be sealed up, should not be too difficult. Full disclosure, I sealed everything, then had to take the panels down for hurricane Mathew. Ran out of time before taking off for Key West. I have no idea where I found the time to work before I retired. ��

I agree on going around and checking set screws. One more maintenance item!
Arch

Arch,
That is a beautiful job. You could use Loc-tite on the setscrews.

Do you have any detail photos of the clamps and t-bar installed to the tubes?

I am going to put solar on my boat (37ft Puget Trawler) this year. Your boat looks to be a Tiawan cousin to mine.

Larry,
Thanks! I will try to get better pics tomorrow but for now:

This shows the T-bar. Note that it is a fairly substantial piece of aluminum. There are two of them running the full length of the panels.



Here you can see one oh the bolts that goes thru the panel frame, thru the T-bar, and thru the panel frame on the other side. You can also see the clamp around the cross bar that bolts thru the panel frame.



And finally a clamp on the outside edge of the panel frame



Hope this helps,
Arch

Greetings,
Re: post #7 (Loctite on set screws). I don't think the necessity for re-tightening the screws is as a result of them loosening. The most probable mechanism is the tip of the screw deforms the tubing when the whole structure flexes/moves causing looseness thereby making a regular re-tightening necessary. So, Loctite will keep an already loose screw from backing off and disappearing but will do nothing to prevent the deformation of the tubing. Re-application of the Loctite would be necessary with every course of tightening.

Quite a nice job. Win/win.

Arch,
That's great detail. Any further detail photos would be greatly appreciated.

Is the t-bar about 1 inch by 1 inch by 1/4in thick?

Where did you install the controllers?

Firefly,
Good point. Do you think the set screws would eventually cut in as much as they will, and become stable?

Larry:
Aluminum 6061-T6 Bare

T-Bar

1.5" x 1.5" x 0.25"

Cut to: 131"

RTF,
I agree. I started off using blue locktite and realized that I still needed to tighten the set screws a few times as they settled in. It seems that most of them are staying tight at this point so I will begin locktite applications as I go along.

Arch

Greetings,
Mr. LH. "... as much as they will, and become stable?" I don't think it's a matter of "cutting in" as it is tube deformation. I suppose the tube can only deform so much until it is fully restrained by the fitting. So, yes, the joint, should become stable at some point.

I think Mr. A is using a sensible approach and I suspect it will reach a point where an application of Loctite will be of use.

Arch, Firefly,

Thanks for your replys.

I had figured out most of my solar installation plans, but these details help a lot.

Arch,

Do you have a photo showing how you mounted the lower ends of the arches?

Very cool, Arch. I take it in the openness of the Keys, you rarely encounter height clearance issues. See any problem building that whole frame as a collapsible design?

Great set-up, and huge output for a boat. Many a house here in Queensland has only that sort of output from roof solar, although we have 6kW, because we had the room.

I have a quite puny solar set-up on my boat, as we don't run any AC away from the berth, but what I have are two Uni-solar flexible panels, mounted down on some spare deck up top where we don't need to walk. I got flexble because initially I have them mounted over the cockpit canvas cover, but chafing soon revealed that to be a bad idea.

However, just out of interest, I wonder how much wattage, and at what price, some of these new zipped-into-the-bimini-fabric systems might go for a similar sized bimini area..?
Being integral to the bimini itself, and flexible, chafing and flexing would not be a problem, but at the same time, although you would not get the output the OP is getting, the weight and windage would be less, and water-proofing automatic. Just a thought. Has anyone gone down this path..?

http://www.ecoboats.com.au/productrange_solbianflex.php

http://www.pristinemarine.com.au/flexible-marine-solar-panel.html

http://www.ecoboats.com.au/productrange_solbianflex.php

Great setup Arch. I had toyed with a similar idea except I was going to build the frame over the aft cabin. We ended up selling the boat before we got that far.

Have you given any thought on how you will clean the panels from salt and bird poo buildup?

Re: Re-tightening. Perhaps 2 metal+1 rubber (in between) washers/bushings would do the trick?

Really cool sollution You found there - much like a "Alexanders cut"!

That is a great set up, and I might try to do the same on my boat. When I built the frame work for solar on my sailboat I used JB Weld where some of the fittings came together, creating a pretty solid joint that did not have to be retightened. Just a thought. Great work, and thank you for posting it for the rest of us.

Cheers, Bill

I like the setup, Arch! I've considered something similar for my FB and envisioned a hardtop with cutouts for the solar panels to provide a more traditional appearance. It would need a stout stainless structure to support the increased weight and windage. If and when my canvas dies, I'll look into that option.

Nice job!!

Larry,
The controllers are mounted behind the ladder (stairs) leading down to the forward cabin. Unused space in my boat and batteries are right on the other side of the bulkhead.

Pics of lower mounts:




Arch

FlyWright,
Rather than make a hardtop with cutouts, consider fabricating a "rim" around the outside similar to a rain gutter except made to look like the edges of a traditional hard top. The pieces could easily be screwed to the outside edges of the panels.

I am planning to do something like that but I will use canvas to make it look something like a canvas T-top. I will likely make canvas covers that will snap onto the underside of the panels.

Then of course there are the lights, etc. it never ends ��

Arch

Arch,

Many thanks for the details. You have done a great job.

Quick update December 18, Key West.
Complete overcast and rain today.
System is producing just over 300 watts, 25 AMPs at 13.5 volts.
I have not plugged into shore power, run the engine, or generator in 18 days. I have been aboard full time, watching tv, running tools, and using the boat as I normally would. During that time batteries have been fully charged each day and have never been below 60% when I check in the morning.
Arch

I've got years of planning still ahead, but a solar bimini is definitely on the list. Very nice, Arch.

Just went through this thread, very nice work and very useful info!
This gives me nice ideas as wanted to do the same on my boat.
Thank you very much!

Lou