Another Solar Panel Upgrade
As mentioned in my article about replacing our Standing Rigging, I have to alter the Solar Panel install on Eximius.
Currently, we have 600W of Bougrv Solar Panels mounted on top of the Bimini laid out with the single panel athwartships in front of the Backstay bridle and two panels on either side of the backstay bridle.
Because the new standing rigging's Backstay bridle extends higher from the Bimini, I need to change the panel layout and that involves replacing the 3 existing panels.
The new layout will be as shown below.
The gap between the panels is due to the angle of the Backstay Bridle as can be seen in the lower image.
The panel dimensions are slightly larger than the area taken up by the old panels, I figured that out after completing the previous upgrade.
It looks like I'll be able to install a pair of approximately 435Watt panels giving a total of 870Watts of Solar Power. I know, that's not going to happen, but it should be much better than the Max 0f 600Watts we have presently. I would expect to get at least 700 watts. when the batteries need it.
The panels I'm looking at - next day delivery by Amazon, are about $540 for the pair.
From the specs of those panels, if connected in Parallel, the max output would be around 36v and 50amps. Well within the range of my Victron 100/50amp controller.
But if connected in series, the output would be more like 72v at 30amps and that's a better case for the MPPT controller.
For the wiring, I could keep the existing wiring from the panels to the controller, however, those wires are only 6awg and were only installed 3 years ago, they have suffered UV damage, so I'll replace them but with larger cables, 4 awg and I'll run those inside plastic conduit. Basically, I'll install a connector box beneath the solar panels with a terminal block inside, then wire inside of conduit down to the deck and into the side of the combing and to the area where all of the Victron equipment is located beneath the Nav Table.
Doing that should minimize the voltage drop between the panels and the controller.
Ok, that's the plan. Now I have to decide "Do I repair or replace the Bimini" before installing the new solar panels.
Now, I do have to comment on the whole issue of Solar Panel sizing and installation. From my experience over the past 11 years of boat ownership, I conclude that it's best to go big! I have purchased 2 Victron MPPT solar controllers a 100v/20amp and 100v/50amp. I should have purchased a 100v/70amp controller or two 100v/50amp controllers.
OK, back to the design of the Solar Panel mounting.
I like the idea of using 4040 Aluminum Extrusion, and wondered if Google Gemini could come up with a plan. Here's what I asked Gemini:-
( The text of the response is at the end of this post ) Here's the result: I made up this image using the suggested plan for the mounting frame. ( I use Google workspace drawing for most of my diagrams. )
Basically, using a Stainless Steel Hinged Bimini Rail Clamp on the Bimini Rail, use a couple of Nylon Ferrules as a stand off to allow the stainless bolt to pass through the Bimini Canvas and hold the whole thing together with a M8 T-Nut and bolt.
Gemini suggested I make a rectangular 4 sided frame using the 4040 Aluminum Extrusion, joining the Corners using Inside Corner Brackets.
This should result in a nice looking and substantially rigid frame on which to mount the two panels. I could put rubber washers between the Extrusion and the Hinge Clamp to add a bit of wiggle but I think I'll see how it comes out first.
Parts list
2 x 4 Pack of 4040 48 Inch Black Anodized Aluminum Extrusions
8 x Spartan Power Black Solar Panel Z Bracket Mount
8 Straight Line Connector Joint Brackets ( to join the 48" extrusions )
4 Stainless Hinged Clamps
4 M8 T-Nuts & Bolts
8 Nylon Ferrules ( 1/2" OD 1/4" ID)
I feel that this is coming together nicely. I'll go down to the boat on Monday and double check the dimensions of the panels and frame.
With that, I'll end this post, but here's a link to the Gemini response.
Stay tuned for the next phase.
Meanwhile, I hope to see you on the water.
Paul

















