Solar panels on rigid bimini? Shading

[roland stockham]

Hi All
I have the opportunity to get a flexible 250w panel which would mount perfectly on a rigid bimini over the cockpit. Would give excellent shade and weather protection to the cockpit so could be an ideal solution.

What worries me is the boom shading as inevitably to boom will be above it. The panel has 3 narrow 85w banks of cells which would run fore & aft so I am thinking worst case I loose 1/3 of the output if one bank is shaded.

Anyone tried a similar arrangement , how does it work in practice?

Note - The underlying problem (apart from the usual lack of space on a small mono-hull) is getting panels to the boat in Aruba, delivery is next to impossible as glass panels are two big and heavy. These are lightweight flexible panels so can go by air.

[ullar]

Hi Roland,

I'm quite sure that's feasible. Keep those 85W banks connected parallel and you only loose the output of shaded banks. I agree very much with you about lack of space for solar panels on monohull boats but don't quite understand what you mean about panels adding shade when you already have a rigid bimini.

[sailorchic34]

Even with my panels mounted aft, I use a preventer to pull the boom out a bit overboard, which reduces shaddows on the panel as the boat swings at anchor. So it's easy to make it work by moving the boom out from center with a preventer.

[Paul Elliott]

This is very similar to the arrangement on my boat: three 100W rigid panels on top of the dodger. They are wired in parallel and arranged port to starboard. I typically get 2/3 power, unless the boom shadow falls across two panels. I sometimes use the preventer to haul the boom way over so none of the panels are shaded.

This is far from optimal, but it works well enough for me. To my eyes a stern arch, while it would be better for the panels, would spoil the lines of the boat.

[Paul L]

Why not buy 2 or 3 smaller flex panels. Easier to ship, easier to wire how you want and easier to remove if needed.

[Drift Woods]

Installed two 100 watt flex panels last week. I decided to use two wired in parallel so when I'm sailing only one is boom shaded at a time. Tested it Saturday off Ft Lauderdale and it easily put out enough current to run my chartplotter, autopilot and small fridge.

Sent from my SAMSUNG-SM-G890A using Cruisers Sailing Forum mobile app

[roland stockham]

Thanks but it turns out to no go after all - More than $300 shipping charges. In the end my only option is to fit a single 195w panel as a 'flying wing' behind the stern arch as it is the only option available on the island and everything else costs a fortune to ship in to Aruba or Panama. Definitely need to sort it before the leg up the pacific as I don't want to be relying on engine charging, uses to much fuel.

[Paul L]

Where are you shipping from? I shipped from China direct using Aliexpress and the shipping was reasonable. They ended up charging the same shipping for one or 3 panels.

[roland stockham]

Originally Posted by Paul L

Where are you shipping from? I shipped from China direct using Aliexpress and the shipping was reasonable. They ended up charging the same shipping for one or 3 panels.

I wish, looking a shipping from china but their max delivery wt to Aruba is 2kg. I have just been talking to the supplies I wanted and they can do an alternative by shipping 2x100w panels to Canada. That would go on the plane as over sized baggage, question is will they come off in one piece!

[Paul L]

Originally Posted by roland stockham

I wish, looking a shipping from china but their max delivery wt to Aruba is 2kg. I have just been talking to the supplies I wanted and they can do an alternative by shipping 2x100w panels to Canada. That would go on the plane as over sized baggage, question is will they come off in one piece!

Are you heading to Panama? It is pretty easy to ship into Panama.

[roland stockham]

Originally Posted by Paul L

Are you heading to Panama? It is pretty easy to ship into Panama.

Yes, but they still want $150 to deliver a single panel which is have the cost of the complete setup if I get it direct from China. So finished up getting it delivered to Canada and taking it as checked baggage - should be fun!

[Lodbrog]

IT SEEMS COST IS PARAMOUNT. BUT SHIPPING REGARDLESS FROM WHERE IS CHEAPER AND EASIER THAN REFUELING OR A BUNCH OF 5 GALONERS STRAPPED TO THE SHROUDS. HAVE FUN GOING WEST.

[David B]

Originally Posted by Paul Elliott

This is very similar to the arrangement on my boat: three 100W rigid panels on top of the dodger. They are wired in parallel and arranged port to starboard. I typically get 2/3 power, unless the boom shadow falls across two panels. I sometimes use the preventer to haul the boom way over so none of the panels are shaded.

This is far from optimal, but it works well enough for me. To my eyes a stern arch, while it would be better for the panels, would spoil the lines of the boat.

There are a lot of different options out there, and some I have to say are at best, 'functional' at the expense of aesthetics. We spent quite a bit of time looking at various options that would work for us, and in the end went for an arch. The day came when we were committed - the angle grinder had attacked our pushpit and we just had to hope the end result was going to at least be 'OK'.

The final design I came up with was an arch curved (both X and Y) to match the curvature of our bimini supports and the 'targa' arch our boat comes with. On this, I mounted three semi-flexible 40W panels (looking down on them they curve aft as well as vertically i.e X-Y).

When finished, to us the aesthetics were enhanced (others may consider otherwise, but that's fine - we each have our views ), so we were much relieved about that.

Frankly, we love our arch - does so much more than hold panels (120w is all we need to keep things topped up when we are away - especially during winter storage). Our NAVTEX, WiFi, and 4G antennas all have a home now, and soon there will be a slim floodlight under there aimed aft in case of any 'issues' at night (a sonic cannon could be handy too ).

The below images show with and without canvas. If not for the OP, this might be useful for someone else attracted to this thread, who is considering options for their panels, antennas etc.

If you have a close look, we have also included davits as part of the arch. For our Zodiac (Fastroller 320) with outboard, this works beautifully, although for me, when we head off, I consider it needs to be lashed down on deck. Great however for quickly getting out of the water at the end of the day for security, when we are anchored.

Hope that helps someone,

David

[Mike OReilly]

I'm in the middle of an install that is very similar. In my case I'm using two 150 watt panels running fore to aft over the cockpit to act as a bimini. I'm wiring all panels in parallel under the assumption that one will be shaded most of the time.

I already have two 50 watt panels forward of the dodger on either side of the boom, wired in parallel. One side is usually shaded, leaving the other open to put out its full potential. For our needs, the additional 300 watts will make us self-sufficient, but my system is designed with the understanding that 1/2 of my panels will most often be shaded.