Solar panels on the Bimini: flexible or rigid

[2airishuman]

My Tartan 3800 is a fairly average cruising monohull with a fairly average custom bimini made of Sunbrella and 1" stainless steel tubing. There's a split backstay that goes through zippers on the bimini. I want to add enough solar panels to keep up with the refrigeration, without introducing excessive windage, and without adding something that looks like a fucking tuna tower. That said, I don't race.

My choices as I see them are:

• I can put two rigid panels over the bimini, one athwartships in front of the backstays, and one athwartships behind them, using the fork mounts from geminiproducts.net and a subframe of 1" stainless tubing going fore and aft. The forward panel would be 200 watts and the aft panel 80 watts. These would end up being spaced about 1/2" from the bimini at the centerline and around 2" at the edges due to the bow of the bimini supports.
  
  
• I can attach semi-flexible panels onto the bimini adapting the techniques described here: https://www.sailrite.com/How-to-Install-Solar-Panels-on-a-Bimini

Either way I would reinforce the bimini frame to make it more rigid and able to support additional weight.

High-quality flexible panels from e.g. Soliban are extraordinarily expensive making this a more costly option although the extra costs of mounting hardware for rigid panels mitigates this somewhat. They don't last as long as rigid panels. On the other hand there's no windage and the panels are not visible when looking at the boat from any vantage point other than aloft. Also, output power is somewhat lower.

Cheap Chinese flexible panels are available but have burned more than one boat to the waterline so I'm taking a pass on those.

Advice and insights welcome.

My wife has already started with the flexible and rigid penis jokes but if that's all you have to add to the discussion I'm not wasting a downvote.

 

[slug zitski]

What ever you choose don’t spent too much money

a dodger is a very poor panel location

shadowed by boom, sails , mast , rigging ….

 

[gptyk]

I have 2 200w Ridgid panels on the Bimini. Mounted fore/aft so the panel helps make the Bimini a bit more rigid. Beefed it up by making all mounts rigid (no straps). On a dodger I'd go flex.

 

[2airishuman]

What’re you choose don’t spent too much money

a dodger is a very poor panel location

shadowed by boom, sails , mast , rigging ….

Slug I'm talking about the bimini not the dodger. Front of the bimini on this boat clears the aft end of the boom by 4". Backstay is the only significant source of shadows.

 

[El Borracho]

Yes. Bimini is a great place. Mine wasn’t braced. Rigid are fine there. Could wobble a bit side-to-side but wasn’t a problem. Bonus is it keeps the canvas cooler in the tropics so your head doesn’t fry when standing there.

Dodger is a good enough place too. The boom can be moved whilst sailing or parked.

 

[Jud - s/v Sputnik]

They don't last as long as rigid panels. On the other hand there's no windage and the panels are not visible

I would’ve thought that, with a bimini, you’re already well on the way to “crap on the back”, so the difference between rigid vs. flexi likely negligible in terms of windage

 

[DDW]

If you want a one or two year solution, flexible. If you want a 10 or 20 year solution rigid. The flexible panels have a very short life span.

 

[IStream]

This. Rigid is the way to go unless you absolutely positively have to have the low profile and low weight of flexis. After 10 or 15 years, you'll have paid 5X-10X more for the flexis for equivalent output.

 

[Hale Moana]

I went with rigid panels. There are three 65 watt panels on the dodger and one 65 watt panel on SS 1" tubing that extends aft from the dodger to an athwartships arch. I could add a 5th panel if I wanted to but so far have not felt like I need another panel. The cockpit sunshade fits under the aft panel. I have a rigid boom vang that supports the boom to keep it above the panels. I had one panel to start with and it would keep up with the frig draw during the day. When I replaced the cloth dodger with a hard dodger I added three more panels. Since then the panels supply all of my electricity. Unless it is cloudy for more than a day or two. I keep the boom offset to one side at anchor or on the mooring. Backstay and boom shading has not been a problem.

 

[Jim in Halifax]

I went with the cheap Chinese flexible panels as an experiment. The boat never burned down but a hurricane ate it. I had 2 x 100 w panels on the bimini. They worked fine to keep the fridge running and the lights on. One was replaced under warranty after the first year. I still have both panels in service on my new boat, four years later. If I was going offshore to remote destinations, I would probably buy Soliban panels. The ease of removing and stowing flexible panels means that its quick to strike the bimini and dodger in the event of storms and hurricanes. My $0.02 anyway.

 

[eliboat]

I went with rigid panels. There are three 65 watt panels on the dodger and one 65 watt panel on SS 1" tubing that extends aft from the dodger to an athwartships arch. I could add a 5th panel if I wanted to but so far have not felt like I need another panel. The cockpit sunshade fits under the aft panel. I have a rigid boom vang that supports the boom to keep it above the panels. I had one panel to start with and it would keep up with the frig draw during the day. When I replaced the cloth dodger with a hard dodger I added three more panels. Since then the panels supply all of my electricity. Unless it is cloudy for more than a day or two. I keep the boom offset to one side at anchor or on the mooring. Backstay and boom shading has not been a problem.


View attachment 552853

I put a flexible panel on the coach top. Sits flat on the deck and gets great sun for most of the day without adding any clutter. I quoted the above post to point out the area starboard side just forward of the companionway slide. My boat is bigger, however the above example would work well too. Slug is correct about shading on a dodger and possibly a Bimini, depending on arrangement. Even a backstay shadow can destroy your production.

 

[billsreef]

I have 2 200w Ridgid panels on the Bimini. Mounted fore/aft so the panel helps make the Bimini a bit more rigid. Beefed it up by making all mounts rigid (no straps). On a dodger I'd go flex.

Yes. Bimini is a great place. Mine wasn’t braced. Rigid are fine there. Could wobble a bit side-to-side but wasn’t a problem. Bonus is it keeps the canvas cooler in the tropics so your head doesn’t fry when standing there.

Dodger is a good enough place too. The boom can be moved whilst sailing or parked.

How did you guys deal with Bimini canvas and mounting?

 

[Jim in Halifax]

How did you guys deal with Bimini canvas and mounting?

With flexible panels, Velcro is a slick way to do it. A good article is on the Mainesail (Marine How To) site. I just lashed mine as a temporary trial.

 

[El Borracho]

How did you guys deal with Bimini canvas and mounting?

Holes in the canvas for screws thru the tube. Kinda agricultural but was fine. It was a previous owner thing. Better to use some clamps to hold an alloy crosspiece. Make a nice hemmed hole in the bimini.

Got rid of the bimini and dodger somewhere in the islands. Didn’t suit my rugged aesthetic.

 

[low bum]

If you want the bimini to be easily retractable, then flexis will be easier to live with. If you're cool with the bimini being virtually permanent, or are cool with the hassle of nuts and bolts and inconvenience, then always go with rigid. The flexis are going to sit up there and flop and flex and die out.

 

[low bum]

How did you guys deal with Bimini canvas and mounting?

To my mind, zippers are the way to go. Easy on, easy off. Far more resistant to wind getting under the panel. There is a good German product that is a sort of snap on push button grommet deal, not cheap, but still allows for a lot more flopping.

 

[gptyk]

How did you guys deal with Bimini canvas and mounting?

Grommets for the mounting posts. My Bimini never comes down

 

[Hale Moana]

Shading problems depend on how the panel is wired. With the old style panels one thin shade line like from a backstay would stop the panel from producing any power. My panels are wired such that shade over part of the panel only affects the cells that are shaded and the rest of the cells still produce power.

 

[El Borracho]

… With the old style panels one thin shade line like from a backstay would stop the panel from producing any power.

Disagree. I had ancient panels. Heard the folklore horror stories about shade by wires. Never observed it. Maybe the tropical sun is hazy enough, or the blue sky bright enough, to keep all the silicon junctions working. Whatever the horror is, I never noticed it happening. Worked with shadow lines just fine for me.

Never experienced data sheet performance either. Good enough.

 

[Grith]

We went both ways to achieve enough solar power to eliminate gas cooking and refrigeration onboard despite only being a28 foot long trailable. Yes we look like a sailing caravan not a racing yacht but that’s what our use is.