Solar sail for saiboat

[Ambroise]

Hello, as part of a project, I am conducting a market study on a potential solar sail. I would like to know if individuals or professionals who own sailboats would be interested in the concept.


The idea would be to have, in the near future, a kit that can be adapted to each sailboat, providing a solar sail connected to a battery on the boat. This sail would provide power to an auxiliary motor in case of no wind. It would also power onboard systems such as lighting, navigation instruments, pumps, and more.
The kit could also offer sailboat electrification services, such as an electric bilge pumping system or replacing manual pumps with electric ones.


Your opinion is highly valuable, so please don't hesitate to respond or ask questions!

[Nicholson58]

The angle relative to incident solar will be both wrong and not adjustable.

Such a sail p, given current flex panel characteristics, is too stiff to flake and cannot be in boom or in mast furled.

Flex panels are too heavy and would destroy or at least interfere with proper sail shape.

Existing flat panels are relatively inexpensive and are quite high efficiency. Some exceeding 25%.

Some flex panels are currently used on Bimini soft tops.

My opinion, not remotely practical with current tech.

[BlackOak]

I can see this a good working option. Flexible panels sewn into the sail like battens, or a zippered pouch sewn on the sail to slide in the panels.

https://www.sailorsforthesea.org/blog/solar-sailing

[Statistical]

Sure it would be the holygrail. Even if efficiency is low supplementing other solar with a sail that can produce power would be amazing. The square footage could overcome a huge amount of inefficiencies.

However sails are subject to certain material requirements. They need to be conformed to a certain shape to maximize efficiency (wind power to lift), they are subject to tremendous forces, they have to handle at times luffing (rippling/snapping in the wind), they remain packed for extended periods of time.

Even if you limited yourself convention battened mainsails it would be a challenge. The panels would need to be flexible enough to not interfere in the usage of the sail and also flake (fold) properly for storage on the boom.

If you could do it the market would be huge as most sailboats are limited in available horizontal deck space. I remain skeptical it is possible without compromising the function of the sail at any reasonable prices.

[Adelie]

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[Rohan]

The idea is fantastic, but so many drawbacks to overcome.

1. I assume it would only work while sailing. How much time is actually spent under sail? Even hard-core cruisers spend most of their time at anchor. In my experience, we are using at lot more electrical power at anchor (TV, cooking, etc) than while sailing. Although I'm thinking that in a light wind, even while at anchor or in a marina, I could raise/haulout the sails a bit to supplement the electrical power, which would be useful.

2. Weight - how light would they be compared to canvas? I have flexible panels on my boat and they are pretty light, but still weigh a heck of a lot more than a section of sail the same size. And solar sails would have to be basically DOUBLE that, to be able to collect on both sides. Also, it puts the weight up high, just where a sailboat doesn't need it.

3. Rigidity - how flexible can they be? While close hauled, sails are more like wings, but on a reach they also propel the boat by catching the wind, and in that case they need to be flexible. Solar sails might work well on racing boats like America's cup racers, I believe their sails are much more like wings and remain rigid all the time (I could be wrong on this, but that's how it appears). Also, depending on the rigidity, it may not be possible to use an in-mast furler.

[boatman61]

I imagine it's feasible on hard wing sails with rotating masts, on conventional rigs however too many factors to make it viable with current tech/materials.