Solar panels built into sails... good idea or bad?

Not convinced...

You can already get leccy from sails... Via a towed generator.
You can already get leccy from the sun... Via normal solar panels.

Sure, but the former increases drag and the latter is limited in size. I do agree that cost will be critical, but look at the scale PV manufacturing and generation sector where real costs have collapsed through innovation and mass production. Start-up technologies often follow an "S" curve; no reason to assume that this will be much different.
 
Sure, but the former increases drag and the latter is limited in size. I do agree that cost will be critical, but look at the scale PV manufacturing and generation sector where real costs have collapsed through innovation and mass production. Start-up technologies often follow an "S" curve; no reason to assume that this will be much different.

I think the point I am trying to make is that this is a cure looking for a problem.... With new led lights, lower power instruments, etc... There are good opportunities to reduce consumption..

Costs associated with producing leccy is coming down, solar is cheaper, and wind is as well...

So unless they can do this at a very low cost, I just can't see how it would be attractive over the existing techs... Which are getting better and cheaper....
 
Maybe not solar panels, because as has been said the angle isn't great (unless you are heeled right over !), but think of the very powerful wind forces acting on the sails... If they were made of a material that generated electricity just by distortion and stretch, then we might keep the sails out even in very light breezes and we would remember the joys (and skills) of sailing slowly and peacefully, rather than turning on the engine as soon as the wind drops.

And of course there is lots of research developing dielectric elastomers and piezoelectric generators woven into materials...
But I hope all the extra electricity generated will not be used for blue lights under the waterline !
 
This is interesting. About 5 years ago I attended a talk given by researchers at Heriot Watt University. They were developing fabric that would also act as a photo voltaic generator. Their planned application was tents for disaster relief, but my immediate thought was sails, where there's probably more money to be made. The available sail area of an average cruising boat is one or more orders of magnitude greater than the area of conventional solar panels that can be fixed to the hull, so non-optimal angles etc. is probably not a big issue.

There's also something rather nice about the idea that the more you sail rather than motor the more free electricity you harvest. :)
 
I think the point I am trying to make is that this is a cure looking for a problem.... With new led lights, lower power instruments, etc... There are good opportunities to reduce consumption..

Costs associated with producing leccy is coming down, solar is cheaper, and wind is as well...

So unless they can do this at a very low cost, I just can't see how it would be attractive over the existing techs... Which are getting better and cheaper....

Photodog,

maybe, but I look forward to the day when electric propulsion is viable for yachts - yes I know it's not green really considering the production of batteries but I'm being selfish.

When considering building new Anderson 22's I was very keen on having an electric engine, but after chatting with a Torqueedo engineer I realised it's still only possible with a boat designed for it, something like a long keeler using the batteries as ballast - still close to a U-Boat !

However with photovoltaic sails I'm sure silent and high torque ( auxilliary ) propulsion will happen one day.
 
Photodog,

maybe, but I look forward to the day when electric propulsion is viable for yachts - yes I know it's not green really considering the production of batteries but I'm being selfish.

When considering building new Anderson 22's I was very keen on having an electric engine, but after chatting with a Torqueedo engineer I realised it's still only possible with a boat designed for it, something like a long keeler using the batteries as ballast - still close to a U-Boat !

However with photovoltaic sails I'm sure silent and high torque ( auxilliary ) propulsion will happen one day.

S'wot I said earlier. I'm sure the day will come either with advanced battery technology or compact fuel cells which can be recharged by solar power

Thirty years ago a computer in your pocket that could run for days without recharging and connect to virtually anywhere in the world from virtually anywhere in the world was all but inconceivable - hell, we'd only just got over the launch of digital watches and pocket calculators! Since it's technically possible to generate hydrogen from seawater using electricity generated by solar power and to then use that hydrogen in a fuel cell to create power to drive an electric motor, turning it into a workable and economically viable package is just engineering.

It will happen when there's a big enough market willing to pay a high enough price and that day will come, as it surely must, when the cost of fossil fuel for use in internal combustion engines goes through the roof (that day will come, probably not in my lifetime, maybe not in the lifetime of my children but within a matter of two or three generations. That's the real issue behind the profligate use of fossil fuels by our generation, never mind the whole MMGW thing)
 
Since it's technically possible to generate hydrogen from seawater using electricity generated by solar power and to then use that hydrogen in a fuel cell to create power to drive an electric motor, turning it into a workable and economically viable package is just engineering.

The problem with that model is that electrolysis of water to make hydrogen and oxygen is horribly inefficient at usable rates (at very low rates it's endothermic and therefore > 100% efficient as far as electrical input goes) and that storing the gases produced ain't easy unless you compress them, and even then it ain't easy. Basically, going from electricity to hydrogen just doesn't make thermodynamic, economic or engineering sense.

Better and cheaper batteries are the thing to hope for. When a battery pack for a Tesla costs £5k instead of £50k, we'll be getting somewhere.

I know someone who is converting a Victoria 800 to electric propulsion. He has made a very neat job of it, using a Lynch motor and (iirc) two 200Ah lead acid traction batteries. For the same weight he could fit around 8 Mastervolt 5000Wh lithium ion batteries which would give around ten times the current (haha) capacity ... but alas at a cost of around £35k for the batteries.
 
The problem with that model is that electrolysis of water to make hydrogen and oxygen is horribly inefficient at usable rates (at very low rates it's endothermic and therefore > 100% efficient as far as electrical input goes) and that storing the gases produced ain't easy unless you compress them, and even then it ain't easy. Basically, going from electricity to hydrogen just doesn't make thermodynamic, economic or engineering sense.

At that sort of scale you're likely as not right but it was just an example

Better and cheaper batteries are the thing to hope for. When a battery pack for a Tesla costs £5k instead of £50k, we'll be getting somewhere.

I know someone who is converting a Victoria 800 to electric propulsion. He has made a very neat job of it, using a Lynch motor and (iirc) two 200Ah lead acid traction batteries. For the same weight he could fit around 8 Mastervolt 5000Wh lithium ion batteries which would give around ten times the current (haha) capacity ... but alas at a cost of around £35k for the batteries.

That's more the sort of tech that will eventually get the job done. Although L-Ion does have it's issues

But however it ends up turning out - whether an improvement on existing technology or something new and better - as sure as eggs is eggs the future is electric. The only real question is when, not if
 
Erbas,

I agree, ' when not if '.

Jumbleduck,

any idea of the range / endurance your chum will get from his electric Victoria ?

When I chatted with the man from Torqueedo he reckoned it would take the ballast weight of the boat even with their moderately high tec batteries to be viable; then maybe he was trying to get ' battery salesman of the year ' !
 
any idea of the range / endurance your chum will get from his electric Victoria ?

From memory, about 20 minutes at full power (6 kt) and about 4 hours at a gentle cruise (3kt?). That's hoped for - the system needs a fair bit of tuning and a believe a new prop is on its way.
 
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