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Solar-powered aircraft flown for nearly three weeks without landing

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Re: Solar-powered aircraft flown for nearly three weeks without landing

#171

Post by jacquesm »

goldenkey wrote: post #121
Stevvo wrote: post #117

Earlier quoted context omitted.

I have a 38' steel sloop with 400w of solar + a wind generator on-board. I'm not a full-time liveaboard, but I have been on-board for the last couple of months and you can definitely make it work. Sailing is labor intensive, but not in the ways you imagine. Navigation, docking and provisioning are all straightforward. Where it can sometimes feel like a full-time job is maintenance. Everything on a boat wants to break…

I learned a few years ago about barnacles, which by virtue of being unaerodynamic and super heavy if you let them form huge colonies on the bottom of your ship, can decrease fuel efficiency severely. I saw how much work maintanence was, I said 'nope!' I guess a house is similar in some ways. Shingles don't last forever, pipes get corroded. The salty sea though, it's a bit more unkind to things, aye?

Compared to a house an ocean going (so salt water) sailboat disintegrates while you're looking at it. A sweet water boat a bit less fast but still quite fast. GP has it right: the maintenance is where the work and the money goes. The proverb is "a boat is a hole in the water that you throw money in".

Re: Solar-powered aircraft flown for nearly three weeks without landing

#172

Post by jacquesm »

joshuagross wrote: post #170
rootusrootus wrote: post #147

Earlier quoted context omitted.

For sure. Even then, the techniques used by builders at the beach seem to allow houses to endure a long time.

You’ve gotta replace some stuff yearly on those houses by ocean spray, it’s actually a bigger problem than it might seem

Absolutely. I once looked at an apartment on IJmuiden beach, it was only a few years old and it looked as if it was 50 years old (and had not been maintained in those 50 years).

Re: Solar-powered aircraft flown for nearly three weeks without landing

#173

Post by jacquesm »

pomian wrote: post #161
stareatgoats wrote: post #24

This is great and points to how solar in some cases already can facilitate continuous operation without the need for refueling of planes, boats, cars, you name it. Expect this to grow as battery and solar cell tech develops further. My favorites atm are the yachts that are capable of sailing just about anywhere in the world without a drop of fuel. The price is prohibitive, but considering that you might not need a ho…

Most sea going sailboats, and many others, are perfectly capable of sailing around the world, without any fuel. Solar panels are only needed to charge batteries, that are only needed if you want the extras: GPS, radio, other communications. 2 panels and 2 batteries are good enough for most boats, for 1 to 4 persons, traveling for anywhere around 1-2 months across the seas. The limitations are water, and food storage.…

That's the entry fee. And then the real cost starts to roll in. There is a reason so many Youtube channels and Patreon accounts are being used to fund otherwise unviable life-styles of people sailing full time.

Re: Solar-powered aircraft flown for nearly three weeks without landing

#174

Post by jacquesm »

zapdrive wrote: post #166
pomian wrote: post #161

Earlier quoted context omitted.

Most sea going sailboats, and many others, are perfectly capable of sailing around the world, without any fuel. Solar panels are only needed to charge batteries, that are only needed if you want the extras: GPS, radio, other communications. 2 panels and 2 batteries are good enough for most boats, for 1 to 4 persons, traveling for anywhere around 1-2 months across the seas. The limitations are water, and food storage.…

Food can be stored longer by refrigeration, which requires power. Similarly water can be desalinated, which again requires power. Solar & batteries can help with both of these.

On a typical sailboat space is very much at a premium, even de-hydrated foods occupy quite a bit of room.

Re: Solar-powered aircraft flown for nearly three weeks without landing

#175

Post by jacquesm »

javajosh wrote: post #145
silisili wrote: post #132

Earlier quoted context omitted.

Interesting last point...curious why is that? Do they get battered from weather and physically tear, or do they just stretch/thin over time?

Racers use very thin, light, and stiff sails made from mylar or similar materials. They are typically very expensive and want to be changed as often as possible, at least once every racing season. Modern small pleasure yacht cruising sails "canvas" is laminated polyester, aka dacron, which is far thicker, more durable, springier, and more common than mylar. It's an interesting question, where does the wear come from.…

This is all spot on. Sails fail due to wear of the fabric itself, because a seam failed, from rubbing, repeated stretching and releasing (you can tell an older sail because it will bulge more as a result of this) or because it got over-stressed. Salt water obviously also doesn't help with sail fabric longevity, as does UV influence all of which will age a sail (check the color difference on spare sails that have been bagged vs the ones in use or, check the first strip of a roll-up sail to see how much that can affect the fabric).

Those areas where the sail needs to be strongest is where they are re-inforced doubling up the layers (and not just 'two', a corner can easily be 10 ply or more thick), on older boats further re-inforced with leather or heavier grades of fabric. The panels are carefully laid out so that the highest stress aligns with the warps. A large sail can be made up from many 10's of panels, which are joined in a variety of manners (glue (typically for very fast boats or as re-inforcement of stitching), stitching, sometimes ultrasonic welding for special applications). On the very high end there are even laminated custom laid out fibre pattern sails (for instance: a sandwich of Kevlar wire between two layers of bonded fabric or plastic).

At one time I worked for a competitor of North Sails, who by the way were pioneers in the digitization of sail manufacturing.

Re: Solar-powered aircraft flown for nearly three weeks without landing

#176

Post by saberdancer »

pbhjpbhj wrote: post #69
Retric wrote: post #56

Earlier quoted context omitted.

Sails have several major downsides, most notably they take up a lot of deck space and cause a boat to tilt to the side. If you’re regularly sailing long distances it’s much faster but top speed isn’t that big of a deal when your living on the boat full time. Other options like kites and wind turbines can work well but they all all significant upfront costs as well as ongoing maintenance issues. Spending that same mon…

>top speed isn’t that big of a deal when your living on the boat full time.// If you're living on your boat 365 then I imagine avoiding severe weather becomes more important?

You are right but it depends on the skillset and general lifestyle needs of the person. I've watched (a little) some of the sail around the world channels on YouTube and one couple moved to a performance trimaran, the guys reasoning was that he wanted to have speed to get out of the way if the weather changed.

For those that do not really stray far from the shore or who are willing to take more risk for more comfort, they use a slower boat.

Re: Solar-powered aircraft flown for nearly three weeks without landing

#177

Post by Abishek_Muthian »

stareatgoats wrote: post #24

This is great and points to how solar in some cases already can facilitate continuous operation without the need for refueling of planes, boats, cars, you name it. Expect this to grow as battery and solar cell tech develops further. My favorites atm are the yachts that are capable of sailing just about anywhere in the world without a drop of fuel. The price is prohibitive, but considering that you might not need a ho…

Solar yatchs are cool!

Considering loitering is a very important goal for military drones, I expect them to be using solar power extensively too.

Re: Solar-powered aircraft flown for nearly three weeks without landing

#179

Post by sneak »

ncmncm wrote: post #169
emkoemko wrote: post #167

Earlier quoted context omitted.

that crap should be banned... if only rich folk can do these trades it is not fair for everyone else.

Or anyway taxed.

The profit from trading securities is definitely already taxed.

Re: Solar-powered aircraft flown for nearly three weeks without landing

#180

Post by GeorgeOu »

mattlondon wrote: post #100
stareatgoats wrote: post #24

This is great and points to how solar in some cases already can facilitate continuous operation without the need for refueling of planes, boats, cars, you name it. Expect this to grow as battery and solar cell tech develops further. My favorites atm are the yachts that are capable of sailing just about anywhere in the world without a drop of fuel. The price is prohibitive, but considering that you might not need a ho…

I've always been kinda fascinated by this solar yacht concept. I wonder now with post-covid remote working options and starlink if you could actually make it work. I do wonder though if sailing the ship is basically a full-time job in itself (navigation channels? Docking at foreign countries? Getting food etc?).

Yachts don't rely on solar. Sometimes they have solar but only as a small auxilary system. They primarily rely on propeller regen where the prop flips into drag mode stealing a fraction of a knot from the sail-driven ship. I've seen some yacht owners try to install a small wind turbine but it's not worth the trouble because of the noise it creates. They also tend to have at least one gas generator as an emergency backup.
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