Engineering360: "Self-Fueling Boat to Circumnavigate the Globe"

Not exactly confidence instilling.

I guestimate about 12 or 13 kW worth of solar panels....but assume 15 kW just for fun.

Those vertical axis wind turbines aren't very efficient for their size and aren't very big to begin with....these will probably produce far more resistance to forward movement that offsetting power anytime going up wind.

The hydrogen by electrolysis has to be power from something....must be the solar panels.

Okay, so assume that all the solar power goes to propulsion either directly or via lossless batteries or lossless electrolysis and use of H2. Assume the equivalent of 8 hours of direct overhead clear sky sun every 24 hour period.

With those generous assumptions that allows an average of 5 kW or under 7 hp for propulsion of this sizeable boat. Just 7 hp.

Better stay away from gust winds and open water.

Assume double and 15 HP... That's rip roarin' in a canoe.

With a six year schedule they might be floating around with the prevailing winds and currents more than actual circumnavigation?

..now i need to look into it.. Thanks!

Might be better of with water turbines...Kinda silly.

I expect the 2 Vertical axis wind turbines will slip plenty enough wind to not be much of a drag detriment when cruising against the wind compared to the wind drag of the boats topsides.

Even though the turbines are fairly small they can produce significant power with higher wind speeds and will probably be working constantly with anything over 4 knots of wind.

The drag of the turbines relative to the drag of the remainder of what is topside is unimportant. The drag of the turbines relative to the power produced is critically important on headings other than downwind.

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Vertical axis wind turbines are notoriously poor performers relative to size. Additionally the blades are moving upwind half the time.

I doubt even very large vawt of the best design would be that much help. In fact I'm not sure any watercraft powered solely by VAWT and a propeller could make reliable headway straight upwind.

OK just for fun lets triple and say 15kW usable.

Maybe 15tonne fully provisioned and crewed.
Crosswinds according to the attached map between 11 and 14kts
It becomes patently obvious - the misprint in the article...6 years to get to Le Harve

The boat also features two vertical wind turbines that will produce around 3 kW of power, which is 1/10th of the power needed for the two electrical motors. Each turbine is 2 meters high and has been developed specifically for this boat.

Knowing something has been developed specifically for a certain application says nothing about whether it was a good idea, well designed, nor well executed.

Your tone suggests you might have some special insight into this project. If so, perhaps you can explain what we must be misunderstanding and why this is not a woefully underpowered vessel.

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Let's consider the VAWT first.

You say 2m tall and makes them about 1m across. So 2m2 area to the wind. Tell you what let's assume 1.5m across for a 3m2 area.

VAWT efficiency is about 10% for the better designs at optimum conditions. Let's say the ones on the boat are alien technology and are 25% more efficient that common human designs...so totalling 12.5% efficient.

Raw wind power is pretty close to 0.0006 x (velocity as m/s)3 = kilowatts per square meter. Multiply by efficiency to get power.

So, how fast does the wind have to be blowing to get 3 kW from this unbelievably perfect turbine?

3 kW from 3 m2 at 12.5% efficiency means the raw wind should contain 8 kW per m2

That corresponds to over a 40 knot wind.

If you think that 4 hp each will noticeably help control a boat t u is size in a 40 knot wind you are mistaken.

Were these turbines really installed with the idea that 40+knot wind would be typical everyday conditions?

This thing was meant to have the look of 'alternative energy, and I bet the VAWTs look pretty when turning. Just don't risk you life or anyone else's life with illplaced trust.

Ok it got the better of me I had to search...and
Its got a kite...you know kite sailing

Oh and air-conditioning and de-salination and 97% efficient electric motors and 2 x 4,322lt H tanks that store at 350 bar and "Two Storey H2O Compressors" (Can only presume it lost something in the translation - H2OCompressors being a company and Two Storey means two stage) to take the hydrogen from 30 bar to 350bar and this would require about 30kW and...
Got it...
They are gunna put the masts back in and use wind energy to ift the kevlar sails

BTW I hope someone some day really does do it - circumnavigate the globe with only renewables.
You know like them blokes (and a sheila for equality) Magellan, and Drake, and Cook, and Chichester and Jessica Watson - to name a few

I know this sounds crazy and probably impractical,but what if the vertical turbines had adjustable pitch vanes,that could use the head wind on one side to pull the blades,like an airplane wing.One side would push,the other side would pull.The timing and angle of the pitch,as well as the shape would be critical to proper operation.Controlled by a cpu and servos perhaps?

I can see it working in my mind,but do not have the facilities to experiment with it.

Would this work to improve efficiency?If not,why not?Jus' thinkin'

"... what if the vertical turbines had adjustable pitch vanes,..."

That is called a cycloturbine. Significant reasearch has gone into that concept.

I saw one of these "Eggbeater" style turbines in Oklahoma,back in the 1990's but I did not know how they functioned.

It was not being used,so I figure there must have been some problems.

It was still non-operable several years later.

There is always wind blowing in Oklahoma.

(One day the wind stopped blowing,and everyone in the state fell down.)

What is the latest data on this type of turbine?