New offshore turbine design to create and store energy

Wouldn't this new broad design be susceptible to large waves crashing into it???

Without kneejerk knocking the article or the technology, I've got to say that I'm not sure how "new" this design is.

I've seen this type of windmill before (and "windmill" it is, even though the article tries to make a distinction), and in fact there's a very nice looking one very much like this installed at the "da Vinci School" in Dallas, Texas. I'd post a link except the school is new enough that as of today both Google Street View and Bing Birdseye View still show the school either under construction or as an empty lot.

Plus, why trumpet that it will be "built without the need for a... transmission line...", as if that's a plus, when the last sentence reveals they mean "without the need for an ADDITIONAL transmission line". So is this limited to locations with existing undersea cables? I'd guess not - but if you built it elsewhere you'd loose one third of your opening paragraph's "new design" stated benefits.

It sounds cool enough, I guess, so why pad the benefits?

On balance, I should probably add: "Nevertheless, I still want one."

Slight problem with the first video...someone will run over it with a boat. No reflective markers or lights.

@capitalism prevails - See the lines holding the bottom? Just like those tall tall thin radio towers that are extremely thin and have highspeed winds buffeting the top. Using tensile lines is more secure than you think.

I have no opinion on the feasibility. I just decided to post some relevant data that was completely missing from the Physorg SeaTwirl commercial, cough, cough, er article, cough, cough.

From the Seatwirl pdf:

Specifications
A large unit could be built with the following
specifications:
Rated power: 10 MW, Mean power: 4.5 MW
Yearly production: 39 000 MWh, Sweep area: 24
000 m2.
Energy storage: 25 000 kWh, could support 8000
households during 1 hour.
Height from water level: 210 m, Depth from water
level: 228 m

The picture at the top of the article is from the pdf and has the following caption:

FIGURE 2: A cross sectional figure showing parts of
the SeaTwirl. The upper part consists of a vertical
axis wind turbine hold by wires and a surrounding
torus ring positioned 30 meters above water level.
The rotating body stretching all the way down to the
rotating generator, blue part.

I CAN IMAGINE AN OIL TANKER RAMMING A FARM OF THESE :)

Sweep area: 24000 m2.

That would mean a diameter for the rotor of about 175 meters. If it's really going to have a height of 210 m above water, then it would look much taller than it is wide. Also, if underwater part is 228 m then it's roughly halfway in/out of water, whereas in the illustration and movies it looks more like 1/3 above water and 2/3 submerged, looking a lot more stable to the eye. In these respects, the pictures/movies are a bit deceptive.

As for the feasibility of creating wind load-bearing structures of that scale, consider that a state of the art "classical" 5 MW offshore wind turbine has blades about 60 m long (so "windmill" diameter is about 120 m) with the blades having to be ultra-light and ultra-strong (constructed with heavy use of composites).

It'll be interesting to see if this goes anywhere, and how it fares at realistic scales in field trials.

anything built in the ocean will get destroyed by the ocean and is at all times extremely vulnerable.

I wonder why no one has built a wind turbine shaped like a mobius strip. It is supposed to be the quietest and most efficient shape to make a fan out of. I read an article about the benefits of this shape many years ago.

the mooring lines are only attached at the bottom. so the central shaft, even if it's inflexible and buoyant will tilt from that point in heavy wind or current and the downwind blades will be submerged. also seawater in contact with the spinning shaft will create drag just like a sailboat. possibly less than bearings though unless it gets covered with corrosion and seaweed.