Giant Floating Windmills To Launch Next Year

pacroon writes "StatoilHydro is building the world's first full-scale floating wind turbine, Hywind, and testing it over a two-year period offshore of Karmøy, Norway. The company is investing approximately $80 million. Planned startup is in the fall of 2009. The project combines existing technology in innovative ways. A 2.3-MW wind turbine is attached to the top of a so-called Spar-buoy, a solution familiar from production platforms and offshore loading buoys. A model 3 meters tall has already been tested successfully in a wave simulator. The goal of the pilot is to qualify the technology and reduce costs to a level that will mean that floating wind turbines can compete with other energy sources."

Comments

Re:Are the masts designed to fold under extreme wi

[polar red]

the latest generation of windmills produce electricity by wind speeds up to 30m/s, and at higher speeds, they just turn the blades out of the wind, so they won't get damaged.

Bats seem to have a real problem with them

[Shivetya]

Here is an old article I remembered about and fortunately google brought it up http://www.coxwashington.com/reporters/content/reporters/stories/2005/11/13/BC_WINDMILLS_BATS_ADV13_COX.html

From the article
" Towering up to 228 feet above the Appalachian Mountain ridge, far above the tree line, windmills are lined up like marching aliens from War of the Worlds.
Up close, they emit a high-pitched electrical hum. From a distance of a few hundred yards, their 115-foot blades make a steady whooshing sound as their tips cut through the air at up to 140 mph."

"A study conducted at FPL's Mountaineer Wind Energy Center here this year indicated that its 44 turbines may have caused between 1,300 and 2,000 bat deaths in a six-week period. That study was led by Edward B. Arnett, a scientist with Bat Conservation International, and financed largely by the American Wind Energy Association and its 700 member companies."

Re:Transmission?

[William Robinson]

The raft wont be floating freely, it will be anchored to a specific spot

Thanks.

I found a better article that explains the concept with better pictures.

Re:Transmission?

[Anonymous Coward]

>How exactly they are going to manage a good reliable power transmission
>with the kind of floating power station, Any idea?

The subsurface structure:
Water depth: about 220 m (approx. 720 ft); buouy is a cylinder standing vertical in the water, the draft is about 100 m (305 ft);- buoy diameter, say 10 m.

Topside structure/turbine data:
Operating wind speed: 3-27 m/s; about 40 m long blades; rated capacity and speed: 2.3 MW; 5-15 rpm.

Mooring system:
Attached to buoy at about mid-point (say at depth 50 m); 3 mooring lines.

The power transmission system, the electrical cable:
The cable is attached to the buoy at either depth 50 m or at buoy bottom. The buoy will be subjected to both dynamic and static motion due to waves, currents and wind. The static motion is mainly horizontal offset caused by the static loads that are counteracted by the mooring system. The cable arrangement is able to adjust to these buoy motions without mechanical overload, this is achieved by the following methods:
1. Bend stiffener in the interface with the buoy (a 2-3 m long conical plastic thing which main purpose is to avoid overbending and associated fatigue damage in the interface with the buoy.
2. The cable is arranged in a compliant riser configuration between seabed and buoy, this allows the spar buoy to move without causing excessive tension and bending in the cable. This effect is achieved by "storing" over-lenght in a buoyant cable section. Hence - when the buoy moves - cable lenght is simply "paid" out (or in) from the buoyant section. Starting at the buoy there is a bend stiffener followed by say 150 m cable, then perhaps 60 m cable equipped with buoyancy until eventually there is cable to the seabed. There is of course an anchor somewhere at the seabed to keep the cable fixed.

The above technology is well known from the oil industry, the described riser configuration is a so called "pliant wave" or "lazy wave configuration". The main challenges with this concept is that it is new uncharted territory and that we do not yet know the actual parameters. Our experience is from the oil business, where such cables between platform and seabed are routinely used.

Greetings from a member of the engineering team within Nexans Norway AS, the Halden plant, which will design and manufacture the power transmission for the Hywind project.