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Clean Power floating wind turbines

Published on July 7th, 2014 | by Tina Casey


Floating Wind Turbines Float Into US Waters (Finally!)

July 7th, 2014 by  

The US has been lagging badly while other countries spring ahead with offshore wind farms, but it when it comes to the niche sector of floating wind turbines we’re right up there with the front-runners. That’s according to a recent article in The Guardian, which mentioned a US floating wind turbine demonstration project at Coos Bay off the Oregon coast in the course of an article on Portugal’s cutting edge floating wind turbine experiments.

We touched on that Coos Bay project earlier this year, so now would be a good time to take a closer look.

floating wind turbines

WindFloat floating wind turbine from Principle Power via US DOE.

Why Floating Wind Turbines?

Regarding that thing about the US lagging globally, the east coast of the US is actually starting to rev up its considerable shallow-water offshore wind power potential.

A multistate east coast offshore wind consortium to coordinate the effort got under way in 2010, and a jump-up-and-down milestone just occurred last week when the Energy Department gave its conditional blessing to a $150 million loan guarantee for the massive Cape Wind offshore wind farm in Massachusetts. A Rhode Island offshore wind farm is also set for completion in 2016.

The west coast of the US is a different story. The Continental Shelf drops off steeply, leaving little room for shallow-water offshore turbines anchored on conventional platforms in the ocean floor.

The solution is to float platforms for wind turbines in deep water and tether them in place. While that sounds simple enough, when you consider the massive scale of wind turbines and the rough-and-tumble of deepwater conditions, engineering a durable, cost-effective platform is a huge challenge.

However, there is a juicy payoff in the form of more powerful, steady winds.

The Guardian’s floating wind turbine article also credits a knowledge base of engineering for deep water drilling operations, which has helped to accelerate the development of floating wind turbines.

The Principle Power Floating Wind Turbine

The Coos Bay wind power project, called WindFloat Pacific, will be the west coast’s first ever offshore wind farm. It is being developed by the aptly named company Deepwater Wind (not to be confused with DeepWind), using the WindFloat floating wind turbine technology provided by Principle Power, the same company behind one of the Portuguese projects.

Many other stakeholders, including Energy Department labs, are also involved in the project.

Principle is focusing first on the US and Europe wind markets, where previously untapped sites have the potential for more than two terawatts of wind power (btw if Deepwater rings a bell, that’s the same company behind the fixed-platform Block Island wind farm, which will most likely be the first offshore wind farm to operate on the East Coast).

We first took note of Principle’s distinctive three-cornered floating platform back in 2009, when it received a $750,000 Energy Department grant to incorporate wave energy into the structure.

The relatively simple part of the WindFloat equation is the mooring system that connects the platform to anchors on the ocean floor, which is composed of chain and polyester lines typically used in mooring operations of that type.

According to Principle, the system is operational at depths of greater than 60 meters.

A lot of attention also went into designing the WindFloat platform so that it could be full assembled onshore and then towed to its final destination, in order to reduce construction costs as well as risk exposure.

That meant designing a platform with a very shallow draft (draft refers to the part of a watercraft that remains under water), enabling it to be shipped from shallow waters to the deep.

Two key aspects of the WindFloat consist of a special “closed loop” hull trim design and proprietary plates at the base of each of the three columns. Called water entrapment plates or  heave plates, they are designed to stabilize the platform against wave action, while the hull trim works against changes in wind velocity.

The improved stability enables the turbines to operate more efficiently. It also enables the WindFloat to employ standard onshore wind turbines, which are being provided by Siemens.

Many Cooks In The Floating Wind Power Broth

The next time we checked on Principle Power was just this past spring, when WindFloat and the Coos Bay project made the cut for one of three competitive Energy Department grants for advanced offshore wind power technology.

The other two projects are for New Jersey and Virginia, so now would be a good time to travel back to the east coast and see how offshore wind power has managed to crank up there, despite the usual Koch-related shenanigans.

In New Jersey, we’re just guessing that Governor Chris Christie’s friendly relations with the Koch brothers played a role in his decision to have his state effectively sit out the aforementioned east coast offshore wind consortium.

However, offshore wind is coming to New Jersey whether the Governor likes it or not, in the form of an Energy Department-funded five-megawatt demonstration wind farm, to be built by Fisherman’s Energy off the coast of Atlantic City.

Massachusetts also had a Koch monkey wrench thrown into its offshore wind sector, spearheaded by William Koch (the “other” brother). Koch was the main funder behind a years-long legal battle to stop the Cape Wind project, but earlier this year the final decision went in favor of wind.


With the legal stamp of approval in hand, just last week, the Energy Department gave its conditional approval to the $150 million loan guarantee to get Cape Wind off the ground and into the water.

Another east coast state that has apparently come under the Koch influence is Maine, through the conservative lobbying organization ALEC. The Guardian article referenced how Governor Paul LePage torpedoed and already-signed deal to bring global offshore wind power leader Statoil onto a $200 million wind development project, in favor of a more modest effort spearheaded by the University of Maine.

As of this count, Maine and New Jersey are still a wash but between the Oregon offshore floating wind turbines and the east coast activity, it looks like the sleeping US offshore wind power giant is finally waking up.

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About the Author

specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. Views expressed are her own. Follow her on Twitter @TinaMCasey and Google+.

  • Fernando Carrera

    Under de floating wind turbine, install a Hydro turbine can be hung helping to stabilize and obtain additional power.

    • CaptD

      Yes and share the same cable to shore…

  • Ronald Brakels

    Brazil has such a massive amount of hydropower that once wind and solar capacity gets built up the real question will be whether or not it will be worthwhile keeping any of the exisiting fossil fuel capacity operational to deal with dry years or just overbuild renewable capacity.

  • Bob_Wallace

    I don’t disagree that we will use fossil fuels as backup for a long time. The questions are “how much?” and “how long?”.

    Brazil is in the very early days of building a renewable grid. Where’s the solar in your numbers? Brazil is a sunny place.

    You’ve got some places that look good for tidal/run of river generation. How about geothermal? Wave? Biogas from urban sewage and waste?

    We might be using NG for deep backup 100 years from now. But as long as we keep the percentage low we, and the planet, can live with that.

  • Allan

    The US EIA estimates the offshore wind energy cost in US$ 204,00/MW in 2019. On shore costs is lower: US$ 80,00. The wind energy now is lower than gas in most countries, even in USA. The problem in wind power is the capacity factor: near 35%. A coal plant has 85%, near 2,5x more! The offshore increases this a little bit, but not to much. So, we need 2 to 3 times more installed power. A 1.000 KW coal plant is equivalent to a 2.500 KW wind farm. That is the problem with wind, sometimes it blows, sometimes not. Wind is one part of the answer.

    • Bob_Wallace

      Capacity factor is not as important metric as you might think. The important metric is the cost of the electricity produced. A secondary important metric is time of production. It wouldn’t matter if we had to install 20x more “nameplate” capacity wind to equal coal as long as the price of wind was cheaper.

      The wind blows a lot more than 35% of the time, especially offshore. Offshore wind also blows more during daytime hours when demand is higher. This makes it more valuable for places like the NE and northern Europe which have poorer winter solar resources.

      Wind is one part of the answer. Solar is another part. The other parts include hydro, geothermal, tidal, biomass/gas, possibly wave, and storage.

      Wind is the cheapest and produces more hours per day than solar, which might become the cheapest.

      • jburt56

        Thank you for responding to ‘wind don’t blow.’ I’m still recovering from carpal tunnel. . .(just joking) ;););)

    • jburt56

      You must be new to this blog.

    • JamesWimberley

      Current designs have higher capacity factors. 40% is not unusual for onshore now, This is done essentially by changing the ratio between rotor and generator size. Early designs assumed the object was maximum total output, newer ones trade peak output for duration. Full post by Zach here.

  • JamesWimberley

    “It also enables the WindFloat to employ standard onshore wind turbines,…” Really? Offshore turbines have to be ruggedized against salt corrosion. Maintenance visits are more expensive, so it’s worth spending money to minimize them. They also avoid the onshore size limit imposed by land transport of components, but it doesn’t look as if that concerns this project.

    Japan is also investing heavily in floating wind, for the same reason: on the Pacific side, there’s next to no continental shelf. The China Sea is shallower; but there is a dangerous tangle of competing state claims to islands and seabed, and most of the population is on the Pacific side.

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