The HuffPo has a post on a floating wind power pilot project in the US - First Floating Wind Turbine In The U.S. Deploys In Maine (from back in April - needless to say time is not of the essence here in recent years).

The first floating wind turbine in U.S. history went upright and onto the water in Brewer, Maine, on Friday, on its way to being put in place and connected to the grid off the coast near the town of Castine.

The 65-foot-tall VolturnUS 1:8 prototype is a small-scale model of the giant 6-megawatt turbines the University of Maine’s Advanced Structures and Composites Center and its partners in the DeepCWind Consortium hope to have in the water someday. Deep-water wind supporters in Maine believe that by 2030 they can grab 5 gigawatts of power with arrays of large turbines up to 50 miles off the coast, away from conflicts and where the winds blow strong and consistent. ...

Floating turbines are seen as a next logical step in offshore wind development. Standard offshore turbines are nearly always installed in waters less than 30 meters deep, but deeper water accessible only with floating turbines could offer even better wind as well as fewer stakeholder and aesthetic conflicts. A couple of demo floating projects have launched in Europe, one by Energias de Portugal and Principle Power off Portugal and the world’s first, in 2009, Statoil’s Hywind.

Beyond this smaller-scale pilot, DeepCWind is planning to build two of the 6-megawatt full-sized turbines in the 2015-17 period. To aid in that effort, this past December the U.S. Department of Energy gave the university a $4 million grant (at the same time it backed the Oregon floating project), and other such projects are brewing around the world.

Ultimately, the Maine group aims to have some 80 turbines floating in 4-mile by 8-mile zone 20 miles from the coast. The team figures those turbines will be able to produce electricity at 10 cents per kilowatt-hour without subsidies, meeting a 2020 goal of the DOE.

Renewable Energy World has an update on efforts to encourage larger wind turbines for offshore wind power (and floating offshore wind power) - Gigantic Offshore Wind-turbine Testing in Progress.

In the course of the next five years, the HiPRWind (High Power, High Reliability Offshore Wind Technology) project will lay the foundations for delivery of a complete, fully functional offshore wind-turbine with a generating capacity of 10 – 20 MW. For comparison, modern wind–turbine capacities lie between 300 kW and 6 MW. ...

Plenty of Power

As well as developing a concept for a 10 – 20 MW turbine, the members of the project are also looking at how the units of a huge floating wind-farm far out to sea can be interconnected, and connected to the electricity grid ashore.

The advantages of locating wind-turbines offshore are well known. A better wind regime is the first of these; it simply blows harder out at sea. Next, larger schemes can be built; a single North Sea block of 60 x 60 km is capable of producing more electricity than all Norway’s hydropower plants combined, while ten blocks could supply enough electric power for the whole of Europe.

The problem is: how to do it? Wind-turbines are already standing in shallow water off the UK and Denmark. But in the future, coastal sites are going to become more crowded, and both environmental and resource considerations will mean that these installations will have to be located further from the coast. ...

Wind Energy in Norway -- Updates

Three potential concepts for wind energy generation are currently under development in Norway: Hywind and Sway are based on turbines mounted on monotowers moored to the seabed, while Wind-Sea has three rotors mounted on a floater in the form of an equilateral triangle. Hywind has been in operation since 2009, while the other two are still at the model stage. Hywind is moored off Karmøy in southwestern Norway, but as it is owned by Statoil it cannot be used for tests by research institutes.

SINTEF has a high level of expertise in wind-power, including offshore, and some ten researchers at SINTEF Energy Research work full-time in this field. When the Research Council of Norway set up eleven centres of research on environmentally friendly energy, SINTEF Energy Research was allocated the management of the Nowitech and Cedren centres. Nowitech focuses on offshore wind technology, while Cedren’s contribution is to the development and dissemination of environmentally friendly designs.

As a result, Nowitech in Trondheim and Norcowe in Bergen were given funding last year to build a floating test turbine that will gather data and test a number of different designs. They will also build a floating station for measurements of wind and waves.

Technology Review has an article on the potential for vertical axis wind turbine designs to be used for floating offshore wind power - A New Twist on Floating Wind Power.

Wind turbines attached to floating buoys can harness stronger, more sustained winds in the open ocean. But the floats now used for such deep-water installations may prove prohibitively expensive because the buoys needed to keep them above water are enormous. Now a project in France is turning the turbine design on its head for what developers hope will be a low-cost alternative.

French oil and gas engineering company Technip and wind-power startup Nenuphar recently announced Vertiwind, a two-megawatt wind turbine that they plan to float in Mediterranean waters by the end of 2013. The project employs a turbine with a main rotor shaft that is set vertically, like a spinning top, rather than horizontally, as in a conventional wind turbine.

The benefit of the vertical-axis design is that it lowers the turbine's center of gravity. Vertiwind's design stands 100 meters tall, but places the generator, which weighs 50 tons, inside a sealed tube beneath the turbine's rotating blades, 20 meters above the sea. This makes the turbine less top-heavy, allowing for a significantly smaller flotation system, which would extend only nine meters below the surface of the ocean.

In contrast, a horizontal-axis turbine with the same power output and blades also reaching 100 meters high would need its generator to be 60 meters above the sea. A buoy built by Technip for a 2.3 megawatt horizontal-axis floating turbine prototype, owned by the Norwegian energy company Statoil, extends 100 meters below the surface.

"You save a lot of material" with a vertical axis, says Stephane His, vice president of biofuels and renewable energy at Technip. "But more than that, you ease the process of installing the machine itself."

Technip and Nenuphar plan to build two vertical-axis turbines with a power output of two megawatts each, one onshore and one offshore, at a cost of $28 million. The figure is still significantly more than shallow-water turbines fixed to the seafloor (which cost around $5 million per megawatt) but much less than the approximately $70 million spent on construction of the prototype owned by Statoil for construction, deployment, and ongoing research.
By pursuing a vertical-axis design, Vertiwind is using technology that was all but abandoned for onshore wind power more than a decade ago. Vertical-axis designs, which are inherently low to the ground, usually cannot compete with taller h

Irish Energy News reports that Portugal is getting in to the floating wind power game - First Offshore Floating Turbine in Portugal.

The first offshore floating wind turbine is now under construction off the coast of Aguçadoura in the north of Portugal. The project involves the construction of a 2MW wind turbine prototype over the next 6 months – one of the first of its kind in southern Europe. Installation and contruction costs are estimated to amount to 4.1 million Euros per MW installed.

The technology is patented by American company Power Principle using the name “WindFloat”. It consists of a triangular floating base. The base is allowed to float through the use of three pillars, one of which houses the tower structure for the wind turbine. The structure is anchored to the seabed through the use of cables and can be installed anywhere between depths of 50 meters to several hundred meters.

The design and size of the WindFloat enables the overall structure to be assembled onshore and towed to its final location. All fabrication and qualification is completed at quayside in a controlled environment. According to Principle Power, cost savings are significant when compared with direct/fixed offshore wind turbine support structures.

Cleandxr has a compilation of some Scandinavian floating wind power designs - Seven Innovative Floating Windmill Platform Concepts.

The Guardian has a report on floating offshore wind power developments in Scotland - Scotland bids to host world's first floating windfarm.

The Scottish government yesterday revealed it is in talks with Norwegian energy giant Statoil about hosting the world's first floating windfarm at two potential sites off the Scottish coast.

Statoil is currently testing a prototype version of its Hywind floating turbine 10km offshore at Karmøy in Norway and, after a successful wave of tests, is now assessing potential sites for a full-scale floating windfarm.

The company is planning to deploy between three and five floating wind turbines to demonstrate the commercial viability of the technology and senior executives at the firm met yesterday with Scottish First Minister Alex Salmond to discuss the viability of two prospective sites – one off the coast of Lewis and one off Aberdeenshire.

The talks are at a fairly advanced stage with Scottish Development International and Marine Scotland having already worked with Statoil to undertake feasibility studies at the proposed sites.

Speaking following the meeting in Norway, Salmond said that the talks had been "very positive", adding that the project had the potential to revolutionise the offshore energy industry.

"The Hywind II windfarm project would see a Scotland-Norway collaboration push the boundaries of deepwater offshore wind beyond the 100m mark and open up vast areas of the world's oceans to the development of wind energy for the first time," he said.

The New York Times has a post on StatoilHydro and Siemens finally installing the world's first large-scale floating offshore wind turbine off the coast of Karmøy, Norway. The 2.3 MW Hywind was built at a depth of 722 feet and will be tested over the next two years - Wind Farming in Deep Waters.

Most existing offshore wind turbines are mounted firmly to the seabed.

Now StatoilHydro of Norway and Siemens of Germany are installing what they say is the world’s first large-scale floating turbine to exploit the potential of the technology in deep waters.

Building foundations to attach turbines to the seabed becomes expensive at water depths of more than about 50 meters (164 feet), according to the companies. That has limited large-scale exploitation of offshore wind power, particularly in countries with little or no shallow water near the coast line, they said.

Expansion near coastlines can also be difficult because of restrictions on construction in fishing grounds and bird migration zones. And an advantage of building on the high seas is that winds are stronger and more consistent than near the coast.

Another advantage may be that deep-water installations are more acceptable to shoreline residents, who say that turbines in shallower waters blight their views.

The new turbine is designed to be suitable for installation in water depths between 120 and 700 meters (394-2,297 feet), allowing them to be “placed much more freely than before,” said Henrik Stiesdal of the wind power unit at Siemens. ...

Siemens is supplying the turbine, which will start delivering electricity in mid-July. StatoilHydro is providing the floating structure with a center of gravity deep below the water surface to reduce bobbing. That structure would then be fastened to the seabed by three anchor wires.

Even so, the companies have developed an “advanced control system” to take “advantage of the turbine’s ability to dampen out part of the wave-induced motions of the floating system.”

The Green Wombat has a report on a new floating offshore wind power plant planned for Portugal - Portugal floats offshore wind farm plan.

Portugal has become a prime spot for wave energy farms, given the coastal conditions and the government’s support for renewable energy projects. Now Portuguese energy powerhouse Energias de Portugal has signed an agreement with Seattle’s Principle Power for a deep-water floating wind farm.

It’s the second floating wind farm for Principle Power, which last October inked a contract to construct a 150-megawatt turbine power plant off the Oregon coast. The Oregon plan calls for 30 floating platforms that will each sport a five-megawatt wind turbine - which is about twice the size of the biggest land-based turbines in commercial operation. (General Electric (GE) makes a 3.6-megawatt turbine designed for offshore and Clipper Windpower is developing a ten-megawatt prototype.)

Details of the deal with Portugal’s EDP, however, are next to non-existent. Principle Power president Jon Bonanno told Green Wombat that the size of the Portuguese wind farm, the type of turbine it will use, its cost and build date are confidential. “What I can say is that the phased build out will result in a utility scale project, within a reasonable time frame for a plant of its size and nature,” Bonanno wrote in an e-mail.

Matthew Simmons has received quite a bit of press in the past week, after his Ocean Energy Institute floated a proposal to build a $25 billion, 5 GW wind farm in the Gulf of Maine.

Offshore wind farms have a number of advantages over their land based equivalents - they are less hazardous to wildlife, have fewer objections raised on NIMBY concerns and winds are generally stronger over the oceans than they are over land.

Ideally, offshore wind farms will be far enough away from land to avoid being seen from the shoreline, eliminating any residual objections from local residents. Current offshore projects tend to site turbines in waters less than 20 metres deep - going further offshore would mean locating them at depths of 50 meters or more, which is too deep to build supporting towers or trusses down to the sea floor at an affordable cost.

A solution to this problem is floating platforms - one of the key elements of the Ocean Energy Institute proposal. In this post I'll look at some of the work being done to develop floating offshore wind power platforms in order to enable these sorts of schemes to become a reality.

Floating Wind Turbines

According to a 2006 report by the U.S. Department of Energy, General Electric and the Massachusetts Technology Collaborative, offshore wind resources on the Atlantic and Pacific coasts of the United States exceed the current electricity generation of the entire U.S. power industry. NASA has also been investigating ocean wind strengths worldwide, using the QuikSCAT satellite.

Researchers at MIT and elsewhere have been investigating the feasibility of "tension-leg" platforms for wind turbines, a technology that oil companies have been using for deep-water rigs. The structures would be assembled at a shipyard and placed on large floating cylinders that are ballasted with high-density concrete (to keep the structure from tipping over) and then tugged out to sea. Once in location, steel cables would be attached to the platform, anchoring it to the sea floor.

The MIT researchers claim that large turbines located far offshore could eventually generate cheaper power than both land based wind farms and near-offshore ones (even taking into account the increased cost of longer underground electricity transmission cables). Part of the cost advantage is the higher capacity factor achieved due to more consistent offshore winds - potentially averaging between 40 percent and 50 percent compared with 30 percent or less with land based turbines.

Some offshore wind farms could also have advantages in terms of proximity to large coastal cities compared to wind farms in remote areas, which require grid transmission upgrades to transport the power to places where it is consumed. Floating offshore wind farms also avoid bottlenecks in the supply of marine construction equipment such as pile drivers and cranes that may hamper rapid expansion of shallow offshore wind structures (however they may instead compete for some resources with offshore oil exploration and production, which could be problematical in the short to medium term).

A number of companies are active in the area of floating offshore wind technology - primarily Blue H Technologies, StatOil Hydro and SWAY.

Blue H Technologies

Blue H Technologies is a Dutch company that launched their first test platform at Tricase off Italy's southern coast late last year. The company has also announced plans to install another test turbine off Massachusetts.

The Blue H test platform in Italy is a tension-leg platform - a conventional offshore oil and gas platform design that floats below the surface, held in place by chains running to steel or concrete anchors on the seabed. The platform is located 10 km offshore and hosts an 80-kilowatt wind turbine which is mounted with sensors to record the wave and wind forces experienced by the equipment.

Blue H is now constructing a commercial wind farm for the Tricase site, which will have an installed capacity of 92 MW.

Blue H's design is unusual in that the turbine has a two-bladed rotor rather than the conventional three-blade design used elsewhere in. Technology Review has quoted Martin Jakubowski, Blue H cofounder and chief technology officer, as saying that "the noise and jarringly high rotation speeds that made two-bladers a loser on land are either irrelevant or a plus offshore" and that the fast rotation is "less susceptible to interference from the back-and-forth swing of the platform under wave action" and means less torque, resulting in a lighter structure (Blue H's 2.5-megawatt turbine will weigh 97 tons - 53 tons lighter than the lightest machine of the same power output on the market).

Tech Review also quotes Jakubowski as estimating that Blue H's wind farms will "deliver wind energy for seven to eight cents per kilowatt-hour, roughly matching the current cost of natural gas-fired generation and conventional onshore wind energy".



StatOil Hydro

Norwegian oil and gas producer StatoilHydro and Germany's Siemens (a major wind-turbine producer) are partnering in a project to build a commercial-scale floating wind farm about 10 kilometers offshore from Karmøy on Norway's southwestern tip.

StatoilHydro initially plans to operate a 2.3 MW wind turbine atop a conventional oil and gas platform, and is hoping for this to be operational in late 2009. Unlike the Blue H design, StatOilHydro is using traditional wind turbines.

The company believes floating wind farms are the way of the future, with a company spokesman saying that there are a declining number of sites available onshore and in shallow waters and citing regions without a shallow continental shelf like California, Japan and Norway where traditional offshore wind is not possible.

StatOilHydro says that deepwater wind power will be expensive in the initial stages but that the economics could eventually rival those of conventional wind power.

If deep offshore wind power in the North Sea proves to be successful it would become a major component on the planned European Supergrid, which backers hope will link up the region's power networks and allow a much higher proportion of renewable energy in future (possibly entirely fossil-free, as it will need to become eventually).



SWAY

SWAY, based in Bergen, Norway, plans to field a prototype of its floating wind turbine in 2010. SWAY's platform is basically a spar buoy that can rise and fall gently with wave action, requiring less anchoring than the tension-leg platform. The buoy, mounted on a column nearly 200 meters tall, is held in place by a 2,400-ton gravel ballast. A three-bladed turbine is used, but, unlike conventional onshore turbines, it faces downwind rather upwind to better accommodate heeling of the tower, which may make it more effective in rougher waters than alternative designs.

The Simmons Plan

The cost estimated for Simmons' plan is $5 billion per gigawatt — more than double the amount that T. Boone Pickens’ now delayed wind farm in Texas is supposed to cost.

This seems high if the cost savings expected by the companies mentioned above eventuate, with the StatOilHydro experiment probably being the best guide, with the North Sea facing similar weather challenges to those experienced off New England.

Winter winds in the Gulf of Maine carry as much as eight times more energy as summer breezes, meaning maximum power is available during periods of greatest demand. About 80 percent of Maine residents use oil to heat their homes. The average family uses about 1,000 gallons, or 3,785 liters a year - when prices are around $4 a gallon ($1 a litre) this consumes about one-tenth of the average family's annual income, leading Simmons to declare "If we don't do this, we're [eventually] going to have to evacuate most of Maine".

Seen in that light, even an expensive offshore wind farm is better than the alternative.

As an added bonus, construction and maintenance of the structures will bring valuable job opportunities to a region hard hit by the decline of the fishing industry.

Related Posts :

The Oil Drum - Alternative Wind Power Experiments - SkySails and Airborne Wind Turbines (Peak Energy)

The Oil Drum - Offshore Wind

Cross-posted from Our Clean Energy Future.