Floating wind turbine
Encyclopedia
A floating wind turbine is an offshore wind turbine
mounted on a floating structure that allows the turbine to generate electricity
in water depths where bottom-mounted towers are not feasible. The wind
can be stronger and steadier over water due to the absence of topographic features that may disrupt wind flow.
The relocation of wind farms into the sea can reduce visual pollution
if the windmills are sited more than 12 miles (19.3 km) offshore, provide better accommodation of fishing and shipping lanes, and allow silting near heavily developed coastal cities.
Floating wind parks are wind farms that site several floating wind turbines closely together to take advantage of common infrastructure such as power transmission facilities.
in 1972. [I]t was not until the mid 1990s, after the commercial wind industry
was well established, that the topic was taken up again by the mainstream research community." As of 2003, existing offshore fixed-bottom wind turbine technology deployments had been limited to water depths of 30 metres. Worldwide deep-water wind resources are extremely abundant in subsea
areas with depths up to 600 metres, which are thought to best facilitate transmission
of the generated electric power
to shore communities.
.
Blue H deployed the first 80 kW floating wind turbine 113 kilometres (70.2 mi) off the coast of Italy in December, 2007. It was then decommissioned at the end of 2008 after completing a planned test year of gathering operational data.
SeaTwirl
deployed their first floating grid connected wind turbine off the coast of Sweden in August, 2011. There new design is storing energy as a flywheel and by transporting water it can be charged and uncharged even after the wind has stopped blowing.
The first large-capacity, 2.3 megawatt floating wind turbine is Hywind, which became operational in the North Sea
off of Norway
in September 2009,
and is still operational .
operated the first floating wind turbine,
a prototype deep-water platform with an 80-kilowatt turbine off Puglia, southeast Italy
in 2008. Installed 21 km off the coast in waters 113 metres deep in order to gather test data on wind and sea conditions, the small prototype unit was decommissioned at the end of 2008. Blue H has plans to build a 38-unit deepwater wind farm at the same location.
The Blue H technology utilized a tension-leg platform
design and a two-bladed turbine. The two-bladed design can have a "much larger chord
, which allows a higher tip speed than those of three-bladers. The resulting increased background noise
of the two-blade rotor is not a limiting factor for offshore sites."
, Blue H was building a full-scale commercial 2.4 MWe unit in Brindisi, Italy which it expected to deploy at the same site of the prototype in the southern Adriatic Sea
in 2010. This is the first unit in the planned 90 MW Tricase offshore wind farm, located more than 20 km off the Puglia coast line.
off Norway
.
The Hywind was towed out to sea in early June 2009. The 2.3 megawatt turbine was constructed by Siemens Wind Power
and mounted on a floating tower with a 100 metre deep draft. The float tower was constructed by Technip
.
Statoil
says that floating wind turbines are still immature and commercialization is distant.
The installation is owned by Statoil
and will be tested for two years. After assembly in the calmer waters of Åmøy Fjord near Stavanger, Norway
, the 120-meter-tall tower with a 2.3 MW turbine was towed 10 km offshore into 220-metre-deep water, 10 km southwest of Karmøy
, on 6 June 2009 for a two year test deployment." Alexandra Beck Gjorv of Statoil said, "[The experiment] should help move offshore wind farms out of sight ... The global market for such turbines is potentially enormous, depending on how low we can press costs." The unit became operational in the summer of 2009.
Hywind was inaugurated on 8 September 2009.
, after a full year of operation, the Hywind turbine is still operating and generating electricity for the Norwegian grid, and still is as of February 2011.
The turbine cost 400 million kroner (around US$62 million) to build and deploy. The 13 kilometres (8.1 mi) long submarine power transmission cable
was installed in July, 2009 and system test including rotor blades and initial power transmission was conducted shortly thereafter. The installation is expected to generate about 9 GW·h of electricity annually.
The SWATH (Small Waterplane Area Twin Hull), a new class of offshore wind turbine service boat, will be tested at Hywind.
Hywind delivered 7.3 GWh in 2010, and survived 11 meter waves with seemingly no wear.
, additional pilot Hywind installations are planned in the US and in the North Sea
off the coast of Scotland
.
and catenary
loose mooring systems.
Tension leg mooring systems have vertical tethers under tension providing large restoring moments
in pitch and roll
. Catenary mooring systems provide station keeping for an offshore structure yet provide little stiffness at low tensions." A third form of mooring system is the ballasted catenary configuration, created by adding multiple-tonne weights hanging from the midsection of each anchor cable in order to provide additional cable tension and therefore increase stiffness of the above-water floating structure.
and close proximity to large load centres (e.g. shorter transmission runs)."
however, the economic feasibility of shallow-water offshore wind technologies is more completely understood. With empirical data obtained from fixed-bottom installations off many countries for over a decade now, representative costs are well understood. Shallow-water turbines cost between 2.4 and 3 million United States dollar
s per megawatt to install, according to the World Energy Council
.
, the practical feasibility and per-unit economics of deep-water, floating-turbine offshore wind is yet to be seen. Initial deployment of single full-capacity turbines in deep-water locations began only in 2009.
, new feasibility studies are supporting that floating turbines are becoming both technically and economically viable in the UK and global energy markets. "The higher up-front costs associated with developing floating wind turbines would be offset by the fact that they would be able to access areas of deep water off the coastlne of the UK where winds are stronger and reliable."
The recent Offshore Valuation study conducted in the UK has confirmed that using just one third of the UK's wind, wave and tidal resource could generate energy equivalent to 1 billion barrels of oil per year; the same as North Sea oil and gas production. Some of the primary challenges are the coordination needed to develop transmission lines.
While the floater concept and patents are not yet publicly disclosed, the company is communicating on its web site mobility solution to reduce wake losses in an offshore wind farm by repositioning the floating turbines depending on the wind direction.
The company has patented a mechanical solution to move the floater along its mooring lines and has developed a software to optimize in real-time the farm layout. Eliminating wake losses allows to increase significantly the power production as well as to reduce the long-term components failures.
According to publicly released information, Ideol has a construction and installation cost of around 1M Euro per MW. As such, the company intends to offer an alternative to fixed foundations starting from 40 m water depth.
OffshoreWind.biz reported that the company will build a 5 MW floating prototype off the European coast in 2013.
s designed and patented by Principle Power. It is to be tested in autumn 2011 off the coast of Portugal
with a Vestas
V80 2MW wind turbine.
The foundation attempts to improve dynamic stability at shallow draft
by dampening wave and turbine induced motion utilizing a tri-column triangular platform with the wind turbine positioned on only one of the three columns. The triangular platform is then "moored with 4 lines, 2 of which are connected to the column stabilizing the turbine, thus creating an asymmetric" mooring to increase stability and reduce motion.
As the wind shifts direction and changes the loads on the turbine and foundation, pumps will shift ballast water between foundation chambers.
The project is managed by the joint venture
WindPlus (led by electricity provider Energias de Portugal
).
Vestas turbines will be the standard for the project.
Construction cost is expected to be below $30 million, and funded by the project partners and Fundo de Apoio à Inovação.
This technology could allow wind turbines to be sited in offshore areas that were previously considered inaccessible, areas having water depth exceeding 50 metres and more powerful wind resources than shallow-water offshore wind farms typically encounter.
(IEA), under the auspices of their Offshore Code Comparison Collaboration (OC3) initiative, has completed high-level design and simulation modeling of the OC-3 Hywind system, a 5-MW wind turbine installed on a floating spar buoy
, moored with catenary mooring lines, in water depth of 320 metres. The spar buoy platform would extend 120 meters below the surface and the mass of such a system, including ballast
would exceed 7.4 million kg.
and 11 international partners started a 4-year program called DeepWind in October 2010 to create and test economical floating Vertical Axis Wind Turbine
s up to 20MW. The program is supported with €
3m through EUs Seventh Framework Programme.
Partners include TUDelft
, SINTEF
, Statoil
and United States
National Renewable Energy Laboratory
.
design created by Nenuphar http://www.nenuphar-wind.com/ and currently being tested by Technip http://www.technip.com/. See http://www.nenuphar-wind.com/press
of northeast Japan
where the recent disaster
has created a scarcity of electric power. After the evaluation phase is complete in 2016, "Japan plans to build as many as 80 floating wind turbines off Fukushima by 2020."
The cost is expected to be in the range of 10-20 billion Yen over five years to build the first six floating wind turbines.
Some foreign companies also plan to bid on the large floating wind farm that Japan hopes to build by 2020.
, Statoil plans to build a multi-turbine project in Scottish
waters utilizing the Hywind design.
The US State of Maine
solicited proposals in September 2010 to build the world's first floating, commercial wind farm. The RFP is seeking proposals for 25 MW of deep-water offshore wind capacity to supply power for 20-year long-term contract period via grid-connected floating wind turbines in the Gulf of Maine
. Successful bidders must enter into long-term power supply contracts with either Central Maine Power Company (CMP), Bangor Hydro-Electric Company
(BHE), or Maine Public Service Company (MPS). Proposals were due by May 2011.
Some vendors who could bid on the proposed project have expressed concerns about dealing with the United States
regulatory environment. Since the proposed site is in Federal waters
, developers would need a permit from the Minerals Management Service
, "which took more than seven years to approve a yet-to-be-built, shallow-water wind project
off Cape Cod
," and is also the agency under fire in June 2010 for lax oversight of deepwater oil drilling in Federal waters.
"Uncertainty over regulatory hurdles in the United States ... is 'the Achilles heel' for Maine's ambitions for deepwater wind."
Wind turbine
A wind turbine is a device that converts kinetic energy from the wind into mechanical energy. If the mechanical energy is used to produce electricity, the device may be called a wind generator or wind charger. If the mechanical energy is used to drive machinery, such as for grinding grain or...
mounted on a floating structure that allows the turbine to generate electricity
Electricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...
in water depths where bottom-mounted towers are not feasible. The wind
Wind
Wind is the flow of gases on a large scale. On Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space...
can be stronger and steadier over water due to the absence of topographic features that may disrupt wind flow.
The relocation of wind farms into the sea can reduce visual pollution
Visual pollution
Visual pollution is the term given to unattractive and man-made visual elements of a vista, a landscape, or any other thing that a person does not feel comfortable to look at. Visual pollution is an aesthetic issue, referring to the impacts of pollution that impair one's ability to enjoy a vista or...
if the windmills are sited more than 12 miles (19.3 km) offshore, provide better accommodation of fishing and shipping lanes, and allow silting near heavily developed coastal cities.
Floating wind parks are wind farms that site several floating wind turbines closely together to take advantage of common infrastructure such as power transmission facilities.
History
The concept for "large-scale offshore floating wind turbines was introduced by Professor William E. Heronemus at the University of MassachusettsUniversity of Massachusetts
This article relates to the statewide university system. For the flagship campus often referred to as "UMass", see University of Massachusetts Amherst...
in 1972. [I]t was not until the mid 1990s, after the commercial wind industry
Wind power
Wind power is the conversion of wind energy into a useful form of energy, such as using wind turbines to make electricity, windmills for mechanical power, windpumps for water pumping or drainage, or sails to propel ships....
was well established, that the topic was taken up again by the mainstream research community." As of 2003, existing offshore fixed-bottom wind turbine technology deployments had been limited to water depths of 30 metres. Worldwide deep-water wind resources are extremely abundant in subsea
Subsea
Subsea is a general term frequently used to refer to equipment, technology, and methods employed in marine biology, undersea geology, offshore oil and gas developments, underwater mining, and offshore wind power industries.- Oil and gas :...
areas with depths up to 600 metres, which are thought to best facilitate transmission
Electric power transmission
Electric-power transmission is the bulk transfer of electrical energy, from generating power plants to Electrical substations located near demand centers...
of the generated electric power
Submarine power cable
Submarine power cables are major transmission cables for carrying electric power below the surface of the water. These are called "submarine" because they usually carry electric power beneath salt water but it is also possible to use submarine power cables beneath fresh water...
to shore communities.
Operational deep-water platforms
, there have been only three operational floating wind turbines used to farm wind energyWind energy
Wind energy is the kinetic energy of air in motion; see also wind power.Total wind energy flowing through an imaginary area A during the time t is:E = ½ m v2 = ½ v 2...
.
Blue H deployed the first 80 kW floating wind turbine 113 kilometres (70.2 mi) off the coast of Italy in December, 2007. It was then decommissioned at the end of 2008 after completing a planned test year of gathering operational data.
SeaTwirl
SeaTwirl
Sea Twirl is a vertical floating wind turbine currently being tested off the west coast of Sweden. The design enables the use of cheaper, heavier materials and continuing generation of power when the wind is low....
deployed their first floating grid connected wind turbine off the coast of Sweden in August, 2011. There new design is storing energy as a flywheel and by transporting water it can be charged and uncharged even after the wind has stopped blowing.
The first large-capacity, 2.3 megawatt floating wind turbine is Hywind, which became operational in the North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...
off of Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
in September 2009,
and is still operational .
Blue H Technologies
Blue H Technologies of the NetherlandsNetherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
operated the first floating wind turbine,
a prototype deep-water platform with an 80-kilowatt turbine off Puglia, southeast Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
in 2008. Installed 21 km off the coast in waters 113 metres deep in order to gather test data on wind and sea conditions, the small prototype unit was decommissioned at the end of 2008. Blue H has plans to build a 38-unit deepwater wind farm at the same location.
The Blue H technology utilized a tension-leg platform
Tension-leg platform
A Tension-leg platform or Extended Tension Leg Platform is a vertically moored floating structure normally used for the offshore production of oil or gas, and is particularly suited for water depths greater than 300 metres and less than 1500 meters...
design and a two-bladed turbine. The two-bladed design can have a "much larger chord
Chord (aircraft)
In aeronautics, chord refers to the imaginary straight line joining the trailing edge and the center of curvature of the leading edge of the cross-section of an airfoil...
, which allows a higher tip speed than those of three-bladers. The resulting increased background noise
Noise pollution
Noise pollution is excessive, displeasing human, animal or machine-created environmental noise that disrupts the activity or balance of human or animal life...
of the two-blade rotor is not a limiting factor for offshore sites."
, Blue H was building a full-scale commercial 2.4 MWe unit in Brindisi, Italy which it expected to deploy at the same site of the prototype in the southern Adriatic Sea
Adriatic Sea
The Adriatic Sea is a body of water separating the Italian Peninsula from the Balkan peninsula, and the system of the Apennine Mountains from that of the Dinaric Alps and adjacent ranges...
in 2010. This is the first unit in the planned 90 MW Tricase offshore wind farm, located more than 20 km off the Puglia coast line.
Hywind
The world's first operational deep-water floating large-capacity wind turbine is the Hywind, in the North SeaNorth Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...
off Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
.
The Hywind was towed out to sea in early June 2009. The 2.3 megawatt turbine was constructed by Siemens Wind Power
Siemens Wind Power
Siemens Wind Power, or SWP, is a wind turbine manufacturer with headquarters and main production facilities established in 1980 in Brande, Denmark. SWP is wholly owned by Siemens of Germany since 2004 through the Renewable Energy division in the Siemens Energy sector...
and mounted on a floating tower with a 100 metre deep draft. The float tower was constructed by Technip
Technip
Technip is a provider of project management, engineering, and construction services for the oil and gas industry, headquartered in Paris, France....
.
Statoil
Statoil
Statoil ASA is a Norwegian petroleum company established in 1972. It merged with Norsk Hydro in 2007 and was known as StatoilHydro until 2009, when the name was changed back to Statoil ASA. The brand Statoil was retained as a chain of fuel stations owned by StatoilHydro...
says that floating wind turbines are still immature and commercialization is distant.
The installation is owned by Statoil
Statoil
Statoil ASA is a Norwegian petroleum company established in 1972. It merged with Norsk Hydro in 2007 and was known as StatoilHydro until 2009, when the name was changed back to Statoil ASA. The brand Statoil was retained as a chain of fuel stations owned by StatoilHydro...
and will be tested for two years. After assembly in the calmer waters of Åmøy Fjord near Stavanger, Norway
Stavanger
Stavanger is a city and municipality in the county of Rogaland, Norway.Stavanger municipality has a population of 126,469. There are 197,852 people living in the Stavanger conurbation, making Stavanger the fourth largest city, but the third largest urban area, in Norway...
, the 120-meter-tall tower with a 2.3 MW turbine was towed 10 km offshore into 220-metre-deep water, 10 km southwest of Karmøy
Karmøy
Karmøy is a municipality in Rogaland county, Norway. It is located southwest of the city of Haugesund in the traditional district of Haugaland....
, on 6 June 2009 for a two year test deployment." Alexandra Beck Gjorv of Statoil said, "[The experiment] should help move offshore wind farms out of sight ... The global market for such turbines is potentially enormous, depending on how low we can press costs." The unit became operational in the summer of 2009.
Hywind was inaugurated on 8 September 2009.
, after a full year of operation, the Hywind turbine is still operating and generating electricity for the Norwegian grid, and still is as of February 2011.
The turbine cost 400 million kroner (around US$62 million) to build and deploy. The 13 kilometres (8.1 mi) long submarine power transmission cable
Submarine power cable
Submarine power cables are major transmission cables for carrying electric power below the surface of the water. These are called "submarine" because they usually carry electric power beneath salt water but it is also possible to use submarine power cables beneath fresh water...
was installed in July, 2009 and system test including rotor blades and initial power transmission was conducted shortly thereafter. The installation is expected to generate about 9 GW·h of electricity annually.
The SWATH (Small Waterplane Area Twin Hull), a new class of offshore wind turbine service boat, will be tested at Hywind.
Hywind delivered 7.3 GWh in 2010, and survived 11 meter waves with seemingly no wear.
, additional pilot Hywind installations are planned in the US and in the North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...
off the coast of Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
.
Topologies
Platform topologies can be classified into:- single-turbine-floater (one wind turbine mounted on a floating structure)
- multiple turbine floaters (multiple wind turbines mounted on a floating structure)
Engineering considerations
Undersea mooring of floating wind turbines are accomplished with three principal mooring systems. Two common types of engineered design for anchoring floating structures include tension-legTension-leg platform
A Tension-leg platform or Extended Tension Leg Platform is a vertically moored floating structure normally used for the offshore production of oil or gas, and is particularly suited for water depths greater than 300 metres and less than 1500 meters...
and catenary
Catenary
In physics and geometry, the catenary is the curve that an idealised hanging chain or cable assumes when supported at its ends and acted on only by its own weight. The curve is the graph of the hyperbolic cosine function, and has a U-like shape, superficially similar in appearance to a parabola...
loose mooring systems.
Tension leg mooring systems have vertical tethers under tension providing large restoring moments
Moment of inertia
In classical mechanics, moment of inertia, also called mass moment of inertia, rotational inertia, polar moment of inertia of mass, or the angular mass, is a measure of an object's resistance to changes to its rotation. It is the inertia of a rotating body with respect to its rotation...
in pitch and roll
Flight dynamics
Flight dynamics is the science of air vehicle orientation and control in three dimensions. The three critical flight dynamics parameters are the angles of rotation in three dimensions about the vehicle's center of mass, known as pitch, roll and yaw .Aerospace engineers develop control systems for...
. Catenary mooring systems provide station keeping for an offshore structure yet provide little stiffness at low tensions." A third form of mooring system is the ballasted catenary configuration, created by adding multiple-tonne weights hanging from the midsection of each anchor cable in order to provide additional cable tension and therefore increase stiffness of the above-water floating structure.
Economics
"Technically, the [theoretical] feasibility of deepwater [floating] wind turbines is not questioned as long-term survivability of floating structures has already been successfully demonstrated by the marine and offshore oil industries over many decades. However, the economics that allowed the deployment of thousands of offshore oil rigs have yet to be demonstrated for floating wind turbine platforms. For deepwater wind turbines, a floating structure will replace pile-driven monopoles or conventional concrete bases that are commonly used as foundations for shallow water and land-based turbines. The floating structure must provide enough buoyancy to support the weight of the turbine and to restrain pitch, roll and heave motions within acceptable limits. The capital costs for the wind turbine itself will not be significantly higher than current marinized turbine costs in shallow water. Therefore, the economics of deepwater wind turbines will be determined primarily by the additional costs of the floating structure and power distribution system, which are offset by higher offshore windsWind resource assessment
Wind resource assessment is the process by which wind power developers estimate the future energy production of a wind farm. Accurate wind resource assessments are crucial to the successful development of wind farms.- History :...
and close proximity to large load centres (e.g. shorter transmission runs)."
however, the economic feasibility of shallow-water offshore wind technologies is more completely understood. With empirical data obtained from fixed-bottom installations off many countries for over a decade now, representative costs are well understood. Shallow-water turbines cost between 2.4 and 3 million United States dollar
United States dollar
The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....
s per megawatt to install, according to the World Energy Council
World Energy Council
The World Energy Council is a global and inclusive forum for thought-leadership and tangible engagement with headquarters in London. Its mission is 'To promote the sustainable supply and use of energy for the greatest benefit of all people'....
.
, the practical feasibility and per-unit economics of deep-water, floating-turbine offshore wind is yet to be seen. Initial deployment of single full-capacity turbines in deep-water locations began only in 2009.
, new feasibility studies are supporting that floating turbines are becoming both technically and economically viable in the UK and global energy markets. "The higher up-front costs associated with developing floating wind turbines would be offset by the fact that they would be able to access areas of deep water off the coastlne of the UK where winds are stronger and reliable."
The recent Offshore Valuation study conducted in the UK has confirmed that using just one third of the UK's wind, wave and tidal resource could generate energy equivalent to 1 billion barrels of oil per year; the same as North Sea oil and gas production. Some of the primary challenges are the coordination needed to develop transmission lines.
Floating design concepts
Ideol
Ideol is a French company that has patented a new floating platform concept specifically designed for offshore wind.While the floater concept and patents are not yet publicly disclosed, the company is communicating on its web site mobility solution to reduce wake losses in an offshore wind farm by repositioning the floating turbines depending on the wind direction.
The company has patented a mechanical solution to move the floater along its mooring lines and has developed a software to optimize in real-time the farm layout. Eliminating wake losses allows to increase significantly the power production as well as to reduce the long-term components failures.
According to publicly released information, Ideol has a construction and installation cost of around 1M Euro per MW. As such, the company intends to offer an alternative to fixed foundations starting from 40 m water depth.
OffshoreWind.biz reported that the company will build a 5 MW floating prototype off the European coast in 2013.
WindFloat
WindFloat is a floating foundation for offshore wind turbineWind turbine
A wind turbine is a device that converts kinetic energy from the wind into mechanical energy. If the mechanical energy is used to produce electricity, the device may be called a wind generator or wind charger. If the mechanical energy is used to drive machinery, such as for grinding grain or...
s designed and patented by Principle Power. It is to be tested in autumn 2011 off the coast of Portugal
Portugal
Portugal , officially the Portuguese Republic is a country situated in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of Europe, and is bordered by the Atlantic Ocean to the West and South and by Spain to the North and East. The Atlantic archipelagos of the...
with a Vestas
Vestas
Vestas Wind Systems A/S is a Danish manufacturer, seller, installer, and servicer of wind turbines. It is the largest in the world, but due to very rapid growth of its competitors, its market share decreased from 28% in 2007 to 12.5% in 2009...
V80 2MW wind turbine.
The foundation attempts to improve dynamic stability at shallow draft
Draft (hull)
The draft of a ship's hull is the vertical distance between the waterline and the bottom of the hull , with the thickness of the hull included; in the case of not being included the draft outline would be obtained...
by dampening wave and turbine induced motion utilizing a tri-column triangular platform with the wind turbine positioned on only one of the three columns. The triangular platform is then "moored with 4 lines, 2 of which are connected to the column stabilizing the turbine, thus creating an asymmetric" mooring to increase stability and reduce motion.
As the wind shifts direction and changes the loads on the turbine and foundation, pumps will shift ballast water between foundation chambers.
The project is managed by the joint venture
Joint venture
A joint venture is a business agreement in which parties agree to develop, for a finite time, a new entity and new assets by contributing equity. They exercise control over the enterprise and consequently share revenues, expenses and assets...
WindPlus (led by electricity provider Energias de Portugal
Energias de Portugal
EDP - Energias de Portugal ranks among Europe's major electricity operators, as well as being one of Portugal's largest business groups....
).
Vestas turbines will be the standard for the project.
Construction cost is expected to be below $30 million, and funded by the project partners and Fundo de Apoio à Inovação.
This technology could allow wind turbines to be sited in offshore areas that were previously considered inaccessible, areas having water depth exceeding 50 metres and more powerful wind resources than shallow-water offshore wind farms typically encounter.
Nautica Windpower
Nautica Windpower uses a patented technology aimed at reducing system weight, complexity and costs for deep water sites. Scale model tests in open water have been conducted and structural dynamics modeling is under development for a multi-megawatt design. Nautica Windpower's Advanced Floating Turbine (AFT) uses a single mooring line and a downwind two-bladed rotor configuration that is deflection tolerant and aligns itself with the wind without an active yaw system. Two-bladed, downwind turbine designs that can accommodate flexibility in the blades will potentially prolong blade lifetime, diminish structural system loads and reduce offshore maintenance needs, yielding lower lifecycle costs.OC3-Hywind
The International Energy AgencyInternational Energy Agency
The International Energy Agency is a Paris-based autonomous intergovernmental organization established in the framework of the Organisation for Economic Co-operation and Development in 1974 in the wake of the 1973 oil crisis...
(IEA), under the auspices of their Offshore Code Comparison Collaboration (OC3) initiative, has completed high-level design and simulation modeling of the OC-3 Hywind system, a 5-MW wind turbine installed on a floating spar buoy
Spar buoy
A spar buoy is a tall, thin buoy that floats upright in the water and is characterized by a small water plane area and a large mass. Because they tend to be stable ocean platforms, spar buoys are popular for making oceanographic measurements. Adjustment of the water plane area and the mass allows...
, moored with catenary mooring lines, in water depth of 320 metres. The spar buoy platform would extend 120 meters below the surface and the mass of such a system, including ballast
Sailing ballast
Ballast is used in sailboats to provide moment to resist the lateral forces on the sail. Insufficiently ballasted boats will tend to tip, or heel, excessively in high winds. Too much heel may result in the boat capsizing. If a sailing vessel should need to voyage without cargo then ballast of...
would exceed 7.4 million kg.
DeepWind
RisøRisø DTU National Laboratory for Sustainable Energy
Risø DTU National Laboratory for Sustainable Energy is a scientific research organization north of Roskilde, Denmark. From 1 January 2008 it was made an institute under Technical University of Denmark...
and 11 international partners started a 4-year program called DeepWind in October 2010 to create and test economical floating Vertical Axis Wind Turbine
Vertical axis wind turbine
Vertical-axis wind turbines are a type of wind turbine where the main rotor shaft is set vertically and the main components are located at the base of the turbine...
s up to 20MW. The program is supported with €
Euro
The euro is the official currency of the eurozone: 17 of the 27 member states of the European Union. It is also the currency used by the Institutions of the European Union. The eurozone consists of Austria, Belgium, Cyprus, Estonia, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg,...
3m through EUs Seventh Framework Programme.
Partners include TUDelft
Delft University of Technology
Delft University of Technology , also known as TU Delft, is the largest and oldest Dutch public technical university, located in Delft, Netherlands...
, SINTEF
SINTEF
SINTEF , headquartered in Trondheim, Norway, is the largest independent research organisation in Scandinavia. Every year, SINTEF supports research and development at 2,000 or so Norwegian and overseas companies via its research and development activity....
, Statoil
Statoil
Statoil ASA is a Norwegian petroleum company established in 1972. It merged with Norsk Hydro in 2007 and was known as StatoilHydro until 2009, when the name was changed back to Statoil ASA. The brand Statoil was retained as a chain of fuel stations owned by StatoilHydro...
and United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
National Renewable Energy Laboratory
National Renewable Energy Laboratory
The National Renewable Energy Laboratory , located in Golden, Colorado, is the United States' primary laboratory for renewable energy and energy efficiency research and development. The National Renewable Energy Laboratory is a government-owned, contractor-operated facility; it is funded through...
.
VertiWind
VertiWind is a Vertical Axis Wind TurbineVertical axis wind turbine
Vertical-axis wind turbines are a type of wind turbine where the main rotor shaft is set vertically and the main components are located at the base of the turbine...
design created by Nenuphar http://www.nenuphar-wind.com/ and currently being tested by Technip http://www.technip.com/. See http://www.nenuphar-wind.com/press
Floating wind farms
, Japan plans to build a pilot floating wind farm, with six 2-megawatt turbines, off the Fukushima coastFukushima Prefecture
is a prefecture of Japan located in the Tōhoku region on the island of Honshu. The capital is the city of Fukushima.-History:Until the Meiji Restoration, the area of Fukushima prefecture was known as Mutsu Province....
of northeast Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
where the recent disaster
Fukushima Daiichi nuclear disaster
The is a series of equipment failures, nuclear meltdowns, and releases of radioactive materials at the Fukushima I Nuclear Power Plant, following the Tōhoku earthquake and tsunami on 11 March 2011. The plant comprises six separate boiling water reactors originally designed by General Electric ,...
has created a scarcity of electric power. After the evaluation phase is complete in 2016, "Japan plans to build as many as 80 floating wind turbines off Fukushima by 2020."
The cost is expected to be in the range of 10-20 billion Yen over five years to build the first six floating wind turbines.
Some foreign companies also plan to bid on the large floating wind farm that Japan hopes to build by 2020.
, Statoil plans to build a multi-turbine project in Scottish
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
waters utilizing the Hywind design.
The US State of Maine
Maine
Maine is a state in the New England region of the northeastern United States, bordered by the Atlantic Ocean to the east and south, New Hampshire to the west, and the Canadian provinces of Quebec to the northwest and New Brunswick to the northeast. Maine is both the northernmost and easternmost...
solicited proposals in September 2010 to build the world's first floating, commercial wind farm. The RFP is seeking proposals for 25 MW of deep-water offshore wind capacity to supply power for 20-year long-term contract period via grid-connected floating wind turbines in the Gulf of Maine
Gulf of Maine
The Gulf of Maine is a large gulf of the Atlantic Ocean on the east coast of North America.It is delineated by Cape Cod at the eastern tip of Massachusetts in the southwest and Cape Sable at the southern tip of Nova Scotia in the northeast. It includes the entire coastlines of the U.S...
. Successful bidders must enter into long-term power supply contracts with either Central Maine Power Company (CMP), Bangor Hydro-Electric Company
Emera
Emera Incorporated is a Halifax, Nova Scotia based energy and services company with 570,000 customers.It operates three utility subsidiaries:* Nova Scotia Power* Bangor Hydro Electric Company* Saint Lucia Electricity Services Limited...
(BHE), or Maine Public Service Company (MPS). Proposals were due by May 2011.
Some vendors who could bid on the proposed project have expressed concerns about dealing with the United States
Federal government of the United States
The federal government of the United States is the national government of the constitutional republic of fifty states that is the United States of America. The federal government comprises three distinct branches of government: a legislative, an executive and a judiciary. These branches and...
regulatory environment. Since the proposed site is in Federal waters
Outer Continental Shelf
The Outer Continental Shelf is a peculiarity of the political geography of the United States and is the part of the internationally recognized continental shelf of the United States which does not fall under the jurisdictions of the individual U.S...
, developers would need a permit from the Minerals Management Service
Minerals Management Service
The Bureau of Ocean Energy Management, Regulation and Enforcement , formerly known as the Minerals Management Service , was an agency of the United States Department of the Interior that managed the nation's natural gas, oil and other mineral resources on the outer continental shelf...
, "which took more than seven years to approve a yet-to-be-built, shallow-water wind project
Cape Wind
The Cape Wind Project is an approved offshore wind farm, on Horseshoe Shoal in Nantucket Sound off Cape Cod in the U.S. state of Massachusetts, proposed by a private developer, Cape Wind Associates, the brainchild of Jim Gordon and a Limited Liability Company set up as a joint business venture...
off Cape Cod
Cape Cod
Cape Cod, often referred to locally as simply the Cape, is a cape in the easternmost portion of the state of Massachusetts, in the Northeastern United States...
," and is also the agency under fire in June 2010 for lax oversight of deepwater oil drilling in Federal waters.
"Uncertainty over regulatory hurdles in the United States ... is 'the Achilles heel' for Maine's ambitions for deepwater wind."
External links
- Far Offshore Renewables: www.faroffre.com
- Arcadis
- Kusan
- Ritec
- Sway
- Nancy Stauffer (MIT): Giant wind turbines, floating out of sight. 2006 preliminary design with 5 MWe turbine units mounted 90 metres above the sea with massive 140 metre-diameter blades; MIT-NREL design.
- Statoil: Hywind floating wind turbine
- Nautica Windpower: Floating wind turbine system
- Floating Support Structures: LORC Knowledge