浮体式洋上風力発電

Blue H

Blue HはオランダのBlue H Technologies社によって、イタリアのプッリャ州の南東、陸地から21キロ、水深113メートルの南アドリア海洋上に2008年に設置された。実際に運用されたものとしては世界初となる浮体式洋上風力発電施設ではあるが、発電能力わずか80キロワットであり実用的な物ではなく、風力と海の状態をテストするためのプロトタイプ機である。設置されてちょうど一年後の2008年末に退役した。
Blue H Technologies社はこのプロトタイプ機において、「tension-leg platform」と呼ばれる係留システムと、2枚のブレードによるタービンを利用した。2枚のブレードによる風力タービンは3枚のブレードよりも大きな翼弦をとることができ、末端のスピードをより大きく出来るメリットがあったが、一方で騒音公害も大きくなるデメリットがあった。しかし人家から遠く離れた外洋では、騒音公害を気にする必要が無いのである。
2009年現在、Blue H Technologies社は退役したプロトタイプ機の後継となるフルスケールの商用の2.4 MWタービンをイタリアのブリンディジにて建設中である。2010年にはこのタービンを、プロトタイプを設置したのと同じ場所に設置する予定であり、それが38基(90MW)の浮体式洋上風力発電タービンからなるTricase洋上風力発電所における最初のタービンとなる予定である。

Hywind

Hywindは、スタトイルハイドロ社（現：エクイノール）によって2009年6月に供用された。実用的な大容量の浮体式洋上風力発電タービンとしては世界初の施設である。2009年6月、120メートルの高さを持つTechnip社製の浮体式のタワーと、2.3MWの発電能力を持つSiemens Wind Power(シーメンス)社製の風力タービンが、海が穏やかなスタヴァンゲル市近郊にあるÅmøyフィヨルドにて組み立てられた後、Karmøy村の南西10キロ、水深220メートルの地点まで曳航され、2年間のテストに供された。
基礎部分を所有するのはエクイノール社である。エクイノールのAlexandra Beck Gjorvは、「この実験はこれまでの洋上風力発電を別次元に引き上げる手助けとなるだろう（中略）浮体式洋上風力発電の潜在的なグローバル市場は巨大であり、そのコストをどれだけ下げられるかにかかっている」と語っている。
エクイノールはまた、「浮体式洋上風力発電は未熟であり商用化は厳しい」とも発言している。
この世界初の実用化された浮体式洋上風力発電タービンは、建設と設置に約4億クローネ(6200万ドル)もかかった。
Hywindは年間約9GWhの電力を生み出すと期待されていたが、実際には2010年度に7.3GWhの電力を供給し、11メートルの波にも無傷で耐え、ノルウェーの電力網に電力を供給し続けた。

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 winds and close proximity to large load centers (e.g. shorter transmission runs)."
2009年現在 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 dollars per megawatt to install, according to the World Energy Council.
2009年現在, 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.
2010年10月現在, 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.

アメリカ

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 are 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."

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 Agency (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 meters. 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.

DeepWind

Risø and 11 international partners started a 4-year program called DeepWind in October 2010 to create and test economical floating Vertical Axis Wind Turbines 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.

VertiWind

VertiWind is a Vertical Axis Wind 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