洋上風力発電装置の現状と新型式の提案 · Low tip speed ratio of VAWT(half of HAWT tsr) • Lightning strike Off -axis drive train and generators can be easily H

二次電池社会システム研究会

第12回分科会 2012/09/19 於東京大学工学部2号館

洋上風力発電装置の現状と

新型式の提案

Hiromichi Akimoto, Dr. Eng.Division of Ocean Systems Engineering (OSE),

Korea Advanced Institute of Technology (KAIST),

Email: [email protected]

秋元博路

講演者の紹介

• 工学博士 (船舶工学、東京大学 1996)• 職歴

▫ 鳥取大学 (1996.04-2005.03)• 応用数理工学科

• 助手、講師、助教授

▫ 東京大学（2005.04-2011.10)• 環境海洋工学専攻→システム創成学専攻

H. AKIMOTO, Division of Ocean Systems Engineering (OSE), Korea Advanced Institute of Science and Technology

• 環境海洋工学専攻→システム創成学専攻

• 准教授

▫ Korea Advanced Institute of Science and Technology (KAIST) (2011.10-現在)

• Division of Ocean Systems Engineering• Visiting Foreign Professor

• 研究分野

流体数値シミュレーション(船舶、航空分野)、洋上再生可能エネルギー(風力、潮流

、海流、波力)、超高速船、表面効果翼船(WISES, WIG)、物流シミュレーション

KAIST

• Korea Advanced Institute of Scienceand Technology (韓国科学技術院)▫ 大学院が主体

▫ 予算397Million USD(2007)(政府3割、獲得資金3割)

• 所在地: Daejeon


• 所在地: Daejeon▫ 大田広域市

▫ ソウルからKTXで1時間

▫ 政府機能の一部が置かれる

▫ R&D集積地の1つ

• KIOSTI( 旧名 KRISO, KORDI, MOERI)• Samsung の船舶関連研究施設など

3

洋上風力発電洋上風力発電洋上風力発電洋上風力発電


Cost of renewable energy

H. AKIMOTO, Division of Ocean Systems Engineering (OSE), Korea Advanced Institute of Science and Technology 5

再生可能エネルギーによる発電コスト（出典：「World Energy Outlook 2009, IEA (2010)」よりNEDOが作成）

Increasing demand of offshore windDeep water wind turbine

development


Increasing demand of floating wind turbine• Limited shallow water area in some countries like Japan• Major concept is floating horizontal axis wind turbine (HAWT)

▫ Difficult to scale up▫ Top heavy configuration increases installation cost

(NREL)Floating wind turbine concept(IHIMU and Univ. Tokyo)

Limited shallow water in Japan


Maps around Europe and Japan in the same scale(from satellite view of Google map)

Limited shallow water in Japan


Maps around Europe and Japan in the same scale(from satellite view of Google map)

HVDC connection in Europe

• High Voltage Direct Current connection

• Leveling fluctuation of renewable energies

• Electricity transfer from

•再生可能エネルギーの

多国間連携のため、洋上

にも系統電源ラインがで

きつつある

•洋上送電コストの前提が


Norway to Germany (580km) is working and is profitable

• Distance between Korea and Japan is only 200km

9

HVDC connections in EuropeGreen= approved project, Red = existing, Blue= Options under consideration

•洋上送電コストの前提が

日本と異なる

Installed offshore wind power


2011 Annual report, GWEC （2012）

• UK is the top runner of offshore wind power

Offshore wind farm in Japan?


Efficient installation of bottom fixed turbines is almost impossible in Japan

11

Horns Rev (Horns Reef) wind farmVestas V80 2MWx80 = 160MW, 2002

offshore wind power KASUMI

ウィンド・パワーかみす洋上風力発電所

40-50m offshore, 2MWx7 (2Mx8 2nd farm under construction)

Largest wind farm in the world


Greater Gabbard 500MW wind farm On sandbanks 23km offshoreSiemens 3.6MW x 140

Floating wind turbine

• ヨーロッパで見られる大規模な着床式洋上風車

の発電施設は、日本では実現しない

• 需要増に伴い深水域での風力発電が必要

• 日本での利用には、「浮体式風車」が不可欠


着床式は、陸上風車の延長だが、浮体式は、

土地の造成(浮体建造)揺れる事を前提とした設計

が必要

13

Floating wind turbine


How to reduce cost?• Smaller float• Swayable turbine tower

WindFloat (PrinciplePower): Sway concept (Sway)Passive tilt

Hywind (StatoilHydro)Spar buoy type

国内の浮体式洋上風車への取り組み


環境省環境省環境省環境省-京都大学京都大学京都大学京都大学

五島列島椛島（かばしま）沖合2km、ハイ

ブリットスパーブイ, 系統連携, 100kW(2012/8), 2MW(2013/5)

経済産業省経済産業省経済産業省経済産業省-福島洋上風力コンソーシアム福島洋上風力コンソーシアム福島洋上風力コンソーシアム福島洋上風力コンソーシアム

丸紅, 東大, 三菱商事, 三菱重工, IHI MU, 三井造船、新日鐵、日立製作所、古河電工、清

水建設、みずほ情報総研

Substation+2MW (2012), 7MWx2 (-2015)

国内の浮体式洋上風車への取り組み

その他その他その他その他

国土交通省国土交通省国土交通省国土交通省


福岡市福岡市福岡市福岡市-九州大学九州大学九州大学九州大学風レンズ風車風レンズ風車風レンズ風車風レンズ風車

博多湾、2011より実証実験中、風レンズ

風車(3kWx2)+太陽電池(1.5kW)+生け

簀

シュラウドの付加により、2～3倍の発電

(1.4～1.7倍のブレード長タービンよりも

低コストにできるか？)強風対策、支持構造の増加が課題

経済産業省、環境省、国土交通省がばらばら

に取り組む

漁業補償を考えると、農林水産省が入るべき

調整機関が無いと非効率なR&D投資

国土交通省国土交通省国土交通省国土交通省

港湾での風車利用

促進、建築基準策

定、国際標準への

取り組み

新形式新形式新形式新形式浮体式風力発電の提案浮体式風力発電の提案浮体式風力発電の提案浮体式風力発電の提案

再生可能エネルギーを採算可能エネルギーにするには


再生可能エネルギーを採算可能エネルギーにするには

浮体式風車実証試験の目的

• 実証、ビジネスモデルの確立

• 浮体式の標準化における発言力強化

問題点


• 標準化の目的は? (議論の不在)▫ 標準化に組み込まれた特許の収入、囲い込み?

• 差別化する独自技術の不明瞭さ

▫ 台風に耐えられる性能は、標準になりにくい

• 他の国なら、そのような海域に風車はおかない

▫ プロジェクトの時間スケール(スピード感)は適切か

18

浮体式風車のコンセプトに対する疑問

洋上風車の経済性に関するロジック

• 陸上よりも強風が安定的に得られる(高い設備利用率)• 道路ではなく海上を輸送�大型化可能�効率向上

• 広大な利用可能海域

しかし、


しかし、

• 風の強い海域 � 建設、保守作業の日数確保が困難

• 大容量、軽量、コンパクトな発電、動力伝達が必要(難しい)

• 10MW超大型化案は着床式、浮体式の大型化は困難

• 漁業補償の交渉可能な場所は限定的

▫ 経済性の低い風車で先に占められてしまうおそれ

▫ 「海表面積あたり発電量」が重要な指標となる

19

Fundamental questions of floating wind turbine

In good wind power site, we expect high wind and rough sea state

• Top heavy floating structure?• Need to keep its upright position?• How many available days for


• How many available days for construction?

Is the concept right answer in ocean engineering?

22

• ボートの上で立ち上がってはいけない

• 洋上では揺れる事を前提に

• 銀座(高価な洋上施設上)で風車を回しても赤字

海洋工学の基礎から外れた不自然さ海洋工学の基礎から外れた不自然さ海洋工学の基礎から外れた不自然さ海洋工学の基礎から外れた不自然さ

垂直軸型風車


Vertical axis wind turbine (VAWT)▫ Low center of gravity, non-directional（no yaw control）

Advantages in floating configuration

Vertical axis wind turbine (Nanuphar)

23

Deepwind, (DTU, Riso)20MW VAWT on a rotating spar buoy

23

NOVA (WindPowr Ltd.)Huge VAWT concept

Floating Axis Wind Turbine (FAWT)

Central columnBlades

Wind

3MW FAWT5MW Vertical axis turbine


Floater

• Inclined axis floating turbine (rotating spar buoy)• Passively adjustable tilt angle to wind power• Low requirement of structural strength• Reduced total device size

Akimoto et al. (2011)

(a) HAWT (b) VAWT-S (c) VAWT-C (e) FAWT(d) Deepwind

Floating VAWT concepts


: Bearing and drive train

Rotating float

Stationeryfloat

3MW FAWT designFront view Side view


• 85.1m height, 76m max. diameter, 7.5m/s wind

• Straight or helical bladesCost of energy 0.069USD/kWh (comparable to land based wind turbines)

Torque convertersUpright condition Tilted condition

20ton


• Contacting rollers receive torque from the turbine axis

• Multiple roller units allowing the tilt of turbine axis

• Off-axis and lightly loaded drive train

244ton

風力発電の主要な問題の解消

• Cost• Bird strike▫ Low tip speed ratio of VAWT(half of HAWT tsr)

• Lightning strike▫ Off-axis drive train and generators can be easily


▫ Off-axis drive train and generators can be easily protected from the lightning shock

• Designable aspect ratioof sweep area

• No R&D for high-capacity drive• Less concern of noise (in offshore)

30

Electric current

Publications

http://environmentalresearchweb.org/cws/article/news/47975

• Environmental ResearchLetters and its web news

• RECHARGE• Selected in “2011

Highlights” of Environmental Research Letters


http://www.rechargenews.com/business_area/innovation/article298770.ece

• Appeared in an AljazeelaTV document on Korea (as one of research topics in KAIST)

• YouTube: “Floating axis wind turbine” http://youtu.be/L6wdvCQ5zJMhttp://youtu.be/Z11CvB764CI

Evaluation of economic performanceFAWTFloating 3MW turbine• Rotor diameter 76m• Turbine height: 85.1m

HAWTOffshore, shallow-water,3-MW baseline turbine (NREL)

• Rotor diameter: 90m• Hub height: 80m


• Hub height: 80m

Cost comparison with horizontal axis turbineCost components in 3MW rated power HAWT FAWTRotor 477 726Drive train, nacelle 1425 659Control, Safety Sys., Monitor, Pitch mech. & bearings 60 60Tower/Central column 415 221Marinization (13.50% of Turbine & Tower cost) 321 225

Monopile foundation/Support Structure / Float 1114 1712Transport, Install, Electrical interface, Assessment 1835 1835Scour Protection 204 0Surety Bond (Decommissioning - 3.0% of ICC) 180 168

Initial capital cost8.3% reduced


Surety Bond (Decommissioning - 3.0% of ICC) 180 168Offshore Warranty Premium 357 250

(Subtotal: Initial capital cost ICC) (6386) (5855)Levelized Replacement Cost (LRC) (USD per year) 55 55O&M (USD per turbine/yr) 215 145Bottom Lease Cost (USD/year) 12 12

(Subtotal: Annual Operating Expenses [USD/year]) (282) (212)Cost of Energy (USD/kWh) 0.095 0.069

Based on the cost estimation of NREL, USA, 2006 [1000USD unit]

Annual operating expense 24.8% reduced

Cost of energy27.4% reduced

Cost comparison with horizontal axis turbine

In comparison to 3MW bottom fixed HAWT(NREL 2006)

• Initial investment (-8.3%)▫ Simplified drive train, No yaw control and tower▫ Float is still expensive than seabed construction


• Operating cost (-24.8%)▫ No special utility ships (ex. crane ship)(proportional to the initial investment in the preliminary study)

• Cost of energy (0.067USD/kWh, -27%)▫ Still higher than the target of land based wind turbine▫ Possible improvement (optimization, scale up, stable

offshore wind power)

34

Concept for scaling up (2x3MW)


Twin turbine:• Counter rotating turbines cancel

reaction torque of generators• Reduce total cost of anchoring

• Cancelling reaction torque of generators

• Increased efficiency 20%• Repulsive Magnus force

between two turbines

Counter rotating twin turbine


between two turbines• Reduction of total

mooring cost• Higher utilization of sea

surface

37

Concept for small power plant

• Foldable blades• Transportable• Endurance in heavy weather

• Deployable


70kW plant (25m height)Deployable power plant for disaster area and ocean platform

38

• Deployable• Disaster area• Ocean platforms

FAWT farms for Korean PeninsulaEast side coastal area• Deep water depth• Expected rapid energy

demand increaseNorth Korea: 51% population, 5.4% electricity generation of South Korea

• Electricity transfer among

Suitable site for FAWT and electricity exports


• Electricity transfer among nearby countries is essential for utilizing fluctuating wind as in Europe

• High Voltage Direct Current connection to Japan should be started in the near future

40

Map of wind farms in Korea (www.thewindpower.net)

200km

HVDC connection in Europe

• High Voltage Direct Current connection

• Leveling fluctuation of renewable energies

• Electricity transfer from


Norway to Germany (580km) is working and is profitable

• Distance between Korea and Japan is only 200km

41

HVDC connections in EuropeGreen= approved project, Red = existing, Blue= Options under consideration

Additional applicationAdditional applicationAdditional applicationAdditional application

Floating Axis “Water” TurbineFloating Axis “Water” TurbineFloating Axis “Water” TurbineFloating Axis “Water” Turbine


Floating Axis “Water” TurbineFloating Axis “Water” TurbineFloating Axis “Water” TurbineFloating Axis “Water” Turbine

43

High density of energy in water

• 1000x density• Predictable power of

tidal stream• Stable ocean current

� Higher capacity


� Higher capacity factor

44

Marine Current Turbine Ltd., 2003

Inclined turbine concept

• Adjustable to stream power▫ Low structural requirement▫ Reduced support structure

• Non-submerged mechanics▫ Higher durability


▫ Easy maintenance

• Turbine surfacing▫ Pulling up turbine axis to

water surface for maintenance access

• Installation▫ On seaside structures or float

45

Comparison with existing conceptENERMAR

(Kobold turbine)

H=5m

Floating Axis Turbine

139kW40ton

25-30kW35ton


• Increased turbine height• Reduced floater size

Φ=6m

H=25m

Twin turbine (2MW) for Kuroshio Ocean Current▫ 1MW each at 2.5m/sec

current

Ocean current turbine


Cost of energy0.063USD/kWh

Applications

Lift up for maintenance

Transportation and maintenance accessmaintenance does not require diving work


Tidal generator farm12m height turbine for 15m depth shallow water

まとめ

1. 着床式洋上風車は、国内設置に限界

2. 漁業補償の交渉可能な海域は限定的

経済性の低い風車で占められる事により、国内市場が終わっ

てしまう危険性

3. 浮体式は、水平軸型が主流だが、陸上風車の延長で

は限界がある


は限界がある

4. 浮動軸型風車(Floating Axis Wind Turbine)は、固

定概念を捨てる事により、低COEを狙う

5. 同概念は、水流タービンにも適用可能

河川流、潮流、海流用、low technology水力

洋上風力で電力貯蔵の必要性が高い（研究中）

49

Documents

洋上風力発電装置の現状と 新型式の提案 · Low tip speed ratio of VAWT(half of HAWT tsr) • Lightning strike Off -axis drive train and generators can be easily H

洋上風力発電装置の現状と新型式の提案 · Low tip speed ratio of VAWT(half of HAWT tsr) • Lightning strike Off -axis drive train and generators can be easily H