Potential life-cycle cost reductions for offshore floating wind energyMichael Borg

DTU Wind Energy

Technical University of Denmark

International Workshop on Life-Cycle Costing of Offshore Wind Turbines and Farms

October 1st 2015, University of Maryland

01 October 2015

Outline

• Introduction

• Offshore wind life cycle value chain

• Floating wind turbine system

• Alternative concepts

• Improved design tools for cost reduction

• Case studies

• Conclusions

2

01 October 2015

Introduction

3

01 October 2015

Introduction

Why offshore wind energy?

Need for more sustainable energytechnologies

Wind energy is one promisingtechnology

Offshore: more wind and lessobstacles for larger turbines

4

01 October 2015

Introduction

Why offshore wind energy?

Need for more sustainable energytechnologies

Wind energy is one promisingtechnology

Offshore: more wind and lessobstacles for larger turbines

5

01 October 2015

Introduction

Why floating offshore wind energy?

• Fixed foundations not economicallyfeasible in water depths >50m

• Transition to floating foundations

• Trend so far to ‘marinize’ onshore wind turbines

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01 October 2015

Offshore Wind Value Chain

Contributors to the final cost of energy

Site Development

Systems Design

Procurement&

Manufacturing

Transport &

Installation

Operation & Maintenance

Decommisioning

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01 October 2015

Offshore Wind Value Chain

Contributors to the final cost of energy

Site Development

Systems Design

Procurement&

Manufacturing

Transport &

Installation

Operation & Maintenance

Decommisioning

8

01 October 2015

Floating wind turbine systems

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01 October 2015

Incident Wind

Waves

Currents

Elasticity

Station-keeping

Turbine control

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01 October 2015

Alternative concepts: HAWTs vs VAWTs

• Two main types of wind turbines

– Horizontal-axis

– Vertical-axis

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01 October 2015

HAWTs vs VAWTs

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01 October 2015

HAWTs vs VAWTs

0

40

80

120

160

-120 -80 -40 0 40 80 120

Vert

ical d

istan

ce (m

)

Hoizontal distance (m)

REpower 5MW HAWT(swept area: 12,469m2)

NOVA 5MW design D19(swept area: 11,139m2)

Nacelle

Nacelle

Thrust force CP

Thrust force CP

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01 October 2015

HAWTs vs VAWTs

0

40

80

120

160

-120 -80 -40 0 40 80 120

Vert

ical d

istan

ce (m

)

Hoizontal distance (m)

REpower 5MW HAWT(swept area: 12,469m2)

NOVA 5MW design D19(swept area: 11,139m2)

Nacelle

Nacelle

Thrust force CP

Thrust force CP

14

01 October 2015

HAWTs vs VAWTs

0

40

80

120

160

-120 -80 -40 0 40 80 120

Vert

ical d

istan

ce (m

)

Hoizontal distance (m)

REpower 5MW HAWT(swept area: 12,469m2)

NOVA 5MW design D19(swept area: 11,139m2)

Nacelle

Nacelle

Thrust force CP

Thrust force CP

More details in (Borg, 2015)

15

01 October 2015

HAWTs vs VAWTs

0

40

80

120

160

-120 -80 -40 0 40 80 120

Vert

ical d

istan

ce (m

)

Hoizontal distance (m)

REpower 5MW HAWT(swept area: 12,469m2)

NOVA 5MW design D19(swept area: 11,139m2)

Nacelle

Nacelle

Thrust force CP

Thrust force CP

More details in (Borg, 2015)

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01 October 2015

Improved design tools for cost reduction

Offshore wind value chain

Contributors to the final cost of energy

Site Development

Systems Design

Procurement&

Manufacturing

Transport &

Installation

Operation & Maintenance

Decommisioning

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01 October 2015

Improved design tools for cost reduction

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01 October 2015

Improved design tools for cost reduction

Based on (Schløer, 2014)19

01 October 2015

Improved design tools for cost reduction

Based on (Schløer, 2014)20

01 October 2015

Improved design tools for cost reduction

Based on (Schløer, 2014)21

01 October 2015

Case studies

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01 October 2015

DeepWind case study

• EU Future Emerging Technologies 4-year R&D project

• 11 international partners

• Floating VAWT concept. Design methodology:

– Simple and more reliable through reduced no. of components

– Design for mass production manufacturing

– Upscaling potential

• Results:

– 5MW system detailed design

– 20MW conceptual design

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01 October 2015

DeepWind case study

• EU Future Emerging Technologies 4-year R&D project

• 11 international partners

• Floating VAWT concept. Design methodology:

– Simple and more reliable through reduced no. of components

– Design for mass production manufacturing

– Upscaling potential

• Results:

– 5MW system detailed design

– 20MW conceptual design

• More details in (Paulsen, 2015)

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01 October 2015

DeepWind LCOE model

• Levelized cost of energy model, based on (Myhr, 2014)

• Life cycle decomposed into 5 stages:

– Development & consenting

– Production & acquisition

– Installation & commissioning

– Operation & maintenance

– Decommissioning

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01 October 2015

DeepWind LCOE model

• Combining capital and operating costs for a 25-year lifetime and range of wind farm size

60

62

64

66

68

70

72

74

0 200 400 600 800 1000 1200

LC

OE

(€/

kW

h)

No. of WT units

LCOE (€/kWh)Unit capital costs breakdown

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01 October 2015

DeepWind LCOE model

• Uncertainty study of 100-unit 500MW wind farm

• Introduced more favourable and less favourable ranges of input values

• Results:

– More favourable = €59/MWh

– Reference = €63/MWh

– Less favourable = €75/MWh

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01 October 2015

INFLOW concept

• EU FP7 project with 8 partners

• Industrialization setup of a Floating Offshore Wind Turbine – 2MW floating VAWT concept

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01 October 2015

INFLOW concept

• EU FP7 project with 8 partners

• Industrialization setup of a Floating Offshore Wind Turbine – 2MW floating VAWT concept

• Exploit integrated system design to reduce LCOE

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01 October 2015

INFLOW concept

• Commissioning of single 2MW prototype in Mediterranean Sea near France.

• Gain experience in:

– Developing novel offshore wind turbine

– Instrumentation

– O&M procedures

– O&M costs

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01 October 2015

Future Challenges

• Implementing integrated design methodologies

• ‘Class’ design versus site-specific design → mass production

• Quantifying concept-dependent O&M costs

• Convincing industry to support alternative concepts

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01 October 2015

Conclusions

• Explore alternative concepts for significant change in cost of deep-sea offshore wind energy

• Holistic and integrated system design vs. segregated design

• Reducing costs through improved design tools

• DeepWind floating VAWT concept case study

• INFLOW floating VAWT concept

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01 October 2015

Thank you for your attention

Acknowledgements

EU FP7 DeepWind (2010-2014) - This project has received funding from the European Union’s Seventh Programme for research, technological development and demonstration under grant agreement No 256769

EU FP7 INFLOW (2011-2017) - This project has received funding from the European Union’s Seventh Programme for research, technological development and demonstration under grant agreement No 296043

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01 October 2015

References

(Borg, 2015) Borg M, Collu M (2015) A comparison between the dynamics of horizontal and vertical axis offshore floating wind turbines, Phil. Trans. R. Soc. A, 373, 20140076.

(Myhr, 2014) Myhr A, Bjerkseter C, Ågotnes A, Nygaard TA(2014) Levelised cost of energy for offshore floating wind turbines in a life cycle perspective, Renewable Energy, 66, pp.714-728.

(Schløer, 2014) Schløer S, Paulsen BT, Bredmose H (2014) Application of CFD based wave loads in aeroelasticcalculations, 33rd International Conference on Ocean, Offshore and Arctic Engineering, San Francisco, USA.

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