Design and load calculations for Offshore of a 5 MW Turbine

1
REpowers experience with the worlds first
deepwater offshore wind turbine Peter Quell, Marc
Seidel REpower Systems AG EWEC 2007, Milano,
2007-05-09
2
Introduction
3
Outline

• Outline
• Key site parameters
• Wind turbine technology
• Substructure design
• Onshore assembly of the turbine
• Installation
• Access system
• Experiences
• Progress of the 5M

4
Key Site Parameters

• Key site parameters
• Site Moray firth, 25 km to coast line
• Mean wind speed Uavg 10m/s
• Extreme wind Vref 50m/s
• Water depth 50m (design water level)
• Extreme wave 15.6m

5
REpower 5M Offshore Wind Turbine

• Rated power 5 MW
• Rotor diameter 126 m
• Mean wind 10.5 m/s
• Extreme wind 50.0 m/s(10min. mean)
• Design Assesment IEC 1b

• Masses
• Blade 18 to.
• Nacelle (incl. Rotor) 430 to.
• Tower 60m-offshore ca. 200 to.
• Tower HH 117m ca. 500 to.

6
REpower 5M Offshore Wind Turbine

• Offshore Features
• Dehumidifiers installed in tower and nacelle to
  keep the relative humidity RH at 50 and avoid
  condensation
• No flow of external air through nacelle
• Fully enclosed 33kV transformer in the rear of
  the nacelle
• Corrosion protection according to Norsok M 501
  standard
• Marine crane in the nacelle for lifting up to 3.5
  tonnes
• Helihoist for helicopter service

7
Substructure Design and Fabrication
less elements - high wave loads by big
diameters - heavy - complex connection points
low wave loads by hydr. transparency stiff
but light weight standardized tubes collision
behaviour - many elements
- like CCT - unsymmetric design, complex dynamic
behaviour
8
Substructure Design

• Joint design process
• Load and dynamic simulation by REpower using an
  integrated model of Flex5 for the turbine and
  ASAS for the sub structure
• Basic design of sub structure by OWEC Tower
• Verification for REpower 5M and optimization by
  OWEC/REpower
• Detailed design and documentation by AMEC

195m
70m
17m
sea level
45m
9
Substructure Design
Transition node 163 to.
Jacket 360 to.
pile sleeves 160 to.
10
Jacket Installation
Transportation and lifting the sub structure
11
Jacket Installation
Pile before installation in the pile sleeve
12
Jacket Installation
Pile hammer
Pile swager
13
Jacket Installation
Waiting for the turbine
14
Onshore Assembly
Erection of the whole turbine in the harbour
15
Turbine Installation
BOWTIS Installation system (by The Engineering
Business Ltd)
Spreader Beam
Tower interface frame
16
Turbine Installation
Turbine Sail-Out
17
Turbine Installation
18
Turbine Installation
Soft landing system with hydraulical damping
system in the interface frame
Landing arms on the transition node
19
Turbine Installation
20
Access System
ERIC Emergency Rapid Intervention Craft
ERIC on the oil platform
ERIC connecting to the turbine
21
Experiences

• Experiences
• Offshore-WEC installation in deep water is
  feasible
• Jacket substructure as a proven and well suited
  foundation for deep water installations
• One-piece installation as a feasible option, esp.
  for series production
• Floating crane depends on calm weather
• Small weather periods for installations
• Optimised preparation and processes
• Availability of installation equipment
• Access as the most critical challenge
• Optimised boat landing
• Standard regulations for using helicopters

22
Progress of the 5M

• Prototype in operation since end of 2004
• Availability 2005 and 2006 gt 95
• Production in January 07 2.600 MWh
• Validation program completed, expectations
  fulfilled
• Power curve, grid quality, sound
• Load measurement compagn
• Component validation
• 2006 erection of 3 turbines (Beatrice, Cuxhaven)
• Serial production starting. Next Projects
• 5x 5M in Büttel / Germany
• 1x 5M in Bremerhaven

23
Thank you for your attention!
Introduction Dynamics Substructure
influence Impact of waves (FLS) Impact of waves
(ULS) Local vibrations Summary
Thank you for your attention!
The Beatrice Offshore Wind Farm Demonstrator is
part of the DOWNVInD Project under the FP6
Programme of the European Commission