Technology developments and R&D landscape:
Research overview from Risø
Peter Hauge Madsen
Wind Energy Division, Risø DTU
The Technical University of Denmark
Presented at
EU offshore wind industry - a Carbon Trust/EWEA event
1
Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
Wind Energy Division - Risø DTU
Technical University of Denmark
• Windpower Meteorology
• Aeroelastic design
methods
• Wind Turbine Structures
• Offshore Wind Energy
• Remote sensing &
Measurements
WIND ENERGY
DIVISION
INTERNATIONAL
CONSULTING
Meteorology
2
Aeroelastic
Design
Risø DTU, Technical University of Denmark
• Windpower control &
integration
EDUCATION
Wind
Turbines
• Certification Scheme
Wind Energy
Systems
Test &
Measurement
Presentation name
17/04/2008
”Wind Energy Roadmap” in the EC Communication
of Financing Low Carbon Technologies.
TPWind priorities 20102012:
• Development and
testing of new
structures
• Automation (industrywide study)
• Technology transfer
from oil & Gas
3
Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
Research, development and demonstration
challenges – Danish MEGAVIND strategy
4
Target to make offshore wind power competitive with conventional coalfired power by 2020 (50 % reduction in cost).
Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
EERA JP on Wind Energy
5
Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
EERA JP on Wind Energy
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Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
EERA
JPWE
EERA
JP on
Wind Energy
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Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
Wind Energy Division - Risø DTU
Technical University of Denmark
DTU BYG
WIND ENERGY
DIVISION
DTU IMM
DTU MEK
INTERNATIONAL
CONSULTING
EDUCATION
Offshore
Wind
Energy
Meteorology
Aeroelastic
Wind
Wind Energy
Design
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Risø DTU, Technical University of Denmark
Turbines
Systems
Test &
Measurement
Presentation name
17/04/2008
Risø DTU – Offshore Wind Energy R&D
priorities
• Marine wind, wave and current conditions
– Characterize the geophysical processes,estimate local
conditions and develop design basis
• Wakes in offshore wind turbine farms
– Characterize and model wakes (performance and loads) in
relation to interaction between turbines, between farms and
large scale climate effects
• Installation and maintenance
– Methods, models and tools to support installation and
maintenance incl. Wind wave prediction, remedial and
preventive maintenance and condition monitoring
• Integrated design tools
– Integrated aero-hydro-servo-elastic tools incl. wave
loads,soil-structure and fluid-structure interaction
800
700
Power (MW)
600
• Offshore wind integration
500
HRB
HRA
HR2
HR1
400
300
200
– Models and tools for design and control of offshore grid and
clusters
100
0
28/1-2000
29/1-2000
30/1-2000
31/1-2000
1/2-2000
Time
• New concepts
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Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
Offshore Wind Conditions
Lidar wind data and
model from Horn’s
Reef offshore
Satellite winds
showing the
wake at Horn
Reef wind farm.
Mean wind
speed map using
satellite Envisat
ASAR.
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Risø DTU, Technical University of Denmark
• Ocean winds
• Lidar observations and
modelling
• Wind resource
mapping using satellite
data
• Mesoscale modelling
• Meteorological mast
observations
• Wind farms shadow
effect
• Satellite observations
Presentation name
17/04/2008
Horns Rev offshore site
Courtesy: DONG Energy
and Alfredo Peña, Risø DTU
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Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
Wind loads dominated by wake effects
CFD – Large eddy
simulation
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Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
Fuga – a new, linearized wake model
• Solves linearised RANS equations
• Closure: mixing length, k-e or ’simple’ (nt=ku*z)
• Fast, mixed-spectral solver using pre-calculated look-up tables (LUTs)
• No computational grid, no numerical diffusion, no spurious mean
pressure gradients
• Integration with WAsP: import of wind climate and turbine data.
• 105 times faster than conventional CFD!
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Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
User friendly GUI
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Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
Validation: Horns Rev I.
1.00
270+-7.5
270+-12.5 Fuga
0.90
Normalized prod.
Fuga
270+-17.5 Fuga
270+-7.5
0.80
Data
270+-12.5 Data
270+-17.5 Data
0.70
0.60
0.50
0.40
1
2
3
4
5
6
7
8
9
10
Row number
Simple closure: nt=ku*z
No adjustable parameters!
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Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
Validation: Nysted.
1.10
273+-7.5
Fuga
273+-12.5
Fuga
273+-17.5
Fuga
273+-7.5
Data
273+-12.5
Data
273+-17.5
Data
Normalized production
1.00
0.90
0.80
0.70
0.60
0.50
0.40
1
2
3
4
5
6
7
8
Row number
Simple closure: nt=ku*z
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Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
Downwind Speed Recovery
• FUGA - predicts a much ”slower” speed recovery than standard wake
models.
• For HR rec.distance is about 16 km; somewhat slower than observed
4)
Normalized wind speed through the wind
farm and behind the wind farm compared to
measurements at Horns rev. Full curves are
canopy-CFD-model predictions.
_______________________________________________________________________________________
4)
R.J.Barthelmie et al., ” Flow and wakes in large wind farms: Final report for UpWind WP8”. Risø-R1765(EN) (2011).
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Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
Design of offshore wind turbines
– Offshore wind turbines are not onshore wind turbines!
• hydrodynamic loads, sea ice, long periods at standby
– Offshore wind turbines are not oil rigs!
• wind loads, shallow water, dynamics, unmanned
– Marriage of expertise from wind power and offshore
engineering industries
– Technology Risks
• Improve confidence with which offshore wind farms can be financed
and implemented
rotor-nacelle assembly
tower
tower
support
structure
platform
water level
sub-structure
sub-structure
pile
sea floor
pile
seabed
foundation
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Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
Standards for Offshore Wind Turbines
•Onshore wind turbines
– IEC 61400-1, Edition 3
•Offshore wind turbines
–
–
–
–
IEC 61400-3
GL Regulations for Offshore WECS, 1995
DNV, Design of Offshore Wind Turbine Structures, OS-J101, 2007
GL Wind, Guideline for the Certification of Offshore Wind
Turbines, 2005
•Offshore structures – petroleum and natural
gas industries
–
–
–
–
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ISO
ISO
ISO
ISO
19900,
19901,
19902,
19903,
General Requirements for Offshore Structures, 2002
Specific Requirements for Offshore Structures, 2003
Fixed Steel Offshore Structures, 2004 (DIS)
Fixed Concrete Offshore Structures, 2004 (DIS)
Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
Walney Offshore Wind Farm Project
Partners: Risø DTU, DONG, Siemens
1.
Large offshore wind farm being
constructed by DONG energy with
~50 machines in phase 1
2.
Siemens 3.6MW machines with
monopile foundations
3.
Average HH wind speed: 9.3 m/sec
4.
Water depth 19m –28 m
Objectives
1.
Database of loads measurements with correlated wind and wave
data
2.
Assessment of uncertainty in loads simulations to provide improved
structural reliability.
3.
Recommendations to international wind turbine standards on
offshore turbine design.
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Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
EUDP Walney Offshore Wind Farm Project
Measurements:
•
Nacelle mounted LIDAR
measuring wind speed at 2.5
rotor diameter in front of
turbine.
•
Wave and current
measurements near foundation
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Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
Benefits from the project and its need
1. Maturity of loads prediction on offshore wind turbines,
both on the support structure, as well as rotor nacelle.
•
•
•
Provides offshore turbine loads data for research purposes.
Provides for correlated wind and wave measurements for each
load data point.
One of the very few nacelle mounted LIDARs for offshore wind
turbines with accurate wind measurements
2. Cost effective foundations.
–
–
Improved accuracy for site specific loads prediction
Estimation of damping of the structure to mitigate fatigue and
extreme loads
3. Long term loads on the foundations
–
–
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Fatigue and ultimate strength requirement evaluations
Enables improved life prediction
Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
DEEPWIND – New EU Funded Program
Vertical axis wind turbine
Bottom mounted generator for weight savings
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Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
Combined floating wind- and wave energy
converter – Poseidon Experiment
PSO project, measurements and modeling: DONG, FPP, DHI and Risø DTU
3x GAIA 11kW. Downwind,
Free yaw and teetering
Grid connection
point
Wave energy
conversion device
Mooring point
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Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
Poseidon: Modeling Challenges
• Three rotors in one simulation
– Structural modeling already possible in the multi-body formulation
– Aerodynamic model updated to handle this
• Wake from upwind rotors
– Already possible with the dynamic wake meandering model in HAWC2
• Large water surface area
• Full coupled HAWC2-WAMSIM simulations
• HAWC2 validated aeroelastic code
• WAMSIM validated radiation/diffraction
code for dynamic of floating structures
from DHI
• WAMSIM recode to HAWC2 dll-interface
format
• Ordinary HAWC2 turbine model
• Ordinary WAMSIM model
• Full system solved by HAWC2
Risø Hawc2 Overview
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Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
Conclusions
• The development of offshore wind energy depends not
only on industrial development and demonstration –but
also on medium to long term research
• Site conditions very complex – the site specific design
conditions are derived in an ad-hoc and pragmatic way
• Integrated design tools exist but are primarily used to
demonstrate conservatism of approach
• Limited validation of design loads and response
• Deep water (> 30 m) is a challenge
• Deep water concepts under way
• Offshore wind is just at the beginning – all options are
open
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Risø DTU, Technical University of Denmark
Presentation name
17/04/2008
Thank you for your
attention
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Risø DTU, Technical University of Denmark
Presentation name
17/04/2008