From offshore oil and gas structures to marine renewable energy Finn Gunnar Nielsen, Statoil / University of Bergen
70 years anniversary seminar and celebration for
Professor Odd M. Faltinsen and Professor Torgeir Moan.
NTNU 19-20 May 2014
2014-04-22 Classification: Open
Outline
• Some memories
• Link between «classical» marine disciplines and marine renewables
• Challenges related to Marine renewables with focus on offshore wind
2014-04-22 2 Classification: Open
Development of floating platforms
Pentagone, 1970’s - 16 000 tons
Troll B, 1990’s 190 000 tons
Sevan, 2000’s 250 000 tons
Source: www.Sevanmarine.com
Source: NOU 1981: 11
Source: www.Statoil.com
2014-04-22 3 Classification: Open
Two milestones
Alexander Kielland accident 28.03. 1980
Faltinsen, O.M. and Michelsen, F., 1974. Motions of Large
Structures in Waves at Zero Froude Number, Int. Symp.
on the Dynamics of Marine Vehicles and Structures in
Waves, University College London.
Faltinsen, Odd M and Løken, Arne E. 1974.
NV459 wave forces on large objects of arbitrary form :
user's manual, DNV
2014-04-22 4 Classification: Open
A more recent challenge – free fall lifeboats
Key issues:
• Accelerations
• Pressure
• Forward speed
• Interaction with wind and
waves.
• Acceptable risk level
Challenges:
• Water entry & slamming
• Numerical methods
• Capacity of composites
• Maneuvering in extreme weather
• Wind loads
• Experimental techniques
• Probability of failure
• Perceived risk
• Medical issues
• …
….
2014-04-22 5 Classification: Open
Marine renewable energy
Source: European Science Foundation. Marine
Board. Vision document on Marine Renewable
Energy, 2010
2014-04-22 6 Classification: Open
«Classical» marine diciplines - Marine renewables Thrusters versus Tidal energy:
• Maximum thrust with minimum
torque.
• Maximum torque with minimum
thrust
Offshore platforms versus wave
energy:
• Minimum motions – avoid
resonance
• Maximize force in phase with
velocity – work at resonance
Offshore wind:
• Aerodynamics
• Control
• Elastic response
• Hydrodynamics
2014-04-22 7 Classification: Open
Marine operations
Ocean energy and wind energy: The technical potentials exceed the demand.
Source: IPCC SRREN, 2011
2014-04-22 8 Classification: Open
9
La Rance barrage, (North Brittany) , 1967
• Up to 13.5 meters height difference
• 22km2 reservoir
• 24 turbines, D= 5.3m, 10 MW each
• 600 GWh/y (average “capacity factor” of 0.29).
• Coastal & river device
• (peak flow > 10 times river flow)
2014-04-22 9 Classification: Open
Tidal range
Source: IPCC SRREN 2011
2014-04-22 10 Classification: Open
Resources Waves
Average energy densities:
20 – 100 kW/m wave front
Source: World Energy Council
2014-04-22 11 Classification: Open
Extraction of wave energy. Main principles
Falnes: “In order for
an oscillating system
to be a good wave
absorber it should be
a good wave
generator’’.
From: Babarit,
Introduction to Ocean Wave Energy Conversion, 2009
2014-04-22 12 Classification: Open
Array of point absorbers.
• Fred Olsen, “Buldra”. (Norway
2004-)
− Array of heaving buoys.
Semisubmersible
2014-04-22 13 Classification: Open
14
Attenuator - Relative motion – Pelamis (750 kW device)
2014-04-22 14 Classification: Open
Size of wind turbines
Source: EWEA
2014-04-22 15 Classification: Open
Installed offshore wind turbines in Europe – by country
Source: EWEA 2013
Globally Land + offshore,
end 2012:
284 GW installed (+19%)
Offshore (EU), end 2013:
6.6 GW (+34%)
2014-04-22 16 Classification: Open
Moving into deeper water – The Oil industry did it 60 years ago…
Source: NREL
2014-04-22 17 Classification: Open
Foundation costs - current image
2014-04-22 18 Classification: Open
Norway 1 unit (west of Karmøy) Hywind Demo 2.3MW – Since 2009
World’s first floating multi-megawatt wind turbine.
Developed by Statoil.
Project started in 2003
Siemens 2.3 MW turbine
Operating since September 2009.
Capacity factor >50% In 2011
Experienced wind of 40 m/s and Hs > 9.0 m
Measurements at >200 channels
Floater motions have no negative impact on
turbine performance
2014-04-22 19 Classification: Open
Production during a storm.
• 24 hour period during
storm “Dagmar”, Dec
2011
• Avg. wind speed 16
m/sec
• Max wind speed 24
m/sec
• Max significant wave
height 7.1m
• Power production 96.7%
of rated
2014-04-22 20 Classification: Open
Next step: Scotland
2014-04-22 21 Classification: Open
A simplistic view on scales – aerodynamics
Mesoscale
10000 -10 km
Days -Hours
Park scale
10 -1 km
20 min - 20 sec
Rotor scale
200 - 50m
10 – 2 sec
Blade scale
5 - .5m
0.5 – 0.01 sec
Factor O(20*E06) on time and length scale
2014-04-22 22 Classification: Open
Wake, interaction effects and dynamic loads.
From Horn’s rev.
Source: Ingeniøren, DK March 2009
Theodorsen (1897 – 1978)
Dynamic lift effects
Hydrofoil vehicles
Wind turbine blades
….
2014-04-22 23 Classification: Open
Shallow water challenges
− Steep and breaking waves
− Current
− Refraction
2014-04-22 24 Classification: Open
Slamming waves on monopiles
• Source: WiFi JIP, Deltares, March 2014
Horizontal force / wave height
Horizontal force
2014-04-22 25 Classification: Open
To succeed: Use what we learned over the last 40+ years.
New and critical operations
Complicated system dynamics
Extreme non-linearities
2014-04-22 26 Classification: Open
Presentation title
Presenters name
Presenters title
E-mail address ……@statoil.com
Tel: +4700000000 www.statoil.com
Thanks to Odd and Torgeir for their contributions
within Marine hydrodynamics and structures
during 2*40+years.
–
Paving a way from offshore oil and gas to marine
renewables.
2014-04-22 27 Classification: Open
