Spar Wind Turbine

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Outline

Introduction • Marine operation • Oil and gas industry vs. Wind industry • Challenges • Offshore wind (fixed/floating) Today-installation Wind farm installations • Cable-laying • Foundation installation • Substation installation • Turbine installation

Some examples fixed floating Assemble @ offshore/onshore New ideas Remarks and conclusions www.cesos.ntnu.no www.cesos.ntnu.no

Madjid –01.03.2011 Author – Centre for Ships andKarimirad Ocean Structures

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Marine operations Limited duration Transient condition May be interrupted not in extreme conditions Weather dependency

Design Installation (including transportation) Operation and maintenance

Requirements? ¾Standard, rules and regulations ¾Defined procedures ¾Skilled people ¾Software ¾Weather forecasting ¾Custom-made tools

Environmental conditions

¾Experience

www.cesos.ntnu.no www.cesos.ntnu.no


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Examples of marine operations (DNV)

Load Out: Transfer a structure from land onto a vessel Float on / Float off: Transfer a floating structure onto a vessel and vice versa. Float Out: Transfer a structure from a dry construction site to a self-floating condition. Launching: Cutting sea-fastening of a structure and slide down launch rails to a free floating condition. Lift off: Transfer a structure from a temporary construction site onto a transportation vessel. ROV /AUV operations: Work on subsea equipment, surveillance, bottom mapping. Piling: Secure a structure to sea bottom by driving piles into the soil. Positioning: Position a structure a predetermined location. Upending: Upend a floating structure. Lifting: Lift or support a structure by crane. Setting: Set down a structure, levelling and soil penetration. Towing: Pushing / pulling by tugs. Pipe laying: Laying pipe on the seafloor. Cable-laying www.cesos.ntnu.no www.cesos.ntnu.no


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Safety of Marine operations

Simo, Simulation of Marine Operations

PSA (PTIL): Gives rules and regulations for offshore oil activities. But: Does not regulate transportation or transfer of installation. IMO: Safety on sea in general. ISO/ NORSOK/ API / DNV: Standards, recommendations, rules. Combine Authority and company requirements. Operational safety: Internal control duty.

OFFSHORE SIMULATORS Anchor handling, lifting, etc.

Human error, 30% of accidents in MO

Insurance

Risk level

Warranty survey (GL Noble Denton, DNV) Credit: Finn Gunnar Nielsen www.cesos.ntnu.no www.cesos.ntnu.no


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Guidelines, rules and standards

Offshore is risky (not always) Risk = probability x consequences Simple operations with high redundancy

If the risk is intolerable!?

Marine Warranty Survey (is required by the insurer): • Assessment of the selected ships/barges and equipment • Marine operations / environmental conditions Design: Transport and Installation loads Securing quality during transport and installation in terms of the certification and on behalf of the client IEC, GL, DNV www.cesos.ntnu.no www.cesos.ntnu.no

GL Noble Denton, DNV

Survey during I&T they can stop the operations


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Guidelines, rules and standards DESIGN OF OFFSHORE WIND TURBINE STRUCTURES, DNV-OS-J101 DNV Rules for Planning and Execution of Marine Operations



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Oil industry vs. Wind industry One of a kind

Good knowledge from oil and gas technology

Goal: 4 GW per year (in Europe) 2-3 turbines per day should be installed

i.e. 80 turbines

However, challenges for wind: Requirements on costs and regularity Large lifting heights Assembly precision (Vessel motions) Shallow water! (draft limitation) Deep water (floating wind turbines) Effective and robust installation methods Limitation of capacity Weather window www.cesos.ntnu.no www.cesos.ntnu.no

Composite materials, Drive train/mechanical parts Sensitive to accident (ALS) Limited experience


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Offshore wind installation challenges Installation tolerance: Wind turbine suppliers (i.e. Siemens) Additional loading

Substructure inclination Positional tolerances of bolts Verticality of the mating flange +/-0.25 degrees

Limitation of operations (Weather window): Transport: 0.5 g – 1.0 g (direction-dependent) Hs < 4.0 m Towing: Hs < 5 m Piling: Hs < 3-4 m Lowering: Hs < 1.5 m (splash zone and slamming) Mooring: Hs < 3 m (floating wind turbine) Turbine single-unit installation: wind@10m < 8 m/s



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Weather window Restricted operation

T < 72 hours

Duration of operation Unrestricted operation T > 72 hours

(depending to T, DNV)

Credit: Finn Gunnar Nielsen

Weather forecasting, to find the proper window. www.cesos.ntnu.no www.cesos.ntnu.no


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Weather window

March-September

Installation of wind turbine (usually) restricted-operation However, 50-100 units installed Less sensitive, cost-effective and robust methods are required. www.cesos.ntnu.no www.cesos.ntnu.no


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Offshore wind power



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Bottom-fixed offshore turbines

Monopile · Steel tube, 4-6 m in diameter, · Installed using driving and/or drilling method, · Transition piece grouted onto top of pile Simple, Depth 3-20 m, No anchorage pile, Steel

Attractive foundation in shallow waters and smooth seas: Utgrunden, SE, Blyth, UK, Horns Rev, DK, North Hoyle, UK, Scroby Sands, UK, Arklow, Ireland, Barrow, UK, Kentish Flats, UK

Sensitive to scour, Soil characteristic is important, impractical in rocky sea-bottom

Easy to transport by floaters

www.wind-energy-the-facts.org



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Bottom-fixed offshore turbines Jacket · Made from steel tubes welded together, typically 0.5-1.5 m in diameter, · Anchored by driven or drilled piles, typically 0.8-2.5 m in diameter

Insensitive to scour 8-40 m depth small displacement at jacket top insensible to wave passage heave force

• • •

Complex anchorage pile in each leg needs protection against corrosion



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Bottom-fixed offshore turbines Tripod · Made from steel tubes welded together, typically 1.0-5.0 m in diameter, · Transition piece incorporated onto centre column, · Anchored by driven or drilled piles, typically 0.8-2.5 m in diameter

Insensitive to scour, 8-30 m, complex

Small tubs for legs and anchorage piles, Short anchorage piles

Crane barge or juke-up Small hammer for piling Drilling for stiff clays

Difficult to transport Field welding



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Bottom-fixed offshore turbines

Gravity base · Made from steel or concrete, · Relies on weight of structure to resist overturning,

Vindeby, DK, Tuno Knob, DK, Middlegrunden, DK, Nysted, DK, Lilgrund, SE, Thornton Bank, BE

extra weight can be added in the form of ballast in the base,

· Seabed may need some careful preparation, · Subjected to scour

Insensitive to soil parameters, depth 3-15 m, Poorly under scouring, complex configuration, heave force during wave passage, Large use of concrete, Close to wind farm site, strong lifting,



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Floating offshore turbines Cost effective solutions for moderate-deep water (i.e. depth>100 m)

Different concepts, innovative, hybrid, …



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Today-installation Denmark, UK, Netherland (Monopile and Gravity base)



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Marine operation for a wind farm

•Cable-laying •Foundation installation •Substation installation •Sea-based support •Turbine installation

Published on behalf of The Crown Estate www.cesos.ntnu.no www.cesos.ntnu.no


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Marine operation for a wind farm, cont.

Published on behalf of The Crown Estate www.cesos.ntnu.no www.cesos.ntnu.no


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Export cable-laying

connecting the onshore and offshore substations. as long sections as possible, up to 70km in length

Array cable-laying Cable-laying vessel Dynamically positioned vessel or barge.

between the turbines and the offshore substation. High pressure jetting Cutting systems to trench in clay or rock.

Trenching ROV



22 Cable laying (several days) Loading, Special vessel? To have the enough-capacity



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Foundation installation vessels

Self-propelled jack-up vessels, towed jack-up barges, floating sheerleg, catamaran cranes Self-propelled jack-up (e.g MPI Resolution). 140m X 45m wide, with a 6m draft and speed up to 11 knots. Jack-up legs allow operation in depths of up to 40m. (monopile) Floating cranes (e.g. Samson, Rambiz and Stanislav Yudin) for jacket, tripod and GBS. Onboard tooling: Hammer and anvil systems to drive the piles. Drilling systems, grouted into position. Positioning and upending tool to lift, rotate and lower the pile on the sea bed.

A handling tool is used for guiding during driving. Crane capacity around 1,000-3,000 tones.



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e.g. Scour protection of wind turbines.

Monopile installation fast installation

Piling equipment (Drilling) Pile lifting Field splice and adjustment to inclination Field welding Scour protection (static or dynamic scour protection) Monopiles: driven from a jack-up vessel but can be drilled/installed using floating vessel. driving (piling hammer), drilling, vibration

Pile driving at Offshore Wind Farm Egmond aan Zee www.cesos.ntnu.no www.cesos.ntnu.no


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Pile driving Driving using vibrators Not very large shock waves, No damage of adjacent structures.

Very little noise, urban areas Not been applied for offshore wind turbines. Environmental friendly (mammals, fish,…) Drilling or excavation Hard soils, Generating a hole with a diameter slightly larger than that of the pile. Grout may be injected in the annulus between the pile surface and the soil.

Drilling equipment at Blyth

suction bucket monopile (MBD)

accessories can be pre-attached. Also, the flange to which the turbine connected. So, no need for a transition piece, reducing the number of offshore operations.

Simpler installation as foundation towed-out No piling Less scour protection required www.cesos.ntnu.no www.cesos.ntnu.no


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Jacket installation

Oil and gas experiences, Drilling in boulder (very stiff clays) Difficult to transport Field welding for pile connections

Crane barge or juke-up Small hammer for piling

Beatrice, UK, www.cesos.ntnu.no www.cesos.ntnu.no


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Jacket installation

NorWind-Alpha Ventus

• Load-out, transport and installation of Jacket (Quattro-pods) wind turbines Pile transport and installation Jacket installation and grouting



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Tripod Similar to Jackets

Alpha Ventus



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Gravity foundation installation

Sea-bed preparation, Ballast placement (costly) Barge with big lifting capacity Tonnage barge adequate Large protection against scour

Weigh (i.e. 3,000 tonnes) and floated-out to position before being sunk. The sea-bed must be leveled.

Install smoothly! Water damps the motion Rambiz with gravity based foundation www.cesos.ntnu.no www.cesos.ntnu.no


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Substation installation Heavy lift (>1,000 tones), floating crane.

The substation is floated out of port on a barge (equipped with a heavy lift crane/ a separate vessel lift).

Sea-based support Crew vessels, anchor handling, barges, dive support, ROV handling. Crew vessels: typically 15-20m catamarans. ROV- and Dive-support vessels: 80-100m DP vessels with a moon pool and deck crane. www.cesos.ntnu.no www.cesos.ntnu.no


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Turbine installation ¾assembly of turbine tower, nacelle and blades at sea ¾transfer of complete turbines from land (demonstration projects). Round 1 and 2 (UK), towers mounted vertically on the vessel and one or more blades joined before shipment. Transportation of fully constructed turbines to minimize the time and work content at sea. OWEC Jacket Foundation at Beatrice Offshore Wind Project

Crane vessel “Ocean Hanne” used for turbine transport and installation



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Assembly at sea

Transition piece

Sits on top of pile, provide a flange for the connection of the turbine tower: •correct any misalignment of the foundation •hold the accessories (boat landing, J-tube, ladder and anodes) Connected to the foundation: using grout, a flange or a slip joint.

Lifting of a tower section for installation Turbine tower installed in 2-3 sections (bolted together). Connection between the transition piece and the turbine tower by bolting two flanges together.



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Shipping and assembly at sea



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Rotor–Nacelle assembly

The rotor-nacelle assembly can be installed either separately or using the Bunny–Ear method Rotor as one-piece

Bunny–Ear method

Separate



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Rotor as one-piece



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Bunny–Ear method



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Custom-made installation vessels Few of vessels being used for turbine installation were built for the purpose.

As market develops, innovative solutions with purpose-built vessels typical specification for such a vessel: Length: 130m, Beam 38m, Draft 5m Crane: 1000 tonnes Tonnage: 9,300 tonnes Speed: 11 knots Jack-up depth: 35m No. of wind turbines capacity: 6 No. of jack up legs: 4- 6 Jack up speed: 1m/min Dynamic positioning system


Components On-board crane. Dynamic positioning. Propulsion systems. Jack-up system. Specialized turbine transport and installation frames.


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Beatrice demonstrator project



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Sheringham Shoal Offshore Wind Farm, UK

Output: 315 MW Offshore Installation Start: 2010 Start Installation of Turbines: 2011 Project Completion: 2011

www.scira.co.uk

88 wind turbines, capacity of 3.6 MW Turbine Blade Length: 52m Turbine tower height: 80m

Contractor (MT Højgaard) use the “Svanen”, self-powered heavy-duty floating crane, to drive foundation piles 23-37m and mount transition pieces. two 1000 tone offshore substations StatoilHydro and Statkraft



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"Toisa Sonata" ready to leave Vlissingen with a monopile and transition piece.



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HLV Svanen

The Svanen and Toisa Sonata on the Sheringham Shoal site www.cesos.ntnu.no www.cesos.ntnu.no


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10 km west of Karmøy, Norway, at a depth of about 200 m



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Hywind (Marine Operations) Siemens and StatoilHydro

• Load-out and tow of Substructure • Inshore assembly • Installation of Permanent Mooring System • Tow-out and Hook-up of FWT • Installation of Subsea Cable



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Lead-out and Float-off at Technip yard, at Finland Wet-tow transport from Finland to Norway

FOTO: JON INGEMUNDSEN / STAVANGER AFTENBLAD

Wet tow from Finland, inshore mooring and barge support. Tow-out and offshore hook up. www.cesos.ntnu.no www.cesos.ntnu.no

Buksér og Berging AS


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Upending of spar

Ballasting



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Floating crane



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Vessel transportation of Siemens equipment (from Denmark to Norway), Assembling Siemens equipment at site,

Assembling: top sections, nacelle, hub with blades



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Offshore hook-up of mooring

Installation of Subsea Cable



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Spar-type installation Water depth!

In Norway, USA, Japan, … assembled and up-righted inshore and towed to its offshore location in vertical position. where the water close to the shore is shallow? Alternatively: Assemble at offshore-site For TLPs: ballasting and de-ballasting Sensitive to weather and instability during installation Tow-out on buoyancy modules until connection (Blue-H)

Sway (Tension leg spar-type turbine) Dedicated vessel tow-out and upending



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Assembled wind turbine installation

Sea Transport of Upright Wind Turbines! Assembled full-WT on a barge @ DTU

accelerations at the nacelle are selected as limit for transport Weather window for transport up to: Hs = 5 m, V=15 m/sec Stability and wave-induced motions

Glosten design TLP for shallower waters

sed Gifford/BMT/Freyssinet gravity based


SPT Offshore & Wood Group tri-bucket


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Semisubmersible installation

Port assembly No specialized vessels (conventional tugs) Tow-out fully commissioned (with turbine system) WindSea Project

Using semisubmersible to transport and install an assembled FWT?

Aquilo, UMB WindFloat Project



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New ideas to install spar-type FLIP (U.S. Navy)

Challenge: loads on the turbine! FLS, fatigue contribution, ULS, risk assessment is it possible for Sway concept?


Transport and install full assembled FWT Madjid –01.03.2011 Author – Centre for Ships andKarimirad Ocean Structures

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Conclusion

Cost



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Conclusion

New trend: large wind farms with a capacity of hundreds of MW. With the increasing number per year, there is a need for new equipment. Lack of availability of vessels Large projects are stretched over more seasons For few months weather conditions are appropriate (70% of the days in a year) Complete installation procedure of an offshore wind farm requires different individual steps, from turbine manufacturing to the start of operations.

To reduce the resulting cumulated risk of the offshore wind energy, ameliorate the installation process uncertainties.

Two seasons for foundation/turbine installations resulted in buffer time for project completion.



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Conclusion Limited number of vessels available and few companies with the expertise.

Different installation vessels are necessary to install turbines in shallow and deep water. Installation of groups of wind turbines? Other strategies, especially in deeper waters, innovation to reduce costs. Season for installation is extended. Optimize design process by seeing the entire structure as one. Transporting WT completely assembled to the offshore site. Improve the installation procedure = cost reduction Less sensitive to the weather conditions Effective and robust installation methods Offshore wind industry is often dominated by players with background in onshore. Adapting rules/recommended to the offshore wind industry requirements. (Optimizing cost and necessary safety margins) www.cesos.ntnu.no www.cesos.ntnu.no


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Acknowledgement: T. Moan, Z. Gao, G. R. Gunnu, A. R. Nejad, A. Natskår, Å. Eika

Combined FWT and WEC Wind and wave

Floating Power Plant A/S

Poseidon platform, Denmark

Thanks for your attention www.cesos.ntnu.no www.cesos.ntnu.no
