Offshore Wind Presentation

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IEEE Boston PES - November 16, 2010

Offshore Wind


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Offshore Wind

A h igh-leve l overv iew of o f fshore w ind pro jec t

deve lopm ent ident i f ying cur rent t ec hno log ies ,

c ha l lenges, r isk s and c ost s .

Presented by: Brook KnodelElectrical Group Manager, Mott MacDonald LLC

[email protected]


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Discussion Outline

Industry Overview

Components Turbines/Foundations

33 kV Collector System (Inter-Array Cables)

Offshore and Onshore Substations HV Submarine Cable

Risks and Obstacles

Costs

Questions


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Industry OverviewWind turbine technology hasproven to be one of the mosteffective sources of renewableenergy. By the end of 2009

worldwide capacity reached 159GW, generating 340 TWhannually.

Offshore wind offers manyperformance benefits versusonshore wind generationincluding strong, steady windsand proximity to metropolitancenters.

Source: WWEA World Wind Energy Report 2009


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Industry Overview cont.

Over 3 GW of offshore wind installed globally

Mainly Europe and UK

Roughly 2 GW currently in construction

Growth has been exponential with 32 GW targeted for theUK by 2020 and 30 GW for Germany by 2030

Ability to meet these targets limited by several factors

Technology

Supply Chain Construction Capacity


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Industry Overview cont.

In North America, several developers are proposingoffshore wind along the North Atlantic Coast and Great

Lakes. Deepwater Wind, Fishermans, Bluewater Wind/NRG, Cape Wind

Trillium, Great Lakes Offshore Wind, Windstream Energy

Developers are jumping into large scale 500 MW+ projects

Progress has been slowed due to many factors:

Financing, permitting (land rights/BOEMRE), supply chain,infrastructure, regulatory, lack of long-term federal guidance


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ComponentsOffshore wind farms have many similarities to their onshorecounterparts but the marine environment poses uniquetechnical design challenges.

Major components of an offshore wind farm include:

Turbines

Foundations

Inter-Array Cables

Offshore Platform Substation/High Voltage Export Cable

Interconnection Facilities


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Components cont.


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Components cont.


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Components cont.


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Components cont.


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Components cont.


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Thornton Bank Phase I, BelgiumREpower 5 MW turbines (30 MW)

Components - Turbines


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Turbines cont.

Typical types

High-Speed Multi-Stage Gearbox (Vestas)

Direct Drive PM/Converter (GE, Siemens, Vestas)

Multibrid Low-Speed Gearbox (AREVA, REpower)

Projects in development now will probably utilize 5+ MWturbines as the technology continues to develop

Costs average $2.5M per MW (not installed)

Factories are fully booked for the next few years and globalcapacity is not sufficient for even a small subset of theproposed projects currently in development.


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Thornton Bank Phase I, BelgiumFoundations

Components - Foundations


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Foundations cont.

Types

Monopile (most popular type)

Gravity Foundation (previous slide - 10 stories high, 3000 tons!)

Jackets (inexpensive and most suitable for deep water projects)

Tripods (specialty for some turbine manufacturers)

Floating? (currently being developed)

Past projects were in shallow waters (60 ft) and currentprojects are in 100 ft depths. Future projects are plannedfor much greater depths which will create installationchallenges.


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Foundations jackets and mono-piles


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Foundations tripods and gravity type


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Foundations cont.

Currently the foundations and turbines are erected usinglarge jack-up barges customized for turbine erection. The

depth of water is a limiting factor and alternate means oferection are being investigated for future deep waterprojects.

The east coast has relatively shallow depths along thecontinental shelf, but current US jack-up barges may not besuitable.

Foundation selection is very dependent upon subsurface

conditions. In-depth marine geotech studies are essential.

Costs range from $2.5M to $4M each (not installed)


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Inter-Array Cables cont.

Utilize solid-dielectric 36 kV insulation offshore generatorvendors provide a standard 33 kV primary on each

generator step-up transformer. Optical fiber integrated forcommunications.

Each cable can collect up to 35 MW of generation. Larger

projects require offshore consolidation of multiple feeders. Installed costs are a small portion of the project, but

Installation has proven a challenge (over 80% of insurance

claims $$ for offshore wind are related to the inter-arraycabling). Many installation contractors have gone bankrupt.


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Barrow Offshore Wind Farm, East Irish Sea, UKOffshore High Voltage Substation Platform

Components Offshore Substation

Platform/High Voltage Export Cable


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Offshore Platform/Export Cable cont.

Necessary for projects larger than 35 MW to consolidateinter-array cable feeders and step voltage up to suitable

transmission levels Design Considerations:

Weight and real estate are restrictive. Gas insulated designs (GIS)

are utilized for 33 kV and High Voltage AC switchgear. Location of the platform is selected to optimize cost of inter-array

and export cable installation

For projects larger than 200 MW multiple platforms may bepreferable/necessary.


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Export cables are solid dielectric XLPE. Not much trackrecord above 245 kV.

Long distance submarine cables have high losses and cangenerate significant VARs necessitating reactors to controlpower factor.

Splices are potential weaknesses so preference is acontinuous cable per phase from shore to platform.


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Routing of the export cables requires significant planning.

Cable crossings need to be coordinated with the affected party.

Existing cables need to be physically protected and crossings needto be perpendicular. Negotiations may impact schedule.

Subsurface investigations may show obstacles that need to beavoided (shipwrecks).

Closer in to shore, human, fish, plant and animal habitats mayrestrict access. Typically the shore landing requires directionaldrilling or sawing. There are heavy duty saws available but theycost $2M to mobilize, $0.1M per day to operate and another $2M to

demobilize.


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As projects get larger and further offshore, new voltage sourceconverter HVDC technology is being considered.

Standard HVDC converter technology is too space intensive to fit onan offshore platform. VSC converter technology, such as ABBs

HVDC Light, can be configured to fit and provides significant benefitsat the point of interconnection including enhanced voltage/VARsupport, black start capability and minimal short circuit contribution.

Many countries (including the UK, Europe and the United States) arelooking into developing offshore HVDC backbones for interconnectionof renewable energy and strengthening of regional transmission

networks.

Current designs accommodate up to 1200 MW per +/-320 kVdcconverter although these technologies are new and have not been incommercial operation. (400 MW offshore has been operational)

Installing HVDC requires an onshore converter station which can becostly in densely populated regions such as New York City.

Lack of HVDC circuit breakers make multi-terminal designs achallenge. Temporary solutions utilize AC CBs as switches.

Costs on order of $1M per MW installed (including submarine cable)


Source: ABB It is Time to Connect


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Export cable and HVDC technologies represent a lot of riskfor the currently proposed projects over 500 MW. There is

little or no track record for the submarine cable andconverter equipment although many major manufacturersare focusing on bringing these technologies to market.


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NYPAs Ryan Substation, New York230 kV Substation

Components Interconnection Facilities


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Interconnection Facilities cont.

In much of Europe, utilities are required to bring the point ofinterconnection to the offshore platform. In the United

States, the export cable and substation upgrades requiredto support the project are the responsibility of thedeveloper.

Details are defined by the interconnection studiesconducted by the regions Independent System Operator incoordination with the interconnecting transmission owner.

Costs vary widely based on voltage and the areas ability toaccommodate the proposed plant output.


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Risks and Obstacles cont.

How will you finance it? (Multibillion dollar projects)

Who will buy the electricity? (FIT, PPA)

What ships will you use? (Jones Act, St Lawrence Seaway) What labor force? (Jones Act)

Where are you going to stage the construction? (Ports)

Will your technology survive the conditions?

Will political support remain in place? (Federal, State)

Will the weather impact your schedule?

How will you maintain it?


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CostsCompared to onshore wind, offshorewind costs approximately threetimes as much to install. Theseincreased costs are partially offset

by increased efficiency due tosteady winds and closer access tometropolitan areas along the coast.

Land based wind projects typically

require $1.5M per MW investment.Offshore wind costs have beenincreasing over time as the projectsmove from shallow coastal waters todeeper regions. Current investment

projections vary from $3M to $5Mper MW.


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Comparative generating costs, base

case 2009 start

Discounted lifetime cost / productionMid 2010 datum


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Costs cont.

A typical breakdown of the costs associated with large-scale offshore wind:

Development 2.5%

Permitting, Legal Fees, Preliminary Design, Interconnection Studies, Site Investigation,Land Acquisition

Turbine Procurement 40 %

Foundation Procurement 10 %

Other Supply Costs 7.5 %

Platforms, Cables, Substation Equipment

Installation and Erection 15 %

Other Costs 25 %

Owner Management Costs, Contingencies, Bank Fees, Insurance, Interest


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Costs cont.

Operation and maintenance costs are difficult to project forUS projects. Vendors are not regional and there are no

experienced ships or crews in existence. O&M Costs, based on what is being done in Europe are

$150k - $200k per MW depending on distance from shore

and contract conditions. This equates to approximately $0.05 per kWh for O&M

alone.


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Questions?


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