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IWEA 3 October 2008

Tidal Power and the ‘SeaGen’ Tidal Stream Turbine

An Overview

by Martin WrightManaging Director

Marine Current Turbines Ltd The Court, The Green,

Stoke Gifford, Bristol BS34 8PD, UK.

www.marineturbines.com

Why use marine currents?

1. Predictability - driven by gravity - not weather

3. Minimal environmental impact - and favourable ERoEI - <8mths

4. Modular technology - short construction lead time

San Bernardino Straits - The Philippines

shown running at 3.5m/s or 7 knots

2. High Load Factor (works on both the ebb and the flood tides)

5. Technical feasibility - rapid development is possible

Why Do It?

■ Significant Comparative Advantage

Best Resource in Europe for Wind, Wave & Tidal

■ Strong Market Drivers

Peak Oil

Security of Supply

EU Directive 15% of ALL Energy

Climate Change

■ Leading Technologies

■ Industrial Assets

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Potential Tidal Current Energy Sites (Irish Sea)

Scotland

N.I.

Wales

Strangford

Analysis of tidal flows was difficult but new techniques are making it easier.

This is a computer generated model of the entire Irish Sea tidal flow regime at Spring Tide, 3hrs after HW Belfast

However only areas shown in magenta (and ringed in blue) have enough energy to be useful

image courtesy Kirk McClure Morton

Belfast

State of the Art = Tidal Stream Technology1. Systems of more than 100kW

Engineering Business (UK) Stingray - reciprocating hydrofoil 150kW2002

MCT (UK) – Seaflow single axial flow rotor 300kW2003

Hammerfest Stroem (Norway) - Blue Concept – single axial flow rotor 300kW2003

MCT (UK) – Seagen twin axial flow rotors 1.2MW2008

2. Systems of less than 100kW

MCT (IT Power / NEL / Scottish Nuclear) (UK) - single axial flow rotor 10kW1994

Florida Hydro / - unconventional ducted axial flow rotorOpen Hydro (Ireland)

35kW~75kW

20032007

Verdant Power (USA) - single axial flow rotor 35kW2005?

Ponte di Archimedi (Italy) - Kobold Turbine - single Darrieus rotor 25 kW2004

UEK (USA /Canada) - two ducted axial flow rotors 40kW?2002?

Clean Current (Canada) - single axial ducted flow rotor 80kW?2007

3. Systems with no more than small-scale physical models tested

SMD Hydrovision (UK) / TiDel - 1/10 model tank tested 1MW ?

Lunar Energy (UK) / R1000 or R1500 – ~1/20 model tank tested 1 MW?

Tidal Hydraulic Generators (UK) ~1kW model tested ? ?

Swan Turbines ~1 kW model tested 1MW ?

4. Systems with no more than theoretical design work completed

SSE/Weir / RTVL Neptune - proposed 2MW twin axial flow rotors 2MW ?

Tidal Generation - proposed 1 MW single axial flow rotor 1MW ?

Tidal Stream - proposed group of 4 axial flow rotors 2MW 2010?

plus 20+ others ……

abandoned

The Effect of Velocity Shear

Velocity Power / EnergySea Level

Sea Bed

75% of the Energy is

in the upper 50% of

the water column

State-of-the-art: comparison of rotor sizes

Note: the swept area of the rotors governs the energy capture at any given location

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Decentralised Marine RE Systems*:

What do we need for commercial success?

1. Scale – must be 1MW or more to be economic

2. Access – safe, affordable, reliable access for servicing

3. Reliability – need to minimise costly intervention

4. Life – several decades; otherwise not economic

… few technology developers are anywhere near to

delivering technology to fit these criteria

* i.e. wave and tidal stream energy systems

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Background: 15kW Tidal Current Turbine (1994-5)

PROOF OF CONCEPT PROJECT

(IT Power. Scottish Nuclear & NEL)

Loch Linnhe, Scotland

World’s first tidal current turbine

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Seaflow installed

30 May 2003rotor dia. 11m

rated power 300kW

pile dia. 2.1m

water depth 24m 5m

operational raised for access

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the basic concept

Axial flow rotor

Marinised drive train

Surface breaking monopile

Structural integrity

Low cost intervention

No significant environmental impact

Seaflow: What has ‘worked’

SeaGen Prototype Some key features:-

rotors and nacelles raised above

sea level for maintenance

2 x 600kW rotors:16m diameter

installed on steel pile

transformer and electrical

connection to grid in accessible

and visible housing at top of pile

deployment in arrays or “farms”.

of hundreds of turbines

Gearbox, hub and generator

Seagen: Performance at Lynmouth & Strangford

Rotor assembly at H&W - 16m diameter - 2 x 600kW

Assembly at H&W - cross arm (above) pile (below)

Seagen - complete and ready for installation

at Harland & Wolff, Belfast - March 2007

Revised Jacket Foundation

■ Retain existing SeaGen

structure above the Mud-line

■ Create new Quadrapod

foundation

■ Install using a Crane Barge

■ Pin to seabed with Ø1m steel

piles, 8m-10m embedment

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New Quadropod base for Seagen being fitted – Mar 2008

‘SeaGen’ arrives in Strangford Lough - April 2008

‘SeaGen’ positioned, ready for pinning to seabed

Construction Barge in Position

Drilling and Grouting Operations

SeaGen Raised

Marine Current Turbines Early Project Costs

Location RatedPower

(MW)

Capitalcost

(£k/MW)

Life CycleUnit cost

(p/kWh)

Strangford 1.2 5,191 16.8

Anglesey Skerries demo 10.5 2,537 11.7

Anglesey SkerriesCommercial

51.0 1,489 7.9

Anglesey Skerries ifdeveloped fully

(after 500MW installed)

30.0 923 5.2

Cost projections from due diligence report by Black & Veatch 2006/8 in an independent assessment

MCT Site Development Plan - Weighted Average Generation Cost

5.00

6.00

7.00

8.00

9.00

10.00

11.00

12.00

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Cost of MCT technology Cost of Offshore Wind

an indicator of cost-effectiveness

how many kWe per tonne of equipment?

Vestas V80 windturbine ~ 3.4 kWe per tonne

offshore at North Hoyle590t & 2000kWe

Wave energy devices << 1.0 kWe per tonne

MCT Seaflow tidal turbine ~ 2.3 kWe per tonne130t & 300kWe

MCT Seagen prototype ~ 3.1 kWe per tonne390t & 1200kWe

MCT 2nd Generation ~ 5.0 kWe per tonne1000t & 5000kWe

Commercialisation - The Next Stage

■ Requirements

Capital

Capability

Supply chain

Sites

Realistic and consistent market signals

Scotland and…………… the Rest….

Commercialisation - The Next Stage

■ The obstacles

Slow government progress - SEAs

Consents – Crown Estate

Unrealistic lease terms

Lack of Grid infrastructure

Competing for Capital……………??

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Marine Current Turbines Ltdhttp://www.marineturbines.com

tel: (+44 or 0) 117 979 1888