20 January 2009 I Mech E Manchester Marine Current Turbines TM Ltd Coastal Marine Power and the Role of Marine Current Turbine’s technology

by Peter Fraenkel, BSc(Eng), CEng, FIMechE, FIE Technical Director

Marine Current Turbines Ltd The Court, The Green, SkGiffdBilBSStoke Gifford, Bristol BS34 8PD, UK . www.marineturbines.com 1 Marine Current Turbines TM Ltd

Climate change - CO2 last 1000 years

Start of industrial revolution

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Peak Oil - the Supply-Demand Gap

Source: Dick Lawrence, The Case for Modeling World Energy Flow, World Energy Modelling, Berlin 2004

BB

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80 ? gap World Conservation ? Renewables ? 60 Lifestyle change ? Substitution ? Deprivation ? Conflict ? 40 OPEC

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USA 0

1920 1940 1960 1980 2000 2020 2040 3 Marine Current Turbines TM Ltd

Most renewables are diffuse

Source: Prof. David MacKay Without the Hot air 2008 4 Marine Current Turbines TM Ltd

Marine Energy - the options

Technology Status Load Installed Unit cost Size of UK factor Capital cost electricity resource (%) (£/kW) (p/kWh) (TWh/yr) Offshore wind commercial 25 to 40% 1300 – 2000 5 to 7p over 100 ☯☯ Tidal barrage uneconomical 20 to 25% 1500 - 3000 >9p ~50 ☯ Tidal & marine current pilot projects 30 to 45% 1500 - 2500 3 to 9p * >20 ? turbines ☯ Wave – shoreline OWC experimental 20 to 30% 1500 - 3000 5 to 10p ~2 Wave - nearshore OWC experimental 25 to 35% 1500 - 3000 5 to 12p ~50 ☯? Wave - offshore – point pilot projects 20 to 50% 1500 - 2500 ? 4 to 12p * >100 or line absorber or ☯? OWC OTEC experimental 80% + ? ? ? n/a to UK Salt gradient laboratory 80% + ? ? ? ? ? * Carbon Trust “Future Marine Energy: The Results of the Marine Energy Challenge”, Jan 2006 figures apply for 1GW installed

Highlighted rows show technologies most likely to be cost-effective for use off the UK Marine Current Turbines TM Ltd Wind - the big one for the UK?

23,000 offshore 5MW widtbiind turbines wou lddlild deliver on average more than the entire present UK domestic electricity demand Marine Current Turbines TM Ltd

UK Offshore Wind

Gross usable Sea-Space = 76,000km2 Typical power capture = 3MW/km2 Gross energy capture = 3,200 TWh/yr DTI projection (2002) = 100 TWh/yr implies th e gov ernm en t onl y ex pects to use 3% of gross at approx 7GW A total of approx 390TWh of eltiitlectricity was genera tdithUKted in the UK in 2004. Marine Current Turbines TM Ltd

La Rance Barrage the exception that proves the rule the only large tidal barrage in the world Rance River estuary, Brittany (France) 24×10 MW bulb turbines (240 MW) Built 1966

http://www.stacey.peak-media.co.uk/Brittany2003/Rance/Rance.htm Marine Current Turbines TM Ltd

Severn Barrage - coming up for its 4th review

• Severn River estuary • 8,640 MW total capacity • 17 TWh average energy output • Ebb generation with flow pumping • 16 km (9.6 mi) total barrage length • £14 billion estimated cost • 27% Capacity Factor (2 x 4hr in 24hr) unlikely to be economically competitive Marine Current Turbines TM Ltd

Comparison: Severn tidal barrage v tidal stream Marine Current Turbines TM Ltd

Severn Barrage - coming up for its 4th review

Proposed Cardiff Weston Barrage silt Marine Current Turbines TM Ltd

Excellent Reference Marine Current Turbines TM Ltd

What could be possible Marine Current Turbines TM Ltd

Where we seem to be heading? Marine Current Turbines TM Ltd

State Sector Energy R&D spending 1974-2005

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Structural: the reaction to power generation

~100t per MW at 2.5m/s ~170t per MW at 1.5m/s Marine Current Turbines TM Ltd

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

… fthldlfew technology developers are anywhere near to delivering technology to fit these criteria

* i.e. wave and tidal stream energy systems 17 TM Marine Current TurbinesWave Ltd Energy UK Resource water depth mean power annual (()m) (GW) energy (TWh) 40 10 87 20 7 61 shoreline 0.2 1.75 Marine Current Turbines TM Ltd

Shoreline Wave Energy Converters: ’s Limpet Oscillating Water Column Marine Current Turbines TM Ltd

Near-shore - Aquamarine “Oyster” Marine Current Turbines TM Ltd

Pelamis

Pitching segments react against each other - hydraulic rams drive hydraulic motor and hence an electrical generator Marine Current Turbines TM Ltd

Ocean Power Technology - 40kW Powerbuoy

Heaving buoy with internal reaction Marine Current Turbines TM Ltd

Wave Dragon - overtopping wave collector Marine Current Turbines TM Ltd Tidal Stream Energy

1. Large resource - too big to be neglected or ignored 2. Technical feasibility - rapid development is possible 3. Predictability - driven by gravity - not weather 4. Minimal environmental impact - and favourable ERoEI - <12mths San Bernardino Straits - The Philippines

shown running at 3.5m/s or 7 knots 24 Marine Current Turbines TM Ltd

Marine currents = High energy intensity A tidal current turbine gains over 4x as much energy per Size Comparison 2 m of rotor as a wind turbine 1MW wind turbine compared with 1MW tidal turbine 1 x 55m dia

Outline of 1MW solar array 70m x 70m

2 x 16m dia

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The Effect of Velocity Shear

Velocity Power / Energy Sea Level

75% of the Energy is in the upper 50% of the water column

25% of the Energy is in the lower 50%

Sea Bed Marine Current Turbines TM Ltd Hammerfest Strøm 300kW - (2003 - ?)

Hammerfest Strøm 300kW axial flow ((y)Norway) Marine Current Turbines TM Ltd Ponte di Archimede “Kobold” Turbine - (2004) - 20kW Marine Current Turbines TM Ltd North American experimental devices

UEK - 30kW?

Verdant Power (35kW) (6 units in East River NY) Marine Current Turbines TM Ltd Recent experimental devices in 2007

Open Hydro - 50kW?

Clean Current - 50 to 100kW? Marine Current Turbines TM Ltd Marine Current Turbines: SeaGen

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MCT responsible for 3 out of 5 tidal turbines tested so far in the UK

at least 300m2 rotor area needed for economic viability because of high fixed cost overheads of off-shore projects MCT MCT MCT

2 10m 150m2 95m2 28m2 402m2

note that SeaGen is the first large enough for commercial viability - 4x the size of even Seaflow 32 rotor area TM sq.m. Marine Current Turbines Ltd 410 400 390 380 370 360 350 340 330 Square metres of 320 310 300 sq.m. gives about 1000kW at 2.5m/s 300 290 nominal minimum size for commercial scale generation tidal turbines in the 280 270 260 sea so far…. 250 240 230 220 210 200 190 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 Rotor Area 10 24 95 113 28 20 28 28 48 28 402 sq.m. Rotor Size 3.5 2 x 4 11 12 6 5 6 6 4 x 12 6 2 x 16 metres

f t i t K w r o s n n o p m d e r n u o e f e E lo e e d e e l c U f o w r r o G o r m o y r a o n a t i H u e S r o e h P N e P S S c t n c R S C t r n T s e n R A T T A a p a A C C fe i d e C r d r O l M M e e C M e m t V n m o a P H Date 1994 2002 2003 2003 2004 2006 2006 2006 2007 2008 2008 Marine Current Turbines TM Ltd

Background: 15kW Tidal Current Turbine (1994-5) PROOF OF CONCEPT PROJECT (IT Power. Scottish Nuclear & NEL) Loch Linnhe, World’s first tidal current turbine

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Seaflow installed operational rotor raised for access 30 May 2003 rotor dia. 11m (= 95 sq.m.) rated power 300kW @ 2.5m/s pile dia. 2. 1m mass 130t water depth 24m ± 5m

Low cost access from a RIB

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SeaGen Prototype Some key features:- 2 x 600kW rotors:16m diameter

rotors and nacelles raised above sea level for maintenance and easy replacement transformer and electrical connection to grid in accessible and visible housing at top of pile 180 degree pitch control allows efficient rotor operation w ith bi- directional flow

deployment in arrays or “ farms”. of hundreds of turbines 36 Marine Current Turbines TM Ltd

Seagen: Performance at Lynmouth & Strangford Marine Current Turbines TM Ltd

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SeaGen - 600kW hub, gearbox and generator

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Speed-increasing gearbox

8 planet wheels to cope with torque Marine Current Turbines TM Ltd

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

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SeaGen 1.2MW Commercial Demonstrator - installed in Strangford Narrows, NI

- to be used as testbed for SeaGen technology

- will have continuous environmental monitoring

- mean max current 9kt water depth 25m ± 2m

- but structural change from monopile as shown to jacket 42 Marine Current Turbines TM Ltd

Seacore Jackup-rig Excalibur visits Strangford 16-19 April 2005, to complete SeaGen geotechnical survey - original plan was to use Excalibur for monopile installation but in the end no jack-up barge proved to be available

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Plan ‘B’ - Jacket Foundation Unable to obtain use of Jack-up Barge within sensible time frame

Therefore MCT team worked fast to convert monopile structure to new self-installing Quadrapod - from concepttt to i nst all lltiation in bare ly s ix months

This is designed to be drilled into place from temporary platform and can be positioned from a Crane Barge

Pinned to seabed with 1m diameter steel piles, 9m embedment Marine Current Turbines TM Ltd

IidInside SeaGen…

5 levels containing…

power conditioning 11kV transformers control systems safety systems hydraulic lift mechanisms cooling & climate-control Marine Current Turbines TM Ltd

SeaGen showing quadropod (4 feet) jacket structure beinggy collected by crane barge “Rambiz” at Harl an d & W olff , Belfast

ballasted to over 1000 tonne note temp drill platform Marine Current Turbines TM Ltd

Positioning operation Marine Current Turbines TM Ltd

SeaGen is lowered to the seabed 04:35hrs 2 April 2008 Marine Current Turbines TM Ltd

Construction Barge in Position alongside SeaGen -note drilling platform with two conductor tubes in place SeaGen structure ballasted to stay in place during drilling Marine Current Turbines TM Ltd

Drilling and Grouting Operations - carried out from temporary work platform Marine Current Turbines TM Ltd

SeaGen: installation completed 15 May 2008 Marine Current Turbines TM Ltd

SeaGen commissioning in progress note - this shows rotors raised at slack tide Notes: 1. Safe access to these technologies is vital - nothing is 100% reliable 2. The UK Maritime & Coastguard Agency seems happier with a well-marked surface-piercing structure than something that is submerged and invisible Marine Current Turbines TM Ltd

SeaGen commissioning

Tide races are dangerous places but safe access is vital - no system is 100% reliable Marine CurrentSeaGen Turbines TM Ltd note - this shows rotors raised at about 1. 5-2m/s flow

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SeaGen

note - this shows typical flow at over 3m/s Marine Current Turbines TM Ltd

SeaGen

Cross arm being raised with strong current flow as viewed from superstructure Safety boat “running to stand still” Without pitch controlled rotors this would not be possible Marine Current Turbines TM Ltd

SeaGen maintenance

Most maintenance and repair functions can be completed rappy,idly, usin g no more than small service vessels Here: fitting a new rotor blade Marine Current Turbines TM Ltd

SeaGen delivers …. full power 14 Oct 08

620kW power

generator speed

1000rpm

1300hr 1400hr 1500hr 1600hr Marine Current Turbines TM Ltd

SeaGen delivers …. full power December 08 Marine Current Turbines TM Ltd

Potential Tidal Current Energy Sites (Irish Sea)

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

This is a computer generatdted mo dldel o fthf the entire Irish Sea tidal flow N.I. Belfast regime at Spring Tide, 3hftHWBlfthrs after HW Belfast Strangford

However only areas shown in magenta (and ringed in blue) have enough energy to be useful image courtesy Kirk McClure Morton

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Next stage - 10 MW SeaGen Array - Anglesey Skerries - Wales project planned for 2010-11 - MCT & RWE renewables

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Costs of projects (GB £) and main sources of finance Proof ofof Joint ppjroject ~ £0.35M Concept IT Power ~ £0.50M 1992-1995 Scottish Nuclear ~ £0.25M NEL ~ £0 .50 M Seaflow Consortium project~ £3.4M

1998-2006 European Commission Commission ~£08M~ £0 .8M UK Government (DTI) ~ £1.3M MCT & partners ~ £1.3M SeaGen MCT projectproject ~ £20.5M 2003-2009 UK Government (DTI) ~ £5.2M EDF Energy ~ £1.0M Marine C£Current Turbines ~ £1314.3M SeaGen Array Consortium Project~ £52M

2008-2011 MCT, RWERWE npower npower renewables renewables + + possible further investors

Marine Current Turbines TM Ltd

Driving down costs Note 1p = £0.01 ≅ Euro 1.5c

Severn Barrage at 8% discoun t rate - if built to budget! ?

2005 2006 2007 2008 2009 2010 2011 2012

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Environmental Issues Marine Current Turbines TM Ltd

Principal Environmental Issues - tidal stream

Pollution (water quality): lubricant (~1m3), anti-fouling (zero), electromagnetic fields (~1m from cable) NtNatura lprocesses: possible disturbance of seabed, changes to sedimentation Marine fauna &/or flora: possible effects on benthos, fish, marine mammals diving birds and marine flora Human activities: marine traffic/navigation, fishing, drift diving, tourism, local trade Cultural Heritage and landscape: vilisual impact - posiiitive and negative Climate Change rapid changes, sea level rise, possible ending of Gulf Stream, marine pH changing, extreme storms, etc Marine Current Turbines TM Ltd Marine Mammals - Seals

Tagging Antenna 12 animals Pre-installation Post installation

Courtesy SMRU St Andrews 66 Marine Current Turbines TM Ltd

Common Seal tracking telemetry by SMRU

-6 ° -6 ° -6 ° -6 ° -5 ° -5 ° -5 ° -5 ° -4 ° -4 ° 5... 5... 5... 5... 6°00' W 5°40' W 5°30' W 5... 5...

5°40' W 5°30' W 5... 5... °10' N °10' °10' N °10' 44 44 5 5 5... 5... 5... 5... 54°30' N 54°30' N 54°30'

Lines : gps.ref 5... gp4_GSM103_06 5... gp4_GSM106_06

gp4_GSM108_06 gp4_GSM152_06 gp4_GSM157_06 gp4_GSM330_06 gp4_GSM333_06 5... gp4_GSM446_06 5... gp4_GSM669_06 gp4_GSM948_06 54°00' N 54°00' gp4_GSM979_06 N 54°00' gp4_GSM981_06

Points 5... GSSHS_UK 5... 0 100 km Areas

-6 ° -6 ° -6 ° -6 ° -5 ° -5 ° -5 ° -5 ° -4 ° -4 ° 0

6°00' W 5°40' W 5°30' W gp4_GSM157_06 male start 03 Apr last tx 14 Jul 0 5°40' W 5°30' W gp4_GSM948_06 female start 04 May Courtesy SMRU St Andrews last tx 17 Jun 67 Marine Current Turbines TM Ltd

Bird fatalities from wind turbines & other causes: ggggetting things into ppperspective

Prof. David MacKay

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Route towards Second Generation Technology

1. developpp a reliable power 2. Scale it up and down unit b ase d on S eagen within reasona ble li mit s

8m (26ft) 12m (39ft) 16m (52ft) 20m (65ft) 24m (76ft) 110kW 270kW 525kW 880kW 1,350kW

6 rotors of ---- 8m dia 12m dia 16m dia 20m dia 24m dia give rating of --- 0.66MW 1.6MW 3.1MW 5.3MW 8.1MW

3. Deploy suitably sized array of rotors across current

…. but we need to develop a suitable structure to hold them Marine Current Turbines TM Ltd

MCT 2nd Generation - patented horizontal array structure - operates wholly submerged but with self surfacing capability to facilitate safe access

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Second Generation - horizontal array structure Marine Current Turbines TM Ltd

Progress as planned by MCT - bigger and better

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Marine Current Turbines Ltd http://www.marineturbines.com tel: (+ 44 or 0) 117 979 1888

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