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Turning the Severn tide Liberal Democrat Conference Clydach 11th Oct 2008 Neil Crumpton Energy campaigner Friends of the Earth Cymru.

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Presentation on theme: "Turning the Severn tide Liberal Democrat Conference Clydach 11th Oct 2008 Neil Crumpton Energy campaigner Friends of the Earth Cymru."— Presentation transcript:

1 Turning the Severn tide Liberal Democrat Conference Clydach 11th Oct 2008 Neil Crumpton Energy campaigner Friends of the Earth Cymru

2 The Severn Estuary and its tributaries are protected under a range of national and international designations: three Site of Special Scientific Interest (SSSI) (Upper Severn Estuary, Bridgwater Bay and Severn Estuary). Wetland of International Importance (Ramsar) inter-tidal area protected as an SPA under the Wild Birds Directive - 6 protected bird species rivers Wye, Usk, are designated Special Area of Conservation (SAC’s), highest protection - migratory fish Natura 2000 network of sites of European importance for wildlife and habitats EU states required in law to protect them

3 Friends of the Earth Cymru Habitats & Birds Directives - legal requirement to demonstrate an : ‘overriding public need not achievable by other means’ SDC support for a Cardiff-Weston barrage triggered a study to check alternatives opportunity-spend of £15-23 billion on UK strategic energy infrastructure

4 Friends of the Earth Cymru Energy security and climate protection Severn tidal feaibility study - announced 22nd Jan ‘cross-Whitehall’ Phase 1 to Dec 08 - all projects screen for ministerial decision Phase 2 to 2010 - selected projects taken forward for detailed studies Final decision by government

5 Friends of the Earth Cymru Severn Tidal study - ‘runners and riders’ : Outer barrage : Minehead-Aberthaw Cardiff-Weston barrage (ebb/flow?) Middle barrage : Tom Shaw Shoots barrage Beechley barrage Tidal fence : Pulse Tidal Russell Lagoon : Fleming Energy Tidal lagoons : Tidal Electric Ltd Tidal reef : Evans Engineering Cardiff-Weston Causeway

6 Friends of the Earth Cymru Cardiff - Weston Severn Barrage An ‘ebb-only’ barrage would : impound 185 square miles - a lake 5 m deep submerge 60% (45 sq mls) of inter-tidal habitats - mud-flats, sand-flats halve tidal range and moderate the Bore - alter salt-marshes impede navigation to ports cost £15+ billion (without the road or rail)

7 Friends of the Earth Cymru Cardiff- Weston ‘Severn’ barrage * would generate 17 Tera-watt hours per year about 4.4 % of current UK electricity demand electricity demand is about 20 % of UK energy ~ 1% of current UK energy demand ~ 1.4 % of 2050 UK energy demand ‘ebb-only’ not ‘ebb & flow’ ?

8 Friends of the Earth Cymru

9 Navigation to Port of Bristol barrage would reduce spring tide height by around 1 metre (+ sedimentation ?) reduced draught for largest container ships to Bristol ports proposed port expansion - barrage ‘blight’ knock-on land transport issues if Felixstowe or Southampton if shipping diverts

10 Friends of the Earth Cymru

11 Barrage output - predictably problematic : barrage output swing 1.5 GW - 8 GW per hour - possibly 170 times a year during the morning ‘switch on’ and evening winter peaks UK electricity grid demand can rise by 5 GW per hour 35 GW of windfarms (6 x more output than barrage pa) likely swing 1 GW per hour, 7 GW per hour about once a year

12 Friends of the Earth Cymru Tidal stream - Seagen

13 Friends of the Earth Cymru Tidal fence - Pulse Tidal

14 Friends of the Earth Cymru Tidal fence scheme - Pulse Tidal

15 Middle Barrage - Tom Shaw - a Cardiff-Weston barrage + wall across Bridgewater Bay to Hinckley Point * would generate ~ 20 TWh/year * ‘ebb-only’ generation * Bridgewater Bay - birds ?

16 Offshore tidal lagoons - Tidal Electric Ltd

17 Friends of the Earth Cymru Offshore tidal lagoons TE Ltd developers say 50 sq miles would generate 17+ TWh/year (disputed) could generate anything from 1 - 20+ TWh/year depending on environmental acceptiblility - coastal effects long lasting - allows shipping - new habitat ? potentially lower cost / kWh

18 Geo-textile tubes - for lagoon walls

19 Geo-textile tubes - local silt / natural habitat

20 Filling geo-textile tubes

21 Friends of the Earth Cymru Offshore lagoons - coastal protection ? New techniques in protection & management July 2006 the £ 7.5 million DEFRA funded the Wallasea Wetland Creation Project in Essex 4 metre bunds ports near marine SACs considering using dredged material for inter-tidal recharge / salt marsh restoration ~ 4.5 million tonnes a year of maintenance dredged silt in Severn estuary - most disposed at sea but could fill geo-textile tubes…..

22 ‘Shoots’ scheme - barrage / reef / fence ? (1/7th of area of Cardiff-Weston barrage) English stones near SS crossing ~ 2 miles long and could carry the railway / flood protection barrage £ 1.5 billion 2.75 TWh/year high-level sluices - better for sediment, fish tidal reef at Shoots - similar cost /output ?

23 Tidal reef : Minehead - Aberthaw 14 miles

24 Tidal reef : Shoots alignment - 2 miles

25 Tidal reef : lock gates closed

26 Tidal reef - lock gates open

27 Friends of the Earth Cymru Combinations : lagoons, tidal reefs, fences the bigger barrages preclude some options lagoons could be built sequentially lagoons could be decommissioned any Shoots scheme could carry railway

28 Friends of the Earth Cymru Non-tidal generation - equivalent spend : (17 TWh/year of electricity for £ 15 - 23 billion) offshore windfarms 24 - 37 TWh/year CHP heat grids to 3 - 4.5 million homes - save 24 - 37 TWh/year in gas heating carbon capture and storage (CCS) of CO2 emissions ~ 3 pipelines to North Sea £1.5 billion - for 7 GW generating 50 TWh/year

29 10 MW aerogenerator - 1,000 for 33 TWh/year

30 Friends of the Earth Cymru Cardiff-Weston barrage - it would be difficult to claim on energy security grounds an ‘overriding public interest’ in risking significant damage to a major internationally important ecological site to derive around 1.4% of future UK energy demand

31 Friends of the Earth Cymru A Severn barrage or other major tidal energy schemes in or across the Severn Estuary would be monumental and iconic structures, a landmark in British history Friends of the Earth maintains its opposition to the Severn Barrage on ecological, economic, technical and navigational grounds A series of tidal lagoons and possibly a rail- bridging Shoots reef or barrage appear to be more environmentally friendly and cost-effective

32 Friends of the Earth Cymru Thank you for listening

33 Friends of the Earth Cymru Severn barrage as a flood defence ? IPCC 2007 estimate of 0.1 – 0.6 metres by 2100 - including recent analysis - possibly 1.0 - 1.2 metres by 2100 deglaciation of Greenland and West Antarctic Ice Sheet - rise up to about 4 or 5 m by 2500 If ice sheet collapses ~ 9 meters by 2500 the aim should be to reduce emissions as fast as possible


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