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

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

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

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 selected projects taken forward for detailed studies Final decision by government

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

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)

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’ ?

Friends of the Earth Cymru

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

Friends of the Earth Cymru

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

Friends of the Earth Cymru Tidal stream - Seagen

Friends of the Earth Cymru Tidal fence - Pulse Tidal

Friends of the Earth Cymru Tidal fence scheme - Pulse Tidal

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 ?

Offshore tidal lagoons - Tidal Electric Ltd

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 TWh/year depending on environmental acceptiblility - coastal effects long lasting - allows shipping - new habitat ? potentially lower cost / kWh

Geo-textile tubes - for lagoon walls

Geo-textile tubes - local silt / natural habitat

Filling geo-textile tubes

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…..

‘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 ?

Tidal reef : Minehead - Aberthaw 14 miles

Tidal reef : Shoots alignment - 2 miles

Tidal reef : lock gates closed

Tidal reef - lock gates open

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

Friends of the Earth Cymru Non-tidal generation - equivalent spend : (17 TWh/year of electricity for £ billion) offshore windfarms TWh/year CHP heat grids to million homes - save 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

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

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

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

Friends of the Earth Cymru Thank you for listening

Friends of the Earth Cymru Severn barrage as a flood defence ? IPCC 2007 estimate of 0.1 – 0.6 metres by including recent analysis - possibly 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