Select Committee on European Union Written Evidence

Memorandum by PB Power

PRESENTATION MADE TO THE COMMITTEE ON 23 JUNE 2008 SUMMARY OF MAIN TIDAL RANGE PROPOSALS REVIEWED BY THE SUSTAINABLE DEVELOPMENT COMMISSION IN 2007

Sustainable Development Commission

Brief

—  To review tidal power in the UK

Process

—  Evidence Based

—  Informed by Research

—  Focus on Tidal Range (Barrages / Lagoons) and Tidal Stream Technologies

—  Stakeholder Engagement

—  Published Reports and Recommendations

Output

—  "Turning The Tide"-main report

—  5 Supporting Research Reports

For the Severn Estuary|.

SDC Findings

  1.  There is no conflict between Tidal Stream and Tidal Range Technologies

  2.  Strong Case for Tidal Lagoon Demonstration Project

  3.  Strong Case for a sustainable Severn Barrage

  4.  Climate change adaptation may present an "environmental opportunity" when considering compensatory habitats

  5.  Should be publicly led with innovative financing to allow public risk / reward to be in balance

MAIN OPTIONS

Cardiff Weston Barrage

—  17TWh per year electricity generation costing £15 billion

Shoots Barrage

—  2.75TWh per year electricity generation costing £1.5 billion

Tidal Lagoons

—  Swansea Bay Lagoon generates up to 187 GWhper year at a cost of £250 million

ISSUES

Environment

—  Habitats Directive

—  Wild Birds Directive

—  Water Framework Directive

—  Appropriate Compensation

Commercial

—  Navigation Impacts

—  Energy Pricing

—  Construction Costs

—  Private / Public Split

Cardiff Weston Tidal Barrage

—  8640 megawatts installed capacity

—  17,000 million kilowatt hours annual output, equal to 4.4% current UK electricity demand 216 turbine generators, 9 metres diameter, rated at 40 megawatts each

—   166 sluices, total area 35,000m2

—  16 km length

—  2 locks for ships

—  2 locks for pleasure craft

—  480m2 enclosed area of basin

LOCATION

—  Between Brean Down and Lavernock Point

COST

—  £15 billion

NON ENERGY BENEFITS

—  Flood Defence

—  Potential for new Road and Rail Crossings

OPERATION

—  Generates on the Ebb Tide

—  Predictable but intermittent energy

—  Requires additional national grid infrastructure

Shoots Tidal Barrage

—  1050 megawatts installed capacity

—  2,750 million kilowatt hours annual output, equal to 0.8% current UK electricity demand

—  30 turbine generators,7.5 metres diameter, 35 MW

—  42 sluices, total length 1.26km

—  6km barrage length

—  1 lock for ships and pleasure craft

—  93 sq km enclosed area of basin

OPERATION

—  Generates on the ebb tide

—  Refills on the flood tide

—  Downstream: Tidal levels similar to today's

—  Upstream: Upper tidal levels marginally reduced and tidal range approximately halved

—  Large number of sluice gates to allow tidal basin to be recharged using only the upper water levels where silt load is lowest

—  Navigation upstream of barrage through ship lock requirements determined by Gloucester Harbour Trustees

COST

—  £1.5 billion

NON ENERGY BENEFITS

—  Flood Defence -Gloucestershire

—  Rail Link adjacent to existing Severn Tunnel

CONSTRUCTION PROGRAMME

—  4 to 5 Years

Tidal Lagoons

MANY DIFFERENT PROPOSALS

—  Russell Lagoons

—  Swansea Bay

—  Other shallow locations within the Estuary—eg Bridgewater Bay

—  4500MW potential capacity identified in the Severn

SWANSEA BAY LAGOON

—  Promoted by Tidal Electric Limited

—  Estimated Capital Cost:£81.5 million

—  Annual Output:187GWh

(Tidal Electric Limited Figures)

  NB: A separate DTI Review however challenged these figures, giving a total cost estimate of £255 million and energy yield of 124GWh per year.

  A more recent npower study in Liverpool Bay for a similar sized scheme estimated constructions costs of £108-£135 million

COST BENEFIT

Option	Capital Cost (£m)	Annual Output (GWh)	Cost per kWh at 8% (p/kWh)
Cardiff Weston Barrage	15,000	17,000	8.54
Shoots Barrage	1,500	2,750	6.80
Swansea Bay Lagoon (TEL)	81.5	187	4.15
Swansea Bay Lagoon (DTI)	255	124	18.39

23 June 2008

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