Severn Tidal EnergyThe Cardiff/Weston Barrage – Context and

Implications

Peter K Jones – Environmental Policy Officer

INTRODUCTION• Climate change: the policy context – global and UK

• Energy: the policy context – EU, UK and Wales• Renewable energy options: wind, solar, biomass, tidal• Severn estuary: habitats and wildlife• Severn estuary: tidal range• Severn estuary: energy project options – barrages,

lagoons, others• Cardiff/Weston barrage• SDC Report: ‘Turning the tide’• Frontier Economics Report: ‘Analysis of a Severn

barrage’• UK Government Feasibility Study• Conclusions

CLIMATE CHANGE• Consensual scientific conclusion (IPCC, 2007) that

volume of atmospheric Carbon Dioxide (CO2) should not exceed 400ppm if dangerous, possibly runaway global warming is to be avoided.

• CO2 level already at 386ppm and rising by more than 2ppm each year – likely to reach 400ppm by 2015.

• Average global temperature rise could be 3 or 4 C by mid-century, possibly triggering massive methane release from tundra and ocean floors.

• Government committed to 60% CO2 emission reduction by 2050 – likely soon to be increased to 80%.

ENERGY POLICY• European Union (EU) has set target of 20% of

energy from renewable sources by 2020.• Energy – electricity generation, heat and

transport, principally from burning fossil fuels – coal, gas and oil – which are the main source of carbon emissions.

• UK has 2020 target of 15% energy from renewables – 40% electricity generation from renewables.

• Welsh Assembly Government (WAG) aims to generate all Welsh electricity from renewable sources by 2025 – with or without a Severn barrage

RENEWABLE ENERGY• Unlike fossil fuels, which are finite and drive global

warming and climate change, renewable energy sources will always be available and, in operation, are almost entirely carbon-free.

• Principal renewables are: wind, both on- and off-shore; solar, both for heating and to generate electricity; biomass, both wood and crops; and tidal, both range and stream.

• Currently, c4.5% of UK electricity and 1.5% of energy are from renewable sources (cf 40% and 15% UK/EU targets) – tenfold increase required by 2020.

• UK tidal energy could contribute up to 10% of UK electricity.

• Severn Barrage could contribute 4.5% of electricity and 1% of energy.

Home to 68,000 waders and wildfowl: the Severn estuary has one global and two European conservation designations

SEVERN ENVIRONMENT

• The Severn has a mean tidal range of 8.2m (26 ft).

• Twice daily tidal movements• Produces 23,000ha of intertidal mudflats

and sandflats (including Bridgewater Bay) and extensive areas of saltmarsh.

• Five internationally important bird species: Bewick’s swan; mute swan; shelduck; pintail; dunlin.

• Special Protection Area; Special Areas of Conservation; Ramsar site; various SSSIs.

SEVERN ENERGY OPTIONS• Ten energy projects have been proposed:1. Five barrage lines, including Cardiff/Weston and the

Shoots, just south of the second road bridge.2. Two lagoon projects.3. Tidal fence.4. Tidal reef.5. Severn lake.

These are all tidal range options.Tidal stream technologies are not under consideration for

theSevern.

CARDIFF/WESTON BARRAGE• Would be constructed between Lavernock Point in

Penarth and Brean Down, near Weston-super-Mare.• Approximately 16 km (10 miles) in length.• Would generate 17 TWh of electricity pa (UK

current annual consumption of 380/400 TWh) – therefore around 4.5%.

• Load efficiency of 22/23%, cf offshore wind at 30/35%.

• Construction cost would be at least £15 billion and probably £20/25 billion.

• Cost comparable to constructing say 6 or 7 gas or nuclear stations, with total output of 40/45 TWh.

• Earliest availability – 2022.

SDC REPORT

• ‘’A tidal barrage would fundamentally change the nature of the Severn Estuary’’.

• Concluded that ‘’there is a strong case to be made for a sustainable barrage’’.

• No weakening of, or derogation from, the EU Birds and Habitats Directives.

• Barrage to be one part of much larger programme to cut UK carbon emissions by at least 60%.

• Publicly financed; public onwership.

FRONTIER ECONOMICS REPORT

• Looked at:The basis upon which the UK Government could justify supporting Severn tidal power, especially the proposed Cardiff/Weston barrage; and the costs and benefits of a barrage in the Severn.

• Concluded that it would be difficult to justify Government support specifically for a barrage; and that ‘’a large barrage on the Severn is expensive compared to alternative ways of generating renewable electricity’’.

Comparison of alternative generation costs (excluding solar and fuel cell technologies)

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Note: for details and full description, including limitations, see main report

Annual cost of generating output equivalent to a large barrage (2010£million)

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Note: for details and full description, including limitations, see main report

UK FEASIBILITY STUDY

• Aims to decide, after public consultation, whether or not a Severn tidal power scheme could be supported and on what terms.

• RSPB and other NGOs – WWF, FoE – involved.• Initial report promised for December 2008 – will

recommend whether to continue or whether ‘show-stoppers’ – environmental impact or cost.

• If continues, final report likely in Spring 2010.• If project proceeds: planning/public inquiry to

c2014.

CONCLUDING COMMENTS• Case against the Cardiff/Weston barrage:1. Would significantly reduce over-wintering designated

habitat for internationally and nationally important birds.

2. Would not be justified in cost terms in comparison with cheaper alternative renewable energy options, principally wind power.

• However, if Government rules that there are no alternatives: Imperative Reasons of Overriding Public Importance (IROPI: Habitats Regulations); would need to provide compensatory habitat for displaced birds – 14,500 inter-tidal ha likely to be lost – cost c£1 billion

• Will decision be evidence-based or political?

DISCUSSION/QUESTIONS

THANK YOU