Turning the tide The Sustainable Development Commission is the Government’s independent watchdog on sustainable in the UK Tidal Power development, reporting to the Prime Minister, the First Ministers of Scotland and Wales and the First Minister and Deputy First Minister of Northern Ireland. Through advocacy, advice and appraisal, we help put sustainable development at the heart of Government policy. www.sd-commission.org.uk England (Main office) 55 Whitehall London SW1A 2HH 020 7270 8498 [email protected] Scotland 3rd Floor, Osborne House 1-5 Osborne Terrace, Haymarket, Edinburgh EH12 5HG 0131 625 1880 [email protected] www.sd-commission.org.uk/scotland Wales c/o Welsh Assembly Government, Cathays Park, Cardiff CF10 3NQ Turning 029 2082 6382 Commission Development Sustainable [email protected] www.sd-commission.org.uk/wales Northern Ireland Room E5 11, OFMDFM the Tide Castle Buildings, Stormont Estate, Belfast BT4 3SR 028 9052 0196 Tidal Power in the UK [email protected] www.sd-commission.org.uk/northern_ireland Turning the Tide Tidal Power in the UK Contents Executive Summary 5 1 Introduction 15 1.1 Background to this project 16 1.2 Our approach 17 1.3 UK tidal resource 19 1.3.1 Two types of tidal resource 19 1.3.2 Electricity generating potential 22 1.3.3 Resource uncertainties 22 1.3.4 Timing of output from tidal sites 23 1.3.5 Transmission system constraints 25 1.4 Energy policy context 28 1.4.1 Current Government policy 28 1.4.2 The SDC’s advice 28 1.5 Public and stakeholder engagement 29 1.5.1 Tidal power and sustainable energy 29 1.5.2 Tidal power technologies 30 1.5.3 Conditions for acceptability 31 1.6 Report Structure 32 2 Tidal Stream 35 2.1 Technology overview 36 2.1.1 Tidal stream devices 36 2.1.2 Current level of development 37 2.1.3 Future prospects 37 2.2 Current Government policy 38 2.2.1 Tidal stream funding 38 2.2.2 Regulatory and planning framework 40 2.2.3 European environmental legislation 40 2.2.4 Seabed licences/leases 40 2.2.5 Role of nature conservation agencies 41 2.3 Environmental, social and economic impacts 41 2.3.1 Physical configuration of devices 41 2.3.2 Environmental considerations 42 2.3.3 Summary of environmental impacts 45 2.3.4 Social and economic impacts 46 2.4 Opportunities and barriers 48 2.4.1 Funding regime 48 2.4.2 Grid constraints 50 2.4.3 Getting the regulatory framework right 52 2.4.4 Dealing with information gaps 53 2.4.5 Utilising the EMEC resource 54 2.4.6 Creating a development path 55 3 Tidal Range 57 3.1 Tidal range technologies 58 3.1.1 Tidal barrages 58 3.1.2 Tidal lagoons 59 3.2 Funding regime 62 3.3 Exploring the policy options 62 3.4 Tidal range case studies 63 Mersey Estuary 63 Loughor Estuary 65 Duddon Estuary 65 Wyre Estuary 66 Thames Estuary 66 4 A Severn Barrage 69 4.1 Background 70 4.1.1 Chapter outline 70 4.2 Strategic overview of the Severn Estuary resource 70 4.2.1 The Severn Estuary 71 4.2.2 Severn barrage options 72 4.2.3 Alternatives to a barrage 74 4.2.4 Compatibility of options 74 4.2.5 Dealing with data constraints 75 4.3 Electricity output and characteristics 75 4.3.1 Contribution to electricity supply 76 4.3.2 Method of operation 76 4.3.3 Load factor 76 4.3.4 Output profile 77 4.3.5 Implications for grid management 79 4.3.6 Implication for the transmission system 81 4.4 Carbon emissions 83 4.4.1 Carbon payback 83 4.4.2 Carbon reduction potential 83 4.5 Physical implications of a barrage 84 4.5.1 Sound science and uncertainty 85 4.5.2 Water levels and currents 85 4.5.3 Morphology 87 4.5.4 Sedimentary processes 87 4.5.5 Decommissioning 88 4.6 Environmental impacts 89 4.6.1 Scope of environmental review 89 4.6.2 Protected status of the Severn Estuary 89 4.6.3 Habitats and ecology 93 4.6.4 Water quality 97 4.6.5 Birds 98 4.6.6 Fish 100 4.6.7 Landscape and visual 101 4.6.8 Climate change and the Severn 102 4.6.9 Impact of a barrage on protected features 103 4.6.10 Biodiversity impact of a Severn barrage 105 4.7 Economy and society at a regional level 105 4.7.1 Ports and navigation 105 4.7.2 Transport links 107 4.7.3 Coastal defence and flood protection 109 4.7.4 Employment 113 4.7.5 Development and housing 113 4.7.6 Leisure and tourism 115 4.7.7 Fishing activities 116 4.7.8 Aggregates industry 116 4.8 Cost and financing 117 4.8.1 Cost of construction 117 4.8.2 Unit cost of output 117 4.8.3 Level of Government involvement 120 4.8.4 Financing options 122 4.8.5 Consideration of ancillary benefits 125 4.9 Public and stakeholder opinion 125 4.9.1 Public attitudes and opinions 125 4.9.2 Stakeholder attitudes and opinions 127 4.10 Policy process and good governance 127 4.10.1 Research and assessment stages 128 4.10.2 The importance of engagement 128 4.10.3 Relevance of the Directives 129 4.10.4 Complying with the environmental legislation 131 5 Conclusions and Recommendations 135 5.1 A consensus view 136 5.2 Tidal power in the UK 136 5.2.1 Tidal stream 136 5.2.2 Tidal lagoons 138 5.2.3 Tidal barrages 139 5.3 Conditions for a sustainable Severn barrage 139 5.3.1 Energy policy context 140 5.3.2 Ensuring the public interest 140 5.3.3 Complying with the environmental legislation 142 5.3.4 Our advice to Government 144 5.3.5 Moving forward 146 6 References 149 Executive Summary The UK has the potential to generate large amounts Exploiting our tidal energy resources will require of clean and secure electricity from the tides. Using concerted action on a number of fronts. The tidal both types of tidal resource – tidal stream and tidal power technologies that could be deployed are very range – we could supply at least 10% of the UK’s different in both design and level of development. electricity if fully exploited, around 5% from each Tidal stream devices are currently at the resource. Such a substantial prize deserves very demonstration stage, and will require many years close attention as part of much wider action aimed of targeted support to reach commercial maturity. at tackling the twin challenges of climate change Tidal barrages, on the other hand, are a proven, but and energy security. highly capital-intensive option that would require a This report discusses both tidal stream and tidal strong lead by Government to be built. With tidal range technologies, and considers a wide range lagoons, a lack of evidence means that the priority of research, including the results of a public and should be filling information gaps through practical, stakeholder engagement programme. It presents on-the-ground experience so that long-term viability the Sustainable Development Commission’s can be better assessed. position and recommendations on proposals for a However, all tidal technologies have a number Severn barrage which, if built, would utilise a very of environmental, social and economic impacts that large proportion of the UK’s tidal range resource, need to be considered. In particular, the impact of a and could generate large quantities of low carbon Severn barrage on internationally protected habitats electricity for over 120 years. and species, is of great concern. There is minimal conflict between the exploitation In this report, the Sustainable Development of tidal stream and tidal range resources, or between Commission (SDC) lays out a series of the technologies that might be deployed. The best recommendations for Government on how to tidal stream sites are in the north of Scotland, develop the UK’s tidal power resources. On the issue with significant potential also around north Wales, of a Severn barrage, we consider the conditions Northern Ireland, and the Channel Islands. The tidal under which such a scheme would be consistent range resource is concentrated in the estuaries off with the principles of sustainable development, the west coast of Britain, including the Severn, the and issue clear advice to Government on how this Mersey and the Humber. should be taken forward. Tidal stream technologies In addition to having an excellent tidal stream and practical. Innovation, and the development of resource – one of the best in Europe – the UK is new low carbon technologies such as tidal stream currently leading the world in the development of generators, needs to be a fundamental part of the a wide range of tidal stream devices. The long-term UK’s response to the challenge of climate change. potential for this new industry – both in terms of its The Government must increase R&D expenditure and contribution to UK electricity supply, and its export become less risk-averse in supporting innovation. potential – is considerable. The UK’s success so far As a result of the Government’s plan to introduce can be attributed to the ingenuity and perseverance technology banding to the Renewables Obligation, of the device developers combined with the there is now an opportunity to build on the success commitment shown to date by the UK and Scottish of the Scottish Government’s marine energy Governments.