Scottish Marine and Freshwater Science Volume 3 Number 2: Scoping Study For Offshore Wave Energy Development In Scottish Waters

1 Background

The Scottish Government has set a range of challenging targets for energy and climate change. These recognise the potential to take advantage of the extensive marine energy resources (wind, wave and tidal power) available in Scottish waters and include meeting at least 30% of total energy demand from renewable sources by 2020, incorporating:

• 100% of electricity demand from renewables (31% by 2011)
• 11% of heat demand from renewables
• 10% of transport fuel from renewables

In addition, the Climate Change (Scotland) Act 2009 sets statutory targets of at least 42% emissions cuts by 2020, and at least 80% by 2050.

It was recognised several years ago that Scotland was potentially uniquely placed in relation to the potential for wave energy development, with a long coastal margin (including offshore islands) exposed to the open waters of the North Atlantic. A Strategic Environmental Assessment of the potential for wave and tidal power developments in Scottish Territorial Waters to the north and west of Scotland (Scottish Government, 2007) confirmed this potential, and identified the need to ensure that environmental interactions, and interactions with other users of the sea were taken into account when creating development plans and considering individual projects in the licensing process.

Subsequently, renewable energy, including marine renewables, has become a key aspect of the Scottish Government's economic strategy. The need to encourage technological development and install early projects in the sea led to the creation of the Saltire Prize ( http://www.sdi.co.uk/sectors/saltire-prize.aspx). Smooth development of potential Saltire Prize projects was assisted by the adoption of a marine planning approach to the identification of areas with the necessary wave or tidal stream resource, and in which interactions with other uses, and sensitivities, of the sea were minimised. This was achieved through a Scoping Study for wave and tidal power (Harrald and Davies, 2010), and supporting Regional Locational Guidance ( RLG, Harrald et al., 2010). The result is that there are now more than projects with exclusivity agreements for lease for wave and tidal power in Scottish waters, together with a further 11 commercial scale projects (a total of 1.6 GW) in the Pentland Firth and Orkney Waters Strategic Area.

The Saltire Prize Scoping Study was developed from a brief that emphasised the need to avoid sensitive areas. The report (Harrald and Davies, 2010) noted that these conditions were more restrictive than might be applied in wider development contexts. Since the Saltire Prize Scoping Study was completed, new information on interactions with the environment and other users has become available, together with new ways to handle the underlying data. Furthermore, the Scottish Government is now responsible for marine planning out to the 200 mile limit. These, and other factors, have come together to indicate a need to undertake a new Scoping Study for wave power, covering all Scottish waters, together with new Regional Locational Guidance, to form the basis for a development plan and supporting Sustainability Appraisal.

The new Scoping Study described in this report is one of a series covering offshore wind, wave and tidal stream energy. They form part of a process of regular revisions and updates of sectoral plans for offshore energy, including energy from wave power. The process to develop the Plan is being supported by using The Crown Estate's Marine Resource System ( MaRS) to map zones of broad environmental sensitivity and technical opportunities and constraints.

The MaRS system is a powerful tool for the handling and integration of a wide range of spatial data referring to environmental and technical factors that can influence the development of offshore wave energy (and other activities). The integrated data are presented as spatial models which map the constraints applying in potential development areas. In order to apply the MaRS tool, it is necessary for the user to make a number of decisions regarding the data to be included in the models and the way in which the data are to be handled. A system of scoring and weighting of information held in MaRS is used to produce graduated maps of the least to greatest technical, and subsequently environmental, and socio-cultural sensitivity. From these outputs, broad areas of technical opportunity and relatively low constraint on development can be identified and explored in more detail through Regional Locational Guidance.

The first Scoping Study for offshore wave energy in Scottish waters was undertaken in 2010. Experience of both that exercise and subsequent exercises ( e.g. Davies and Watret, 2011) has shown that the conclusions are sensitive to technical factors, such as the categorisation of data layers as representing complete (exclusion models) or partial (constraint models) constraints on development, the weighting applied to the layers, and the classification system used to create the scores. However, the degree of sensitivity differs between sea areas.

Furthermore, a sensitivity analysis of the outputs from the Draft Plan for offshore wind (Davies and Aires, 2011) noted that improvements in the available data had occurred since the Draft Plan had been prepared. For example, European Seabird at Sea ( ESAS) data were now available in a compiled form suitable for inclusion in spatial modelling. Other data layers are progressively being updated and improved, demonstrating the need to keep sectoral plans under cyclical review to ensure that the outputs are as robust as possible. taking account of the best current information and data handling methods. The sensitivity analysis concluded that, as additional data and monitoring information, and improved data handling procedures, become available, these should be incorporated into the emerging iterative marine planning process, as applied to opportunities for development in STW, and to opportunities further offshore.

A process was therefore put in place by Marine Scotland to develop a Scoping Report for the potential for wave energy development in Scottish waters out to 200 nautical miles. It is intended that that this will inform the marine planning process by leading to the development of Regional Locational Guidance for wave energy development, which in turn will be the basis for a Sectoral Marine Plan and Sustainability Appraisal to cover wave energy development in Scottish waters.