Seascapes and offshore wind power

By Simon White

Simon White is Director at White Consultants.

Seascape sensitivity studies are playing an important role in guiding offshore wind energy at a strategic level, but they need to be applied effectively to help avoid delay to suitable developments which combat climate change and its related impacts.

Offshore wind energy production is a major contributor to mitigating climate change, so it deserves support from the profession. However, these developments are huge in terms of height of turbine and areas covered (illustration 2). They will be visible over very long distances, and some are likely to cause cumulative impacts with existing developments. In achieving energy production targets, can we (and should we) also protect the character and special qualities of our most valued seascapes? There is a strong case to do so, but to achieve this we need a more effective strategic planning approach.

The Crown Estate facilitates offshore wind development by periodically leasing defined areas of seabed. They have just completed Round 4 allocations, and are now considering deep waters in the Celtic Sea. In this instance, various consortia bid for the development rights within defined bidding and wind farm extension areas, and they then try to resolve seascape issues as part of the consenting process (using seascape and visual impact assessment (SVIA)). This can lead to conflict, especially where sites are allocated near nationally designated landscapes (illustration 1).

The recent LI publication responding to the climate crisis, Landscape for 2030, states that strategic landscape and seascape planning are an essential part of renewable energy placement and viability. So, how to achieve this?

Seascape sensitivity studies are playing an important role at both a national and a regional/local level. Current national policy statements drive decision-making and these lay emphasis on avoiding compromising the purposes of national landscape designations. Research for Natural Resources Wales (NRW) (1) analysed all available UK SVIAs to arrive at a consensus on the magnitude of visual effects for different sizes of wind turbine at different distances. This was used to define visual buffers to optimise the distance for different heights of turbine for different sensitivities of seascapes. This appears to have influenced the location of Round 4 projects in the Northern Wales and Irish Sea area, but should it not be used at an earlier stage in the Celtic Sea to avoid significant effects on the Pembrokeshire Coast? A UK Offshore Energy Strategic Environmental Assessment background paper (2) expanded on and refined the NRW research. It combined this with analysis of Met Office data over 10 years on the frequency of visibility distance out to sea and other information to recommend refined buffers for different sensitivities of seascape. Around the same time, an approach for assessing seascape sensitivity was developed for the Marine Management Organisation (3) . Both these documents inform both strategic and specific development assessments. The Marine Management Organisation (MMO) is the Government body (since 2009) responsible for “protecting and enhancing our marine environment, and support UK economic growth by enabling sustainable marine activities and development.” The MMO licenses and advises on development of offshore wind installations. (4) The MMO are creating marine plans for all English seas and coasts and these include seascape character assessments at a national level, as for Wales. These act as part of the baseline but sensitivity studies are needed to guide the location and scale of future marine development.

Worms Head, Gower – Atlantic Array windfarm was proposed offshore from this distinctive landform in the Gower AONB. This withdrawn windfarm would also have affected the Pembrokeshire Coast National Park and designations on the English coast – Exmoor National Park and North Devon Coast AONB.

© White Consultants Environment Ltd

Two potential areas for offshore wind development are to the east, off the Suffolk Coast and Heaths AONB, and to the south, off the South Downs National Park. In both locations, seascape sensitivity assessments 5 have now been completed, which apply the national studies. Seascape zones have been defined with different levels of sensitivity taking into account the recommended buffers and likely combined cumulative impact with existing developments.

The scale of offshore wind turbines – they are very large structures, rivalling the scale of nationally known and iconic tall structures such as the Shard at 305m and the London Eye at 135m. Current offshore windfarm applications include turbines up to 300m high, but some, in preapplication stages, are projected to use turbines 350m high and in the future ones that could reach up to 400m.

© White Consultants Environment Ltd

So overall, significant progress is being made to take a measured, strategic approach to the seascape effects of offshore windfarm development. However, more strategic sensitivity studies are needed, and it would be best if their findings are applied earlier in the planning process to guide wind farm location. This could avoid potential failure at a later stage in implementing an effective means of mitigating climate change.

References

1) Seascape and visual sensitivity to offshore wind farms in Wales: Strategic assessment and guidance. Stages 1-3. NRW Evidence Series. Report No: 315, NRW, Bangor, 2019.

2) Offshore Energy Strategic Environmental Assessment (OESEA): Review and update of Seascape and Visual Buffer study for Offshore Wind farms, BEIS/Hartley Anderson, 2020.

3) An approach to seascape sensitivity assessment, MMO, 2020.

4) Suffolk seascape sensitivity to offshore wind farms, White Consultants for Suffolk County Council and Suffolk Coast and Heaths AONB Partnership, 2020. South Downs National Park offshore wind farms buffer study, White Consultants for South Downs National Park Authority, 2021.