The draft national policy statement for renewable energy infrastructure (EN-3), read together with the proposed revised overarching national policy statement (EN-1), also goes some way to address four of the main barriers to large-scale deployment of offshore capacity.
Ornithological “headroom”
Developers behind offshore wind projects are obliged to consider the potential impact of their projects on birds, including the potential for loss of habitat and collision with the rotating blades of the turbines.
Currently, cumulative impact assessments for ornithology are carried out in accordance with the ‘Rochdale Envelope’ approach – an approach involving the assessment of the effects of the wind farm within certain “worst case scenario” parameters, for example the lowest and highest potential tip heights of the blades. This approach offers a degree of flexibility in granting development consent when there is uncertainty over some of the detail of the project at the point of application. The detailed design of the wind farm is then approved after the developer has selected its wind farm components, such as the turbines.
As the government has acknowledged in the draft revised EN-3, however, this results in a disparity between the parameters set in the impact assessments and the final ‘as-built’ parameters that apply, with the latter typically being of smaller scale and impact. In theory, this creates “headroom” in the cumulative assessment of multiple wind farms in the same area of seabed, which could be made available for new projects. In other words, the effect of the ‘as-built’ projects are less than those assessed, meaning greater potential for additional projects.
It is envisaged that future development consent orders (DCOs) made under the Planning Act 2008 for offshore wind farms will need to include a provision that defines the final parameters of the ‘as-built’ project which cannot be exceeded so that other projects can make use of the resulting headroom for the purposes of their assessment. However, whether this is of practical assistance to future schemes will largely depend on the timing of when the final parameters are fixed as developers are unlikely to surrender headroom capacity at an early stage.
HRA
The draft revised policies recognise the thorny issue of Habitats Regulations Assessment (HRA) which entails consideration of the potential effects of offshore wind farm on protected habitats. HRA is currently a major constraint for offshore wind projects.
Measures to mitigate the impact of projects on protected habitats are set out in EN-1 and the government firmly encourages compliance with them. However, the government has made clear that potential adverse effects on protected habitats must be dealt with as early as possible in the consenting process and ideally pre-application. This is an approach that reflects the policy developed in the decision letters for Hornsea Three Offshore Wind Farm and the Norfolk Vanguard Offshore Wind Farms, though permission for the latter was later quashed by the High Court.
The government’s proposed new policy endorses the preparation of a “derogation case” – consideration of reasonable alternatives, IROPI (imperative reasons of overriding public interest) and compensatory measures – which can be submitted with the DCO application “without prejudice” to the applicant’s primary position that no adverse effects will occur.