Out-Law / Your Daily Need-To-Know

Out-Law Analysis 4 min. read

National planning policy revisions support UK offshore wind growth

Offshore wind large waves challenges

Planned revisions to UK planning policy for major energy infrastructure reinforces support for the growth in offshore wind generation and aligns with the UK government’s target of achieving 40GW of capacity from the sector by 2030.

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.


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. 

Phillips Gareth_May 2020

Gareth Phillips


BEIS guidance on alternatives is sensible and if properly applied should help to unlock UK offshore wind capacity

BEIS gives helpful guidance on the consideration of alternatives, which is framed to reflect the level and urgency of need for new energy infrastructure. An examination of alternatives must consider whether there is a “realistic prospect of the alternative delivering the same infrastructure capacity… in the same timeframe” and recognise the need for commercial viability of the project. Draft EN-1 is clear that development at one site should not be refused simply because fewer adverse impacts would result at another site, recognising that all suitable sites may be needed. 

Draft EN-3 now also gives guidance in relation to offshore wind farm developers working collaboratively on shared mitigation, compensation and monitoring where appropriate, so-called industry or strategic-level solutions.

Hornsea Three was granted a DCO on 31 December 2020 and is the first offshore wind farm to be consented despite predicted adverse effects on European sites. It is widely regarded as a turning point in offshore wind consenting. Developers must now prepare to deal with HRA issues proactively in their application and provide BEIS with a pathway to grant consent via derogation if necessary.

BEIS guidance on alternatives is sensible and if properly applied should help to unlock UK offshore wind capacity. The issue of compensatory measures remains key however and whilst the policies encourage developers to work together, the revised national policy statement does not deal with the urgent need for a strategic solution. BEIS, Defra and statutory nature conservatory bodies need to work with developers for the target of 40GW by 2030 to be achievable.   

Offshore transmission network

The revised EN-1 and EN-3 also support a move away from individual end-to-end radial grid connections for offshore wind, in favour of a coordinated approach. This reflects the ongoing offshore transmission network review being conducted by Ofgem. Options for developers highlighted include an offshore grid connection point, or connection via a multi-purpose interconnector. Going forward it is anticipated that the grid connection will be consented separately from the offshore wind farm application, or the DCO application for the offshore wind farm would include transmission assets required to connect to an offshore transmission network connection point.

Though the offshore wind industry is preparing itself for a move to coordinated transmission,  more than just planning policy is required to facilitate this as there are significant regulatory hurdles to overcome for meaningful coordination to become a reality. Until such a time as the appropriate regulatory frameworks are in place, it is helpful that BEIS acknowledges that the importance of accelerating coordinated projects does not mitigate against the need for standalone network projects. This should include traditional point to point connections for offshore wind projects.

Competing seabed usage

The development of the seabed for offshore wind and the potential for conflict with other technologies required for the delivery of the UK’s ‘net zero’ emissions target by 2050, such as the storage of carbon within the UK continental shelf (UKCS), is recognised in the updated draft of EN-3. The policy recommends engagement between developers and the Crown Estate, including the use of Statements of Common Ground and agreed mitigation measures but unfortunately does not provide any further detail or guidance on how “a solution can be found that optimises the capacity of the UKCS to enable net zero”.  Therefore, the extent coexistence can be achieved will continue to turn on how flexible developers can be in accommodating each other’s projects.

Co-written by Amy Stirling and Claire Brodrick of Pinsent Masons.

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