We were recently invited to share our thoughts with the Maritime and Coastguard Agency (MCA) UK Safety of Navigation (UKSoN) Committee on the navigation planning and risk assessment challenges posed by Floating Offshore Wind (FOW).
At the meeting, we presented the key findings of a study we undertook on behalf of The Offshore Renewable Energy (ORE) Catapult Floating Offshore Wind Centre of Excellence.
The purpose of the study was to establish how planning and risk assessment guidance and tools might be updated to meet the needs of FOW from a maritime and aviation perspective.
Through literature review, evaluating fictional realistic case studies and consultation with industry, we identified 19 areas where FOW differs from fixed foundations, three of which involve novel impacts where we concluded there is insufficient or no assessment guidance.
We consider these to be the three most significant challenges that developers and regulators will need to consider and manage from a safety of shipping and navigation perspective:
1. Management of wet storage sites
2. Safety and logistics in ports
3. Cumulative and in combination effects
1: Management of wet storage sites
Although floating offshore wind turbines are designed for use in deep water, during construction or maintenance phases, they may be temporarily moored in sheltered coastal waters or in port areas.
Challenge
Traditional assessments of offshore wind farms consist of three elements; array area, export cable route and, onshore.
The use of wet storage areas is a new element which imposes new impacts that have not previously been assessed. To date, all consent applications for FOWs have scoped out wet storage from their assessments.
Wet storage spatial area requirements can be significant and could pose similar or even greater impacts than array areas.
Being located nearer shore than the array area, there is greater potential to interact with nearshore vessel traffic and port approaches, such as inshore recreational, fishing or port vessel movements. The dynamic and temporary nature plus lack of space to avoid these constraints could pose significant impacts to these users.
2: Safety and logistics in ports
Ports are expected to play a key role in supporting the construction and maintenance of floating wind farms.
Potential capacity, infrastructure and safety impacts in nearshore waters, in and around ports will be more significant than for fixed wind farms.
Challenge
FOW increases the requirement for towage operations to move between ports, wet storage and array areas. There is therefore potential for frequent movement of floating offshore wind turbines within ports and harbour authority areas.
Construction/maintenance traffic could impede approaches and reduce access. Marshalling and towing requirements will place greater demand on port towage, pilotage and channel capacity.
Construction may be spread across multiple ports/harbours, increasing the complexity in assessment process. This may necessitate detailed logistics modelling to understand capacity and safety questions of interest to port authorities.
Often construction/O&M decisions are made post consent and thus not assessed during EIA. Such uncertainty limits specificity of assessment during EIA.
Additionally, ports themselves may require infrastructure development to be ready for FOW, such as new quaysides, reclamation areas or dredging. Furthermore, these facilities need to be designed with navigation safety in mind, ensuring they are balanced with the day-to-day operations of the port or include suitable risk controls such as Aids to Navigation.
3: Cumulative and in combination effects
Given the various development pipelines announced, it is likely that there will be multiple, concurrent floating projects in UK and Ireland waters.
Challenge
When projects are adjacent, impacts on shipping and navigation can increase exponentially such as spatial squeeze, cumulative deviation and corridor creation.
Ensuring that routes between offshore wind farms are safe, for the volume and types of traffic, and do not disrupt strategically important routes or lifeline ferry services will become an increasingly important issue for developers.
The concentration of construction and O&M activities in the relatively few suitable ports greatly increases the likelihood of such impacts.
One at a time, piecemeal assessments may no longer be fit for purpose and cumulative collaborative approaches between developers may be more suitable. For example, a cumulative regional NRA assessment was recently prepared for the Irish Sea Round 4 developments to address stakeholder concerns on the cumulative impacts.
Conclusion
Floating offshore wind developments bring different potential shipping, navigation and aviation risk and impacts when compared to fixed foundation projects.
To support the safe and sustainable growth of floating offshore wind, it is essential that industry guidance, tools and assessment practices are fit for purpose in identifying any potential impacts and ensuring appropriate mitigation measures are in place.
Whilst none of the navigation and safety challenges associated with floating offshore wind are insurmountable, it is crucial to get ahead of these impacts before the first commercial project.
Here at NASH Maritime our experienced risk specialists are familiar with these three challenges and know how they can be assessed and managed. Get in touch to discuss how we can help you realise your project ambitions.
Further reading
A summary report of the work we undertook on behalf of The Offshore Renewable Energy (ORE) Catapult Floating Offshore Wind Centre of Excellence for has now been published.
