The expansion of offshore wind farms is accelerating, driven by Europe’s ambitions to achieve climate neutrality while strengthening energy security and reducing dependence on fossil fuels. However, as deployment increases, ensuring that this growth remains sustainable requires addressing a growing range of environmental, social, and technical challenges. A new report maps out the multiple and sometimes competing factors and assessment tools capable of effectively informing decision-makers.
What sort of tools currently exist to help and inform decision makers?
Two key instruments currently form the backbone of environmental assessment practices: Strategic Environmental Assessment (SEA) and Environmental Impact Assessment (EIA). SEA applies to plans and programmes, such as marine spatial plans or national energy strategies, and helps evaluate their potential environmental consequences before decisions are made. EIA focuses on specific projects and assesses their potential environmental impacts before development approval is granted.
Alongside these core instruments, other approaches contribute to sustainability assessment:
- Life Cycle Assessment (LCA) evaluates environmental impacts throughout the entire life cycle of a project, from materials and construction to operation and end-of-life.
- Cumulative Impact Assessment (CIA) examines the combined effects of multiple activities over time and space, which is particularly important in increasingly used marine areas.
- Social Impact Assessment (SIA) considers impacts on communities and socio-economic activities.
- Other regulatory frameworks, such as Appropriate Assessment under the Habitats Directive, the Water Framework Directive (WFD), and the Marine Strategy Framework Directive (MSFD), provide additional safeguards for biodiversity and marine ecosystems.
What are some of the limitations of existing environmental assessment tools?
Together, these tools provide an essential foundation for sustainable offshore wind development. But despite the many existing options, current assessment practices can fall short. One of the main challenges is the fragmentation of the tools. Indeed, the tools are substantially different in terms of:
- scope
- level of integration
- data requirements
- timing and influence within decision-making processes
Moreover, some are mandatory regulatory procedures, while others are analytical approaches used as needed.
As a result, sustainability considerations are not always addressed consistently across all stages of an offshore wind farm’s life cycle.
There is also huge variability in the implementation of environmental assessment requirements because of differences between jurisdictions. Observations from Estonia, Portugal, Spain, and Denmark show a consistent pattern: SEA plays a central role in early planning and siting phases, while EIA is applied consistently through project design, construction, and operation, but its presence weakens considerably in the later lifecycle phases.
Other assessment tools are often integrated within these two broader frameworks rather than conducted as stand-alone exercises, which makes their actual influence harder to assess. In practice, LCA and SIA remain underused across all four countries. Repowering and decommissioning are largely missing from current assessment practices, even though these phases are of primary importance for circularity, long-term environmental impacts, and future sea use. This has direct consequences for the predictability of planning processes going forward.
Why does SUSTAINOW’s work matter in this context?
Current assessment tools are well-designed to identify and reduce negative impacts, but they are not built to actively pursue positive ones. Based on this, several key areas to explore have emerged: the need to identify priority areas for improving decision support, to develop an enhancement approach alongside mitigation, to strengthen lifecycle and system-oriented assessment, and to improve the integration of tools across life-cycle phases and decision levels.
It is in this context that SUSTAINOW brings European experts together to address these issues. The project is developing a set of open-access tools that improve how marine data is shared between stakeholders, and that integrate environmental, social, and economic assessments:
- The cross-border marine data platform addresses the fragmentation between jurisdictions, improving access and interoperability between countries.
- The evidence-based siting tool supports planners in identifying the best locations in terms of feasibility and environmental impact, bringing decision support to the earliest, highest-leverage phase of the lifecycle.
- The project design tool brings the remaining two needs together: it strengthens lifecycle and system-oriented assessment by evaluating impacts from early design through to decommissioning, and it supports a genuine enhancement approach by considering these impacts holistically rather than in isolation.
Explore the report here.
