5.4. Offshore Air Quality

5.4.1. Introduction

  1. This section of this Scoping Report presents the relevant offshore air quality aspects to the Array and considers the scope of assessment on offshore air quality from the construction, operation and maintenance, and decommissioning of the Array.

5.4.2. Study Area

  1. As the focus of this Scoping Report only lies on the offshore components (i.e. the Array), ecological and human receptors (e.g. residential areas and public spaces) within the nearshore vicinity are not relevant due to their distance from the Array (at least 80 km). Therefore, the study area for offshore air quality will be the site boundary.

5.4.3. Baseline Environment

  1. The literature used to support this Scoping Report is comprised of the desktop reports, summarised in Table 5.9   Open ▸ .


Table 5.9:
Summary of Key Desktop Reports Used to Inform the Offshore Air Quality Scoping Assessment

Table 5.9: Summary of Key Desktop Reports Used to Inform the Offshore Air Quality Scoping Assessment


  1. Poor air quality may have impacts on human health, infrastructure, and the environment. Atmospheric pollutants that can be emitted into the environment include sulphur dioxide (SO2), carbon dioxide (CO2), NOX which is comprised of NO2 and nitrogen oxide (NO), PM10, and PM2.5. Oil and gas platforms pose the highest risk of air pollution in the offshore energy sector, however offshore wind farms may be responsible for some atmospheric pollutant emissions due to vessel and equipment usage. However, atmospheric pollutant emissions from vessel and equipment usage as a result of the Array will likely be similar to those associated with typical shipping activity, and the increase in vessel usage will be low in comparison to baseline levels. There are limited resources available on air quality at offshore wind farms and air pollution levels in the offshore environment, particularly at such distances from the coast (approximately 80 km).
  2. The National Emission Ceilings Directive (NECD) was revised in 2016 (NECD 2016/2284/EU) to delegate emission reduction commitments for NOx, SO2, non-methane volatile organic compounds (NMVOC), ammonia (NH3), PM10, and PM2.5 for 2020 and 2030 (Official Journal of the European Union, 2016). The UK committed to set emission ceilings through the NECD and has met the reduction targets for all the mentioned pollutants each year since 2010, with the exception of NOX in 2010 (NECD, 2020).
  3. In Scotland, various strategies and legislation have been implemented with the aim to reduce emissions, such as Cleaner Air for Scotland (Scottish Government, 2022a), which sets out how the Scottish Government proposes to reduce air pollution to protect human health between 2021 to 2026. Similarly, the Climate Change (Emissions Reductions Targets) (Scotland) Act 2019, sets a target for net zero emissions by 2045 and plans for the establishment of low emission zones in Scotland’s four largest cities in the Transport (Scotland) Act, 2019.
  4. In 2021, NAEI undertook a review of the emissions of eight priority air pollutants in Scotland: carbon monoxide (CO), lead, NH3, NMVOCs, NOx, PM10, PM2.5, and SO2. Between 2005 and 2019, the following decreases in pollutant emissions were reported:
  • 85% for SO2;
  • 53% for NOx;
  • 51% for CO;
  • 37% for lead
  • 33% for PM2.5;
  • 30% for PM10;
  • 15% for NMVOCs; and
  • 9% for NH3 (NAEI, 2021).

                        Site-specific survey data

  1. There were no site-specific surveys undertaken to inform this Scoping Report for offshore air quality. This is due to the availability of sufficient existing information to describe the baseline environment.

5.4.4. Potential Array Impacts

  1. A list of all potential impacts on offshore air quality which may occur during the construction, operation and maintenance, and decommissioning phases of the Array in the absence of designed in measures is included in Table 5.10   Open ▸ .


Table 5.10:
Potential Impacts Identified for Offshore Air Quality in the Absence of Designed In Mitigation Measures

Table 5.10: Potential Impacts Identified for Offshore Air Quality in the Absence of Designed In Mitigation Measures


5.4.5. Designed In Measures

  1. There are no designed in measures specific to offshore air quality, however activities during all stages of the Array will adhere to good industry practice and relevant guidance (e.g. IAQM, 2018).

5.4.6. Potential Impacts After the Implementation of Designed In Measures

  1. Table 5.11   Open ▸ describes the potential impacts to offshore air quality that have been scoped out of the assessment presently.

5.4.7. Proposed Approach to the Environmental Impact Assessment

  1. There is no proposed approach to the Array EIA applicable to offshore air quality as it is proposed to be scoped out of further assessment.

5.4.8. Potential Cumulative Effects

  1. The nearest offshore wind farm projects are Seagreen 1 (formerly known as Seagreen Alpha and Bravo), Seagreen 1A, and Berwick Bank Offshore Wind Farm, located 57 km, 66.4 km, and 56.77 km respectively, away from the site boundary. There are also other offshore wind farm projects in the Firth of Forth region, such as Inch Cape and Neart na Gaoithe, however these are located further inshore (86.90 km, and 105 km, respectively) ( Figure 5.2   Open ▸ ). There are also a number of ScotWind Awarded Sites in the vicinity of the Array, such as Morven (5.5 km), Bellrock (8.67 km), Cluaran Deas Ear (25.36 km), CampionWind (44.15 km), and Muir Mhòr (51.38 km) ( Figure 5.2   Open ▸ ). Due to the lack of a receptor-impact-pathway between the Array and the other aforementioned offshore wind farm projects, it is anticipated that there will be no cumulative effects regarding offshore air quality for the Array and these projects. In addition, these projects are all at different stages of development, further reducing the potential for cumulative effects. Similarly, there are also leasing and oil and gas activities within the North Sea, however these activities are also not expected to result in cumulative effects due to distance and the lack of receptor impact pathways for offshore air quality.
  2. Due to the low likelihood of impacts to offshore air quality arising from the Array, cumulative effects due to potential overlaps in construction with other offshore wind projects are also unlikely. There may be potential cumulative effects for the Ossian project as a whole (i.e. construction of the onshore and intertidal applications), however, these will not affect offshore air quality, and are thus, not considered within this Scoping Report.

5.4.9. Potential Transboundary Impacts

  1. Appendix 3 presents the transboundary impacts screening which has been carried out for the Array. This screening exercise identified that there is no potential for transboundary impacts upon offshore air quality due to construction, operational and maintenance, and decommissioning impacts of the Array. This is due to potential impacts associated with the Array activities on offshore air quality expected to be minimal, non-significant and highly localised.

5.4.10. Scoping Questions to Consultees

  • Do you agree that the existing data available to describe the offshore air quality baseline remains sufficient in relation to the Array?
  • Do you agree that the assessment of offshore air quality receptors should be scoped out of the Array EIA including cumulative and transboundary effects ( Table 5.11   Open ▸ )?

5.4.11. Next Steps

  1. The next step is to seek agreement on the proposal to scope offshore air quality out of further assessment within the Array EIA Report. Additionally, the Climatic Effects Assessment is included in section 5.5.


Table 5.11:
Impacts Proposed to be Scoped Out of the Array Assessment for Offshore Air Quality

Table 5.11: Impacts Proposed to be Scoped Out of the Array Assessment for Offshore Air Quality