4. Assessment of Impacts on Other Marine Users and Interests
This section builds on the Baseline provided in Chapter 3, and assesses the potential national and regional interactions between short term options in the Draft Plan and other marine activities. The impacts associated with these interactions are also quantified where possible.
4.2 Commercial Fisheries
This analysis assumes that all of the short term options have the potential to affect commercial fisheries, since fishing activity currently takes place, to a greater or lesser extent, within all the regions affected by the short term options. Also, all sites lie completely or partially within spawning or nursery grounds for one or more of the commercial species impacts to which could affect future fish stocks.
Based on consultation and previous studies of offshore wind farm impacts, the construction and operation of offshore wind farms has the potential to impact on commercial fishing through:
- Disturbance of mobile species and disruption or damage to habitats, nursery and spawning grounds, direct damage to sessile species, leading to displacement of or reduction in fish and shellfish resources;
- Reduction in or loss of access to traditional fishing grounds;
- Displacement of activity to existing (less profitable) fishing grounds;
- Consequent increase in fishing pressure and competition on alternative available grounds;
- Obstruction of navigation routes to and from fishing grounds leading to increased steaming times;
- Fouling of fishing gear on cables and seabed infrastructure;
- Safety issues for fishing vessels in transiting wind farm arrays or in diverting around them; and
- Potential reduced Catch Per Unit Effort (which is exacerbated by cumulative effects of other pressures on fishing areas, including other offshore wind farm, Marine Protected Areas, oil and gas, aggregate extraction, dredging and port developments) and consequential loss of profit.
It is important to consider the nature and the period of the impacts. Some will be permanent, for example, loss of seabed habitat and associated ecological assemblages in the footprint of turbine structures. Other effects may be temporary, for example, disturbance due to seabed preparation or piling. The duration and timing of temporary effects is relevant along with the potential for interactions with other sites and or activities which may have cumulative in-combination effects. (Marine Scotland, 2010a)
Some of the impact risks can be mitigated by developers through the careful siting of offshore wind farm, careful timing of construction work, configuration of turbines to allow navigation and fishing in between, adequate cable burial, appropriate marking and lighting of developments, and adequate early consultation with the fishing industry.
Offshore wind farms also have the potential to have positive impacts on commercial fishing, for example opportunities for certain gear types (e.g. static gear) within the offshore wind farm if mobile gears are displaced.
Some benefits for enhancing biodiversity may arise from the removal of trawling activity and creation of artificial reef habitats, however, other areas are likely to receive additional pressure as a result of displaced effort, (Marine Scotland, 2010c) which may negate the beneficial effects. Also, the potential beneficial effects of the infrastructure (and artificial habitat and ecological assemblages) may not be permanent, since they may be removed during decommissioning (Marine Scotland, 2010a).
Determining the sensitivity of different fishing activities is difficult since there is a lack of clarity over which fishing activities would be permitted within different sites, whether fishermen would be prepared to continue fishing even if they were allowed, and whether, if they were allowed, they would be able to carry on when maintenance vessels were actively working within arrays (Blyth-Skyrme, 2010a). All of these factors can influence future fisheries values.
Mobile (i.e. towed and drift) gear fishing vessels appear likely to be prohibited from fishing within offshore wind farm sites and so they can be assumed to have maximum sensitivity to developments. Cable routes may also represent significant impacts to these gears, where cables, cable trenches or snags resulting from trenching can act as barriers. Static gear vessels may be able to fish within offshore wind farm sites, although these vessels will be displaced from around turbines (usually 50m exclusion zones) and, potentially, from cable routes. Recent studies, particularly in the North East of England, indicate that fixed gear fishing (e.g. pots) and trawling by vessels under 10m can co-exist with offshore wind farms (Blyth-Skyrme, 2010a).
The most likely overall consequences of offshore wind farm development for commercial fisheries interests are generally considered to be negative, particularly for fishermen using mobile gear and for smaller vessels which do not always have the capability to relocate to other fishing grounds. Switching to other fishing methods is restricted by availability of capital, licences and quota. Fishermen whose income is currently gained from areas of potential offshore wind farm development may not be able to operate profitably after wind farm construction. (Mackinson et al., 2006).
4.2.2 Development of Scenarios
A number of potential impacts on commercial fishing have been identified which could affect profitability of the sector, namely:
- Effects on fish stocks or spawning and nursery grounds as a result of construction or operation of the short term options;
- Effects of displacement of fishing activity during construction and/or operation of the short term options; and
- Effects of increased steaming times to and from fishing grounds.
The impacts of OWF development on fish stocks remain uncertain. While some wind farm construction techniques (such as percussive piling of monopiles) have the potential to cause significant changes in underwater noise, there are no documented studies of long-term changes in the abundance or distribution of fish as a result of wind farm construction activity. Furthermore, mitigation measures may be required for short term option development to avoid adverse effects to Atlantic salmon, river and sea lamprey and allis and twaite shad which are all features of conservation importance within certain Special Areas of Conservation ( SAC) around Scotland ( ABPmer, 2011). On this basis it is unlikely that the residual underwater noise impacts would give rise to significant effects on target species for commercial fishermen.
Experiences with offshore wind development in English waters indicate that changes in water turbidity during construction and operation are limited both in magnitude and duration and within the range of values naturally encountered within the marine environment. No significant impacts on target species for commercial fishermen would therefore be anticipated.
A range of fish and a number of other species found in Scottish waters are potentially capable of responding to anthropogenic sources of EMF. Certain fish species, including common ones such as plaice, are understood to be both magnetically and electrically sensitive and a range of other species, notably cetaceans and many crustacea, to be magnetically sensitive. Most attention, however, has focused on elasmobranchs (sharks, skates and rays). The conclusion of most project-specific environmental impact assessments is that whilst it is possible that an interaction between these species and sub-sea cables could occur the result is unlikely to be of any significance at a population level ( DECC, 2009). A study by Gill et al (2009) assessed whether electromagnetic sensitive fish responded to EMFs with the characteristics and magnitude of EMF associated with offshore wind farm power cables. Although overall the study showed that some electrosensitive elasmobranchs responded to the presence of EMF that was of the type and intensity associated with sub-sea cables, the response was not predictable and did not always occur. When the response did occur it appeared to be species dependent and individual specific. There was no evidence to suggest any positive or negative effect on elasmobranchs of the EMF encountered and the authors stated that such effects could only be determined through a combination of monitoring at offshore wind farms and further experimental-based studies of specific behavioural responses that could indicate potential impacts. In soft sediment environments, it is likely that power cables will be buried below the sediment surface. This mitigation measures will significantly further reduce the exposure of fish to electromagnetic fields.
Short term option development also has the potential to lead to increases in local fish stocks, particularly where commercial fishing within arrays is restricted. However, it is difficult to quantify what if any additional benefit might be achieved and there is no clear evidence from existing wind farms to quantify such benefits.
Based on the above, this study has assumed that short term option development will not give rise to any significant or permanent negative or positive impacts on fish stocks.
The construction of short term options will result in the loss of and damage to fish spawning and nursery areas. The extent of such losses will be small relative to the overall size of wind farm arrays, being limited to the turbine footprints and some temporary damage along cable routes (Marine Scotland, 2010b). However, the potential displacement of towed gears within wind farm arrays and along cable routes may result in lower levels of bed disturbance in these areas and could potentially lead to improvements in the quality of spawning or nursery areas. Overall, this assessment has therefore assumed that impacts on spawning and nursery grounds will be neutral.
The short term options have the potential to cause vessels to detour around wind farm arrays, increasing steaming times to and from fishing grounds. Offshore wind farms should not form physical barriers to the movement of fishing vessels through the sites, however, additional costs in terms of time and fuel may result where fishermen are forced to steam further than normal to reach the far side of an offshore wind farm before fishing (Blyth-Skyrme, 2010a). Experiences with offshore wind farms in English waters suggests that commercial fishing vessels can generally transit through arrays without any significantly increased navigation risks. Indeed, the European Boating Association position statement states that there is no danger to a vessel under 24 metres in length navigating through the farm taking reasonable care. On this basis it has been assumed that effects on steaming times are negligible and the cost impacts are therefore insignificant.
For the purposes of this assessment, the principal cost impact that has been assessed therefore relates to the estimated cost impacts of fisheries displacement from the short term option arrays. Cost estimates have been developed for the three scenarios based on the assumptions identified in 22.
The future value of commercial fisheries is uncertain, particularly in the longer term. It is possible that reforms to the Common Fisheries Policy will lead to stock recovery for some species. For the purposes of this assessment it has been assumed that the value of first sale landings will remain relatively constant over time in real terms.
Table 22. Assumptions for scenarios for fisheries
High Impact Scenario
All forms of commercial fishing permanently displaced
Lost fisheries revenue is 2 x indicative total annual average landings value 2000-2009 (all gear types) for 50 years
Medium Impact Scenario
All mobile gear fisheries permanently displaced
Lost fisheries revenue is 1 x indicative annual average landings value 2000-2009 (mobile gears only) for 50 years
Low Impact Scenario
All mobile gear fisheries permanently displaced;
Lost fisheries revenue is 1 x indicative annual average landings value 2000-2009 (mobile gears only) for five years
The calculation of the landings values used in the cost estimate scenarios was based on the total annual landings catch data collated by the Marine Management Organisation ( MMO) by ICES rectangle. Annual data for the period 2000 to 2009 were used in the analysis and the average of these years was taken in order to arrive at an average total annual landings catch value for each ICES rectangle by vessel length, vessel nationality, fishing gear, species caught and port of landing.
The value of the total catch was assumed to apply equally to the whole ICES rectangle and this total value was reduced proportionally by the size of each short term option development area lying within the ICES rectangle(s). The value of the catch taken by mobile or static gear was calculated in order to produce the different cost estimates for the scenarios. The data for each ICES rectangle was assumed to apply equally to the whole rectangle since no data were available on the actual positions of the catch or of the location of fishing grounds within the ICES rectangle. This total value was then reduced proportionally by the size of each short term option development area lying within the ICES rectangle(s) irrespective of the mobility of the species.
The estimated value of catch within potential short-term options development areas that have been developed as part of this study are necessarily crude in assuming that fisheries value is evenly distributed across each ICES rectangle. In order to reflect the uncertainty in the distribution of fisheries value, the high impact scenario has used a multiplier of 2 x indicative total annual average landings value to represent a case where the displaced fisheries were relatively more valuable than the average across the ICES rectangle.
In the high and medium impact scenarios, it has been assumed that the cost impacts of fisheries displacement are permanent and that the affected fishermen are unable to relocate to alternative fishing grounds. In the low impact scenario, it has been assumed that over time, fishermen are able to make use of alternative fishing grounds such that the cost impact reduces to zero after 5 years.
4.2.3 Estimated Costs and Benefits
The estimated costs associated with each scenario for each region are presented in Table 23 below. No significant benefits have been identified. It is possible that some of these potential impacts may be offset by project level mitigation measures or, for example, the establishment of local fisheries funds. Such actions would represent transfers to fishermen from offshore wind developers. As these would be project level mitigation measures, and the result of site-specific negotiations between commercial parties, it is outwith the scope of this assessment to investigate them.
Table 23. Estimated annual loss of fisheries value as a result of displacement of commercial fisheries for the three scenarios
Low Impact 1
1 Costs applied only for a period of five years from construction
The main potential risks to aquaculture interests identified from consultation and the wider literature include:
- Environmental impacts to aquaculture species as a result of short term option construction, operation and decommissioning (changes in underwater noise, turbidity and water quality); and
- Displacement of existing or future aquaculture activity as a result of construction of short term options.
The draft SEA Environmental Report (Marine Scotland, 2010a) identified potential effects to wild fish arising from offshore wind farm development, including changes in underwater noise and water quality. The Information for Appropriate Assessment for the draft Plan for Offshore Wind Energy ( ABPmer, 2011) also identified similar potential effects to wild Atlantic salmon and identified additional mitigation measures that might need to be applied to short and medium-term options to avoid adverse effects to the integrity of SAC for which Atlantic salmon was a designated feature. Given that adequate mitigation measures will be required by law to protect wild Atlantic salmon, these measures would also be expected to protect farmed fish. Only one fish farm site is located within close proximity (<2km) to a short term option in the West Region. However, this site is a larval rearing unit and research facility and is located onshore in tanks. All other fish farm sites are located approximately 20km or more away (see Figure A3). Consultation responses to the draft Environmental Report did not identify any specific concerns in relation to the aquaculture sector (Marine Scotland, 2010b).
As noted above, there are no spatial overlaps between short term option development areas and existing aquaculture installations. Offshore aquaculture could become strategically important to the UK in the future due to a finite supply of available inshore sites (James and Slaski, 2006; Faber Maunsell Limited, 2008). Species that are already farmed in Scotland such as salmon as well as emerging species such as bass, cod and bream have the potential to be farmed in offshore areas. However its success will be dependant on improved safety and technological development (Faber Maunsell Limited, 2008; Defra, 2008).
However, it has also been proposed that offshore aquaculture and OWE could be co-managed in the same area (Blyth-Skyrme, 2010b and Mee, 2006). Combining offshore wind farming and marine aquaculture is an opportunity to share stakeholder resources and could lead to greater spatial efficiency in the offshore environment (Michler-Cieluch et al, 2009). While this could increase the income from the OWF lease, the technology is premature and may also create conflict with other users such as shipping by creating a navigation hazard. In addition to overcoming these constraints, the Crown Estate currently prohibits any other income earning activity by the OWFs in the leased area and so a change in law would also be required (Mee, 2006).
Based on the above, it is unlikely that significant negative or positive effects are likely to be experienced by the aquaculture sector as a result of the short term offshore wind development and no separate assessment of cost impacts to aquaculture interests has therefore been undertaken.
4.4 Shipping and Ports
Based on experience with existing offshore wind farm developments, short term option development has the potential to affect commercial shipping interests in a number of different ways. Potential negative effects include:
- Obstruction of commercial navigation routes resulting in:
- Increased steaming distance/time;
- Where ferries are affected, reduced turnaround time and increased cleaning costs;
- Potential long-term loss of revenue;
- Changes to existing navigational arrangements requiring additional buoyage;
- Interference with marine navigation radar systems;
- Displacement of recreational craft into commercial shipping lanes;
- Increased collision risk at sea; and
- Displacement of anchorages/fouling of anchors on cables.
Impacts to shipping may also have the potential to affect trade passing through ports, particularly in circumstances where impacts mean that shipping routes become less viable and shipping lines seek to identify alternative routes to another port.
A number of potential benefits may also arise, for example, commercial opportunities for construction and O&M vessels associated with wind farm construction and operation and port expansion to service construction and O&M activities.
Many of the potential negative effects can be mitigated by developers through careful siting of offshore wind farms, enhancements to marine radar systems, appropriate marking and lighting of developments and adequate cable burial. However, there are some ongoing negotiations from earlier offshore wind farm developments where commercial shipping companies maintain that developers have adversely affected navigation interests (Stewart Walker, Stewart Walker Associates, pers. comm. 22 Dec 2010), highlighting the commercial sensitivities of offshore wind farms on the shipping sector. Based upon consultation with the shipping industry, this is considered to be the area of greatest commercial concern to port/shipping operators and forms the core of this assessment.
Costs to provide appropriate navigational arrangements are relatively straightforward to estimate based on guidelines and existing case studies. Buoyage arrangements can also incorporate low cost mitigation measures to address navigation radar impacts, for example the incorporation of radar reflectors can enable radar users to 'tune out' radar clutter caused by offshore wind farms ( BWEA, 2007).
Available evidence indicates that recreational traffic can continue to safely navigate through offshore wind farms (see recreational boating section) and therefore the displacement of recreational traffic into commercial shipping lanes is likely to be minimal.
The short term options do not overlap with any existing anchorage areas. It is possible, but unlikely, that the cable routes selected by developers could transect anchorage areas. For the purposes of this assessment it has been assumed that short term option development will not affect any existing anchorage areas.
Detailed quantification of additional mitigation requirements to address collision risks or navigation radar impacts (e.g. infill radar) cannot be determined at this stage pending the completion of detailed navigation impact assessments. Based on experiences with R1/R2 developments in England, it is possible that no additional mitigation measures will be required to address these impacts, with the main concern and cost impact relating to potential diversion of vessels around wind farm structures.
4.4.2 Development of Scenarios
To develop the scenarios for the impact assessment a range of available evidence including direct consultation with key interest parties, information from existing offshore wind farm developments and research studies has been considered.
22.214.171.124 Additional steaming
Only limited data was available to estimate the effects upon shipping routes within each region as the detailed navigational risk assessments have not been undertaken for the offshore wind farm sites. The assessment had been based on waypoint ship density data as limited AIS data (which can provide more detail on vessel type) was available. The main interactions between shipping routes and the short term options have been identified as follows:
- North East Region - waypoint shipping data suggests that traffic to/from Cromarty/Inverness tends to follow the southern coast of the Moray Firth. The main north west/south east shipping route passes 10km to the north east of the short term development option. According to the same data, shipping movements within the proposed site boundary are less than 50 movements p.a. Taking into consideration the baseline data, there will be little if any impact upon commercial navigation resulting from short term development in the north east region.
- East Region:
- North East/South West bound traffic in the Forth Approaches - estimated number of vessels affected 991 p.a. 26 requiring a nominal increase in steaming distance of 4nm.
- East/West route out of Dundee -estimated number of vessels p.a. 2190 involving a nominal increase in steaming distance of 5nm.
- South West Region 27 - it has been estimated that approximately 100 vessels may need to divert by up to 2nm (inbound and outbound).
- West Region:
- Sound of Islay - estimated number of vessels affected p.a. 432 28 involving a nominal increase in steaming distance of 1nm.
- Sound of Jura - estimated number of vessels affected p.a. 432 29 involving a nominal increase in steaming distance of 1.25nm.
Based on these interactions, scenarios have been developed for the additional fuel costs based upon two generic vessel types based upon size, fuel consumption and manning costs as set out in Table 24 below. In the absence of reliable information on vessel types, and in order to provide a basis for estimating cost impacts, it has been assumed that the affected vessels in East and South West Regions are bulk cargo vessels but that in West Region, owing to depth constraints the affected vessels are coasters (i.e. small cargo vessels). Fuel consumption has been based upon data from Kemp (2008) who presented information on fuel consumption for a range of different vessel tonnages. Fuel consumption rates for a coaster were based on an assumed tonnage of 1600 tonnes and for a bulk coaster 5000 tonnes.
Table 24. Generic data used in calculating costs for additional steaming time
(tonnes per hr.)
(£s per hr.)
Assumed Cruising Speed
Bulk cargo vessel
These assumptions have been used to develop estimated costs associated with increased steaming distances. It should be noted that these costs are indicative and would need to be refined following completion of site specific risk assessments. The severity of effect of a diversion upon different carriers will vary according to their profit margins. By way of illustration, a 1nm diversion on a 200nm trip might represent a 0.5% increase in running costs. The minor nature of the additional steaming distances identified above mean that in most cases it is extremely unlikely that they would prejudice the trade associated with the route or lead to shipping lines seeking to transfer traffic to another port.
To reflect uncertainty in the detailed location and scale of short term development, and thus the implications for additional steaming requirements, the scenarios have used the assumptions set out in Table 25.
Table 25. Assumptions for scenarios for commercial shipping
High Impact Scenario
Diversion of all traffic around short term option areas; additional annual costs to shipping lines associated with increased steaming distances;
Medium Impact Scenario
Offshore wind developers exercise the 30% flexibility on licence area boundaries to change the shape of their sites to minimize shipping conflicts, reducing high scenario impact by 80%.
Low Impact Scenario
Reduced scale of development in East and West Regions and flexibility on licence area boundaries, all conflicts with shipping routes are avoided.
126.96.36.199 Additional navigational arrangements including buoyage
An estimate of buoyage has been made for the construction and operational phase based on the short term options on a regional basis. This estimate is based upon typical configurations for existing offshore wind farms using the IALA Recommendation O-139 on The Marking of Man-Made Offshore structures. The requirement is to mark all Significant Peripheral Structure ( SPS). A Significant Peripheral Structure ( SPS) is the 'corner' or other significant point on the periphery of the wind farm. It is assumed that the costs of these mitigation measures fall to developers, and would be contained within the capital expenditure costs of developing offshore wind farms. A recent Scottish renewables report (Scottish Renewables, 2010) estimated overall capital expenditure costs for STW and Round 3 offshore wind farms as being around £3.1m per MW installed. It is assumed that costs of buoyage would be included within these.
188.8.131.52 Military Interests
Agreement has been reached with the MOD to ensure that the short term wind development in East Region will not impede strategic defence navigational access into the Firth of Forth. In the future, the short term developments may reduce flexibility in the R3 Firth of Forth Array and an east-west corridor for maritime navigation will need to be retained (Defence Estates Safeguarding, 2010). It is understood that both developer aspirations in terms of turbine spacing/density and Shipping/ MOD requirements for maintained sea routes can be satisfied by the existing development plans , although vessels will need to manoeuvre around arrays.
Short term option areas within West Region overlap within the Earadale Practice and Exercise Area ( PEXA). Given the proximity of Faslane submarine base, the area is likely to be occasionally used by submarines transiting or on training sorties. The developer should be able to proceed with the desired turbine density within the site but Defence Estates Safeguarding has made representations concerning the orientation of the turbine spacing and the accuracy of charting the turbines (Jon Wilson, Defence Estates Safeguarding, pers. comm. 6 Jan, 2011).
4.4.3 Potential Benefits to Shipping from Wind Farm Developments
There are a number of potential benefits to the shipping sector and to ports associated with offshore wind farm development. The construction and maintenance of offshore wind farms requires support from suitable vessels including barges to transport and install structures, cable laying vessels and maintenance vessels. Offshore wind farm development also requires suitable port facilities to act as supply bases during construction and operation. The potential benefits to the supply chain associated with short term option development are described in Section 4.3 and has not been quantified here.
There may also be other potential opportunities for the shipping sector. For example, P&O Shipping has made provisional plans to exploit the market opportunities provided by the expansion in the offshore wind farm construction by the provision of floating hotels (floatels) that would serve as food and accommodation bases for workers during construction at some sites and potentially as operational maintenance bases, thereafter (Stewart Walker, Stewart Walker Associates, 22 Dec 2010).
4.4.4 Estimation of Costs and Benefits
The estimated costs associated with each scenario for each region are presented in Table 26 below. No significant benefits have been identified. The most significant costs are estimated to occur in East Region owing to the higher densities of shipping and larger average vessel size.
Table 26. Estimated annual costs associated with additional steaming times
184.108.40.206 Civil aviation
Based on previous experiences with offshore wind farm development, the construction and operation of OWF has the potential to cause a hazard to civil aviation through:
- Interference with both en-route and approach civilian navigation radar systems;
- Increased risk of aircraft collision as a result of the above; and
- Height obstruction of commercial navigation routes.
However, we also note that the development of offshore wind farms may provide commercial benefits for the aviation sector in terms of increased passenger numbers to local airports as a result of increased economic activity associated with wind farm construction and operation. It is not possible at present to quantify these benefits.
220.127.116.11 Defence aviation
The principal interest of the MOD with respect to the draft plan published relates to the potential for offshore wind turbines to obstruct or cause interference to the operation of both air traffic and air defence radar systems (Defence Estates Safeguarding, 2010).
The MOD response to the SEA noted that whilst Air Traffic Control radars at aerodromes had been recognised in the SEA, precision approach radar systems at military aerodromes, MOD air traffic control facilities not located at aerodromes as well as Air Defence and Meteorological radar sites had not been taken into account (Defence Estates Safeguarding, 2010). These facilities also have the potential to be affected by offshore wind farm development.
In some areas, the construction and operation of short term OWF has the potential to interfere with military operations within or occasionally outside of PEXAs.
4.5.2 Development of Scenarios
Based on previous experiences with offshore wind farm developments, the potential related economic impacts resulting from both interaction with civilian and military aviation include:
- The need to provide radar mitigation that may range from site-specific blank and fill (with potentially the need to install a new radar to strategic initiatives such as those being pursued through the Aviation Investment Fund Company Ltd;
- Planning delays associated with the provision of radar mitigation;
- Additional track miles for aircraft/helicopters owing to physical interference or radar clutter;
- Change to and or reduction in the scale/output of wind farm projects to mitigate for physical obstruction caused to aircraft; and
- In extreme cases, cancellation of wind farm developments owing to insurmountable problems.
Strategic solutions are being pursued to provide mitigation for en-route aircraft control in controlled airspace above 5500ft, and in relation to low-level radar that informs ATC in airport controlled airspace. It is possible that short-term option developers may contribute to the funding of these strategic solutions, or for regional/local solutions where necessary. For the purposes of this assessment, it has been assumed that these costs are included within the overall estimated capital cost of offshore wind developments, which have been estimated at being around £3.1m per MW installed (Scottish Renewables, 2010). As per other mitigation measures that form a part of capital costs of wind farm development, these have not been considered further in the analysis.
A range of potential further region specific issues are discussed below.
18.104.22.168 North East Region
Initial consultation with NATS has highlighted that the Beatrice OWF will be visible to the Allanshill Primary Radar located near Fraserburgh. In addition to this the NATS North Sea Helicopter Advisory Route W4D (Aberdeen to Wick) also routes directly over the site. Consequently, NATS has suggested that the extent of the potential impacts will require further assessment ( ERM, 2010).
It is assumed that helicopters using the Aberdeen - Wick Advisory Route will not be routinely affected by the construction of the short term option and will maintain a safe height above the turbines. However, in the event of inclement meteorological conditions, helicopters may not be able to overfly Beatrice and may need to divert 7nm on both the inbound and outbound route. Such conditions are assumed to affect 10% flights and the associated costs in terms of additional fuel/time/other resources are considered to be minor and not significant at Plan level.
The short term option lies approximately 65km and 80km respectively of the RAF Air bases of Kinloss and Lossiemouth. As noted previously, RAF Kinloss is scheduled to close in March 2011 and impact on Lossiemouth is not envisaged due to the distance from the proposed development. Its location within the Moray Firth exercise areas that are used by the RAF as low flying practice areas, firing and bombing ranges. However, the presence of air traffic control radars (including Precision Approach Radars ( PAR) has not been taken into consideration and may therefore be a relevant constraining factor in the progression of the short term development. Whilst the location of the Air Defence Radar at RAF Buchan has been recognised the presence of the nearby Hill of Dudwick Meteorological Weather Radar has not been identified and may therefore be a relevant constraining factor in the progression of the sites identified (Defence Estates Safeguarding, 2010).
The full impact upon airspace and radar of short term OWFs in the North East region is being assessed as part of the Beatrice EIA through consultation with the MODCAA and other stakeholders ( ERM, 2010).
22.214.171.124 East Region
National Air Traffic Services ( NATS) have confirmed that there will be no impact upon civil aviation radar operations by the proposed Forth Array scheme (Fred Olsen Renewables, 2010). However NATS remit embraces en route radar facilities only. The Civil Aviation Authority ( CAA) has noted that, as a result of needing to lower their operating altitude in inclement meteorological conditions, helicopters may not be able to overfly wind farm developments, and thus would be forced to alter their track to go laterally around the sites, resulting in additional track miles, costs and emissions (Civil Aviation Authority, 2010).
While it is understood that there are no direct objections from MOD to short term developments in East Region it is evident from review of the correspondence that the new developments will constitute an additional constraint that will reduce the flexibility in mitigating radar interference for the medium term options. While account has been taken of the PAR, the scoping undertaken, to date, would suggest that there could be further issues affecting military radar, e.g. the primary surveillance radar ( PSR) for RAF Leuchars affecting a large portion of low level (<80m) coverage for RAF Leuchars (Figure 26). It is not possible to estimate costs of potential mitigation measures, pending more detailed project level assessment. It is possible that the potential improvements that may be required for low level radar to facilitate civilian aircraft may also address some of the issues for military aircraft.
Figure 26. Military practice areas and RAF Leuchars in relation to Neart na Gaoithe offshore wind farm
(Source: Mainstream Renewable Power, 2009)
126.96.36.199 South West Region
No specific civil aviation issues for the South West region were identified from the review of the literature and consultation. The MOD Air Traffic Radar facility at West Freugh has not been taken into consideration and may therefore be a relevant constraining factor in the progression of the sites identified in this region (Defence Estates Safeguarding, 2010).
188.8.131.52 West Region
Campbeltown does not have a civilian radar system (Anne Phillips, HIAL, pers. comm. 10 Jan. 2011); in view of the close proximity of one of the short term options to the runway approach, aircraft using the airport will be physically obstructed by the proposed layout of the OWF and HIAL have written to SSE Renewables advising them of which turbines interfere with aircraft using the airport. Modifications to the layout of the site may be achievable within the overall flexibility provided by the lease (the lease footprint can be varied by up to 30% by agreement) without reducing installed capacity.
None of the short term options are expected to cause low level radar clutter issues as Prestwick is still in excess of 75km away from the nearest of the short term options.
Based upon feedback obtained, to date, there is no significant impact from short term wind farm developments upon military aviation/radar in the west region; military interests likely to be affected by these developments relate more to submarine operations (see Section 4.6.2).
4.5.3 Estimation of Costs and Benefits
It is possible that short-term option developers may need to contribute to strategic radar solutions within each region. It has been assumed that these costs are incorporated within the estimated capital cost of around £3.1m per MW installed capacity.
No specific costs to civil or military aviation interests have been quantified, although the regional analysis has identified some potential issues that may need to be addressed at project level. There is likely to be some scope at project level to mitigate impacts where necessary.
4.6 Wave and Tidal Energy Development
Short term option development has the potential to affect wave and tidal development through competition for space (in areas of resource overlap) and competition for electricity supply or through changes in coastal processes which reduce the suitability of wave and tidal resources. Wave and tidal energy is up to 10 years behind wind energy in development, making it difficult to asses the economic effects of OWF development on possible future wave and tidal renewable energy development.
While the locations for short term option development in West Region overlap with areas of potential future wave resource, it is unlikely that such areas will be a priority for deployment of wave converters. The extensive areas of wave resource off Scotland's North and West coasts mean that the loss of small areas of potential future wave resource for offshore wind development is unlikely to significantly constrain development of the industry.
The short term options do not overlap with the primary areas for tidal stream deployment, although the Islay Array is located just to the north of the main tidal stream resource off Islay. It is unlikely that short term option development will significantly affect the suitability of existing tidal stream resources.
It is possible that investment in offshore wind development may affect the pace of development and implementation of wave and tidal development in the short term within the context of a competitive energy supply sector. However, this should not prevent wave and tidal technologies from contributing to the energy supply mix in the future alongside offshore wind.
For the purposes of this assessment, it has been assumed that short term options development will not give rise to any significant costs or benefits for wave or tidal stream energy interests.
4.7 Cables and Pipelines
Short term options development has the potential to affect existing cable and pipeline interests. While site selection and planning has avoided interaction with existing cables and pipelines (Figure A11), it is possible that export cable routes could cross over some existing cables. While this does not pose any major issues during the construction phase, UKCPC have indicated their concern that the general proliferation of cables in the marine environment, particularly as a result of offshore wind development may increase the costs of maintaining existing cables in the future. In particular, where there are multiple cables in close proximity, it is likely to become more difficult to retrieve cables for maintenance. Furthermore, where maintenance is required in the vicinity of cable crossovers, this is likely to preclude maintenance techniques which involve cable retrieval. Instead, more expensive maintenance methods will be required, relying on the use of divers or ROVs. These methods will be significantly more expensive than traditional cable maintenance techniques.
While ease of maintenance is a general concern of the cables industry, UKCPC has indicated that it has no specific concerns in relation to the short term option developments (Richard Hill, UKCPC, pers. comm. 18 Jan 2011) and therefore it has been assumed that there will be no significant costs to existing cables and pipelines associated with short term options development.
In relation to pipelines, 'Interconnector 2' runs just 50 m to the south-east of the proposed site for the Wigtown Bay offshore wind farm. As described in Section 3.8, this pipeline provides gas to the Republic of Ireland and the Isle of Man. 'Interconnector 1' however runs 7 km through the middle of the site before continuing on to Dublin. Issues with these pipelines would be the subject of site-specific discussions, and as such are outwith the scope of this assessment.
Oil and Gas UK provide an example of pipeline constraints with a Round 2 wind farm site in England (Mick Borwell, Oil and Gas UK, pers. comm. 21 Jan 2011). Maintenance barges for pipeline work are generally anchored and require a nominal working space of 500 m either side of the pipeline. A similar issue with the proposed Triton Knoll offshore wind farm development resulted in the site being split into two discrete regions either side of a 1 km buffer zone for three existing sub-sea pipelines ( IPC, 2010). Comments from the Health and Safety Executive on Triton Knoll highlighted the need to ensure that the proposed development did not adversely interact with major accident hazard pipelines ( MAHPs) ( IPC, 2010). Exclusion zones for pipelines tend to be agreed at a site-specific level and may be less or more than the distance cited in the Triton Knoll case.
For the purposes of this assessment, it has been assumed that short term options development will not give rise to any significant national or regional costs or benefits for cables and pipelines interests.
4.8 Recreational Boating
Based on previous experiences with offshore wind farm developments, the construction and operation of offshore wind farms has the potential to negatively impact on recreational boating activities through:
- Increased collision risk with rotor blades and/or sub-surface structures particularly in narrow channels with strong tidal flows 30;
- Loss or alteration of 'essential routes' into sheltered harbours and anchorages used for shelter during poor weather conditions;
- Loss of cruising routes or displacement of cruising routes into commercial routes;
- Altered recreational boating vessel transit through wind farm areas incurring additional fuel costs;
- Racing/sailing areas relocated;
- A reduction in recreational boating activity related to a perceived loss of scenic quality of the seascape. SEA Environmental Report consultation responses 31 particularly highlighted these issues for development in the West Region; and
- Reduced levels of investment in marinas and recreational boating infrastructure in response to the uncertainty created by short term option development.
Some of the risks posed by offshore wind development can be mitigated by developers through careful siting of offshore wind farms and appropriate marking and lighting of developments. The RYA Position Statement on minimising adverse impacts of marine renewables on recreational sailing ( RYA, 2009) suggested that good design may mitigate against some of the anticipated visual impacts.
No racing or sailing areas are likely to be affected within any of the regions and therefore no impacts on these facilities are anticipated.
The European Boating Association ( EBA) position statement states that 'there is no danger to a vessel under 24 metres in length navigating through the farm taking reasonable care'. During stakeholder consultations, the RYA concurred with the EBA position statement, that it was safe for vessels under 24m to navigate through offshore wind farms once construction was complete and that there was no need to avoid passing through them (Caroline Price, RYA, pers. comm. 17 Jan 2011) 32. A questionnaire undertaken by the RYA as part of a study into recreational boating in wind farm strategic areas revealed that the perception of the majority of sailors was that navigating through a wind farm, in which turbines would be 500-700m apart, is feasible with 75% of respondents stating that in favourable conditions, they did not anticipate a problem navigating through with only 14% stating that they would not navigate through in any conditions ( RYA, 2004). However, the RYA highlighted that since that survey in 2004, when offshore wind farms were relatively new, people now have more experience of sailing through offshore wind farms and concerns have shifted from navigating through individual offshore wind farms to the challenges related to navigating through areas of coastline (e.g. the east coast of England) with numerous offshore wind farm developments and shipping lanes (Caroline Price, RYA, pers. comm. 17 Jan 2011).
Anecdotal evidence from England suggested that while members had expressed that cruising may be "more challenging" due to the presence of offshore wind farms, the RYA had not heard members state that they would not go sailing in an area because of offshore wind farms. Many people undertake recreational boating activity in a specific area which they know well and, in general, do not change this behaviour but instead adapt to any changes that occur within that area (Caroline Price, RYA, pers. comm. 17 Jan 2011).
As such, based on this limited evidence from the effect of offshore wind farms in England, it has been assumed that there will be no significant negative impacts relating to collision risk/navigation or changes in recreational boating activity levels related to perceived reductions in seascape quality. The latter assumption has been made with low confidence, based on anecdotal evidence that offshore wind farms in England have not altered the distribution of recreational boating activities whilst recognising that certain regions in Scotland, may be more sensitive to seascape-related impacts, for example, due to the 'wilderness and uncluttered scenery' being a 'selling point' for the recreational boating sector in Scotland (Mike Balmforth, SBA, pers. comm. 18 Jan 2011). It should also be noted that these assumptions are made using 'national level' information (i.e. from the ' UK Recreational Boating Atlas') and not from detailed assessment of local cruising routes, which were not available at the time of assessment, but which were highlighted in local stakeholder workshops. As such, project level assessments will need to take such local cruising routes into consideration.
In relation to the loss of essential routes into anchorage points, examination of the UK Recreational Boating Atlas suggested that no cruising routes into anchorage points passed through any of the short term developments options in the South West, East or North East Regions. Consultation with RYA Scotland identified one existing cruising route in the West Region up the west coast of Kintyre that the organisation considered essential from a safety point of view. If vessels 'following' 33 the cruising route were unable to navigate through the offshore wind farm development (e.g. due to adverse weather conditions), safety issues may arise, especially as once committed to this route (in either direction), it is difficult to turn back. The route in question is frequently taken to avoid overfalls and other inshore hazards in the area (Graham Russell, RYA Scotland, pers. comm. 18 Jan 2011)., For this assessment it has been assumed that no loss or alteration of essential routes will occur, based on the position of recreational boating organisations that there are no need for exclusion zones for small (<24m) vessels from offshore wind farms, however a potential safety issue in relation to an essential cruising route in the West Region has been noted.
No potentially significant positive effects on recreational boating interests have been identified.
4.8.2 Development of Scenarios
Within the analysis, potential impacts related to additional fuel costs have been estimated. However, for the low and medium impact scenarios, no costs have been identified based on the assumptions that there are no significant navigational issues associated with cruising through offshore wind farms for vessels under 24m, no decrease in recreational boating activity arising from loss of 'scenic quality', and only temporary disruption to general sailing areas during construction (Table 27).
For the high impact scenario, additional costs have been assumed to be restricted to additional fuel costs for a small proportion of vessels which choose to divert around wind farm option areas which are intersected by recreational cruising routes (Table 27). No detailed information on the number of vessels passing along cruising routes, the proportion of vessels travelling under motor 34 or a more recent estimate of the number of vessels which may choose to deviate around an offshore wind farm was available. Hence, for the purposes of this assessment, it was only possible to calculate the additional fuel costs for a hypothetical number of vessels which may deviate around the offshore wind farms, in this instance chosen as 1,000 boats. Such a value is likely to represent relatively conservative number for vessels that would choose to divert around a wind farm in normal circumstances, based on experiences with offshore windfarms in English waters.
Table 27. Assumptions for scenarios for recreational boating
High Impact Scenario
1,000 recreational vessels per annum choose to divert around short term option areas; additional annual costs to associated with increased steaming distances.
Medium Impact Scenario
Vessel transit through offshore wind farms is unaffected. No additional costs incurred.
Low Impact Scenario
Vessel transit through offshore wind farms is unaffected. No additional costs incurred.
In order to calculate the additional fuel costs for vessels choosing to deviate around offshore wind farms, the cost of marine diesel was taken as £0.96 per litre. The mileage per litre for vessels under motor depends on the size and speed of the vessel in question, ranging from about 13-63litres/hour 35. For the purposes of this assessment, for a 'generic' averaged sized boat, a fuel consumption of 40litres/hour for a boat travelling at 20 knots has been assessed. At this speed, the mileage was calculated as approximately 1km/litre.
An indicative diversion route length was estimated within each region by measuring the difference between a 'current' cruising route through an array and an alternative cruising route. Within each region, an indicative example of a diversion distance around an array(s) was estimated. In regions where cruising routes intersected more than one array, the likely largest diversion distance (assessed visually) was measured and used as the value for that specific region (e.g. the diversion distance around the Solway Firth was measured in the South West Region). The exception to this was in the East Region, where the distance to divert a cruising route which intersected both the Neart na Gaoithe and Forth Arrays was calculated. Where more than one cruising route intersected an array, the longest route through the array (assessed visually) was measured and an alternative route created (i.e. the 'diversion length' was calculated for the longest section of cruising route intersecting any given array). It must be noted that these alternative cruising routes were not devised to take into account of other natural or man-made navigational hazards (i.e. they may not represent realistic deviation routes) and as such only represent indicative values of potential deviation distances.
Using this method, indicative estimates of the cost of diverting around an offshore wind farm in each region was estimated for 1,000 boats per annum as the diversion distance (km) x price of marine diesel/litre.
The indicative diversion distance per region is shown below:
- West: 10km (around Kintyre Array);
- South West: 7km (around Solway Firth Array);
- East: 14km (around the Neart na Gaoithe and Forth Arrays); and
- North East: 3km (around the Beatrice Array).
Because of the absence of data in this area, and the quantity of assumptions that have needed to be made to develop cost estimates, there is a high degree of uncertainty around the estimated cost impacts. However, all the estimated costs are very small, and it is not believed that these estimates provide a realistic indication. For the costs to be more significant, the number of vessels deviating around the short term option arrays would need to be several orders of magnitude greater than estimated. Based on the available evidence from England, this seems unlikely.
4.8.3 Estimation of Costs and Benefits
The estimated costs associated with each scenario for each region are presented in Table 28 below. The most significant costs are estimated to occur in East Region reflecting the potentially greater diversion distances that might be incurred.
Table 28. Estimated annual costs associated with additional steaming times
4.9 Recreational Angling
Based on previous experiences of offshore wind farm development, the construction and operation of offshore wind farms can have a range of potential impacts on recreational angling including both positive and negative impacts which can give rise to economic impacts on the supply chain (boat hire, fishing tackle sops, bait sales, associated spend on accommodation etc). Potential negative impacts include:
- Displacement of boat anglers from, or decreased access to, traditional recreational sea angling areas within wind farms; 36
- Temporary exclusion of shore anglers during cable laying on the shore;
- Impacts on fish stocks during construction and/or operation of offshore wind facilities as a result of impacts to feeding, breeding and/or migration of species of angling interest (e.g. through increased noise, vibration, turbidity or electromagnetic fields) ( SSACN consultation response). 37
The construction and operation of offshore wind farms has the potential to positively impact on recreational angling through: 38
- Additional sea angling opportunities created by offshore wind farms through:
- Increased land-based infrastructure (e.g. all weather harbours, all tide slipways, boat storage areas) arising from the construction and operation of wind farms designed to accommodate and made available to sea anglers;
- Provision of mooring buoys for recreational sea angling within wind farm;
- New structures within, and exclusion zones around, the offshore wind farms provide suitable habitat for, and allow the recovery of stocks levels of, recreational sea angling species of interest. New structures and/or cable protection such as rock armour, at the cable landfall sites may provide suitable habitat for angling species of interest and hence create new or improved opportunities for shore angling; and
- Possible development of new sea angling fisheries in areas which are currently void of targetable fish and/or recovery of areas where sea angling has been absent due to the depletion of the target fish species . Possible development of new sea angling areas in response to displacement or restriction to sea angling in wind farms.
4.9.2 Development of Scenarios
To develop the scenarios for the impact assessment we have taken account of a range of available evidence including information from existing offshore wind farm developments and research studies.
The impacts of offshore wind farms on fish stocks remain uncertain to some extent. The issues have been described in Section 4.4 in relation to commercial fish stocks. The evaluation concluded that short term option development should not cause any significant impacts on fish stocks, assuming appropriate mitigation measures were implemented.
While some restrictions on shore fishing could be imposed during construction of the cable landfall, such restrictions would be local to the works and temporary. Placement of rock armour at the landfall could improve shore fishing opportunities, but this is unlikely to provide a particularly significant benefit as the area of shoreline affected would be very small. The study has therefore assumed that impacts on shore fishing would therefore be negligible.
The other potential benefits from short term option development (improved shore-side facilities, provision of moorings within offshore wind farms and development of new fisheries) are all very uncertain and have all therefore been assumed to be negligible.
The development of the scenarios has focused on the potential impact of displacement of recreational fishing activity from within short term option developments (Table 29) and the economic consequences for expenditure associated with recreational angling.
Table 29. Assumptions for scenarios for recreational angling
High Impact Scenario
All boat-based recreational fishing activity within wind farm arrays located within 6nm of the coast 39 ceases and is not offset by increased levels of activity elsewhere within the region or Scotland.
Medium Impact Scenario
It has been assumed that costs will be 20% of the high estimate scenario on the basis that the total value of recreational fishing activity within development areas is unlikely to be lost completely to the region or Scotland and it is unlikely that exclusion policies would apply to the full extent of all wind farms.
Low Impact Scenario
No significant displacement of recreational fishing activity occurs. This is based on experiences with some English offshore wind farms where anchoring exclusions are limited to 50m exclusion zone around each turbine tower which represents a very small proportion of each wind farm array.
In the high impact scenario, it has been assumed that all boat-based recreational fishing activity within wind farm arrays located within 6nm of the coast ceases and is not offset by increased levels of activity elsewhere within the region. For those regions within which short term development is proposed within 6nm of the coast (West and South West Regions), the area of development which falls within 6nm was measured and calculated as a percentage of the total area of coastal water within 6nm for the appropriate region. The proposed short-term options in East and North East Regions are located beyond 6nm and it has therefore been assumed that recreational angling impacts in these regions will be negligible. Based on the estimates of total annual sea angling expenditure within different regions in Scotland from Radford et al (2009) (see sections 3.10.1 to 3.10.3), the estimated loss of sea angling expenditure that would arise from the displacement of boat angling from areas of offshore wind farms within 6nm could be calculated as:
(Area of development within 6nm/regional area within 6nm)
x expenditure on boat-based angling in region
These calculations assume that the regional sea angling expenditure values presented in Radford et al (2009) relate to sea angling undertaken within 6nm of the coastline and that boat-based sea angling is spatially evenly distributed within the area contained between the coastline and 6nm.
In both the medium and high impact scenarios, it has been assumed that the displaced activity is lost from Scotland on the basis that a high proportion of anglers are visitors from elsewhere in the UK and may no longer choose to visit Scotland (Radford et al, 2009). However, it is recognised that this is likely to be an oversimplification and that some activity will simply be displaced within regions or within Scotland as a whole.
4.9.3 Estimation of Costs and Benefits
Estimates of costs associated with the different scenarios are presented in Table 30 below. No significant benefits have been identified. The main costs are estimated to occur in South-West and West Regions.
Table 30. Estimated reductions in expenditure on recreational angling
4.10 Surfing, Windsurfing and Kayaking
Based on previous experiences with offshore wind farm developments, the main potential impacts of concern for surfing and windsurfing associated with short term option development include:
- Effects on the quality of the wave for surfing (wave height, period and direction); and
- The visual impact of offshore wind development on the seascape setting for surfing and windsurfing.
Surfing and windsurfing largely take place close to shore and therefore generally do not occur within the footprint of wind farm arrays. We were unable to source information on the impacts on sea-kayaking, but given that most kayakers stay within several hundred metres of the shore (based on informal discussions with experienced kayakers), it is considered unlikely that they will be particularly affected by offshore wind farms.
SAS (2010) note that when 'valuing' the worth of a wave, the number of surfers that would be affected if the wave was destroyed or degraded needs to be considered. In general, the value of a wave increases as a function of the number of people that surf it, where a wave is probably worth more if it is in accessible part of the UK with a regular surfing population nearby compared to if it is in a less accessible area. However, many surfers are willing to travel large distances to undertake surfing at good quality spots (Lazorow, 2009). Therefore, high quality waves located in remote areas could bring economic benefits to a rural area through travel, accommodation and subsidence expenditure of visiting surfers.
Surfing wave quality is fundamental to the economic value of surfing ( SAS, 2009). The principle impacts of renewable energy developments on surfing wave resources concern potential changes to the wave climate (i.e. wave height, period and direction) particularly at the coast, as well as changes to sedimentary processes (transport and deposition) and water clarity (turbidity) during OWF construction and operation. For example, as a wave passes through an OWF development, there is potential for energy to be blocked and re-directed by the renewable device structures ( SAS, 2009), impacting on wave height and wave angle.
Good evidence of the changes in wave height and direction is available from existing wind farm sites. For example, as part of the EIA for the Round 1 Burbo OWF development in Liverpool Bay (shortest distance from array boundary to land about 3.37nm/6.2km), ABPmer (2002a) undertook modelling to investigate the near- and far-field changes in wave regime on waves passing through 30 turbine structures of 4m diameter. The model predicted that in general the effects were related to small reductions in wave height (typically < 0.1m, equivalent to about a 3% reduction in wave height) and that down-drift of the wind farm the influence on the near-field wave climate quickly dissipated such that the differences in wave climate became minimal (<0.02m).
Similarly, a model to assess the influence of a proposed development at Scarweather Sands (30 turbines, assumed 'maximum impact scenario' of a gravity base 28mx28mx3m height supporting a 5.6m diameter turbine mast; shortest distance from array boundary to land about 5.7km ) on the baseline wave regime revealed that the proposed development would generally cause localised changes to the 'near-field' area ( ABPmer, 2002b). These effects included small changes in wave height (falling within the range of 0-5% change in baseline wave conditions) immediately in the lee of individual structures, but without significant 'far-field' effects. The report stated that natural changes in the morphology of Scarweather Sands were likely to cause greater degrees of variation in the far-field wave regime. The results also indicated that the OWF effect on regional sediment pathways (erosion and deposition) were negligible. Further modelling of the effects of the Scarweather Sands Offshore Wind Farm were undertaken in 2003 ( ABPmer, 2003), including assessment of the effects of the development on wave height at different stages of the tidal cycle and the effect of the development on the swell component of the wave climate to assess the impact on the surf in Rest Bay. The results showed that the greatest effect on wave climate occurred at the time of high water and supported the previous findings that the development would have no significant effect on the wave climate at the shoreline.
A study of changes to the near and far-field wave regime at Scroby Sands OWF (30 monopile wind turbines, 4.2m in diameter; shortest distance from array boundary to land about 0.93nm/1.75km) using field measurement techniques and modelling showed that the effects arising from a monopole-based wind farm was a reduction in wave height of 2-5% in the immediate vicinity of the wind farm with this effect decreasing rapidly with distance from the wind farm such that wave climate reached background values within a distance of 2-3 turbine spacings (Cefas, 2005). It was concluded that the wave diffraction (changes to incoming wave direction) and interference effects arising from monopole arrays are negligible and, by inference, nearshore effects were also likely to be negligible.
Evidence from existing wind farm developments therefore indicates that there have been no significant changes in wave quality at the shoreline as a result of these developments. A concern raised by stakeholders is that OWFs proposed under future leasing are larger than existing offshore wind farms (e.g. numbers of turbines, diameters of foundations) and hence the diffraction and wave height effects may be greater. For example, RPS (2005) found that the magnitude of far-field impacts from the London Array OWF on wave climate were related to foundation type and the state of the tide with the greatest impact (reduced wave height of up to 5cm at the north Kent coast at times of high water during peak ebb tides) was predicted for Gravity Base Structure ( GBS) foundations. Nevertheless it remains unlikely that future developments will significantly affect wave quality at the shoreline and the cost impact is therefore considered to be negligible.
The effect of the visual impact of offshore wind development on the attractiveness of locations for surfing and windsurfing is uncertain. SAS (2009) notes that wave quality is the most important factor affecting the economic value of surfing. However, it is possible that the overall attractiveness of an area for tourism could be affected by visual impact and in turn this could reduce surfing or windsurfing activity undertaken as part of wider tourism activity. This issue is discussed further in the tourism impact assessment and no separate cost estimate is provided here.
A perceived reduction in the attractiveness of an area as a result of offshore wind farm development has the potential to affect decisions on the suitability of specific locations for hosting surfing or windsurfing events. However, the primary reason that locations around Scotland are chosen for such events are the wind and wave conditions. Given that short term option development is unlikely to affect these conditions, it is unlikely that future hosting of specific events would be affected.
On this basis, it is unlikely that any significant national or regional costs will be incurred by surfing or windsurfing interests as a result of short term option development and no cost estimates have been included for any of the scenarios.
The construction and operation of offshore wind farms can have a range of potential impacts on tourism including both positive and negative impacts based on information from existing offshore and onshore wind farm developments.
Potential negative impacts on tourism may occur through:
- Visual effects on the landscape and seascape 40 deterring visitors to an area or deterring tourism investment;
- Disturbance or injury to coastal or marine wildlife interests (e.g. for wildlife watching) during construction or operation of the wind farm; and
- Disruption to site access for tourism operations.
Impacts on tourism from visual effects may arise due to a visitor's a perceived reduction in the attractiveness of 'quality' of the landscape (i.e. the important feature attracting tourists) due to the presence of an offshore wind farm, which may potentially result in reduced prices for tourism services and/or reduced numbers of tourists. For example, concern was raised in several consultation responses to the Offshore Wind Energy Draft Plan and SEA regarding highly sensitive seascapes in the West and South West Regions and the potential for development to have significant adverse impacts on the scenic amenity during construction and operation of the offshore wind farm 41.
In addition to general impacts on tourism numbers, there is the potential for offshore wind farm development to adversely affect investment in new resort development in circumstances, where such development is promoted on the basis of a rural location and uncluttered seascapes, for example, golfing or watersports resorts.
Potential positive impacts on tourism may occur through:
- Visual effects on landscape and seascape during operation creating tourism opportunities, providing add-on benefits to existing wildlife excursions and attracting visitors to an area.
4.11.2 Development of Scenarios
To develop the scenarios for the impact assessment we have taken account of a range of available evidence including information from existing offshore wind farm developments and relevant studies relating to onshore wind farms.
A survey by Riddington et al (2008) estimates the impacts of onshore wind farm development on tourism expenditure in Scotland. Based on this research, the estimated potential reductions in general expenditure of tourists in four case study areas are shown in Table 31.The study suggests that the impact from onshore wind farms on visitors' intentions to return to the area is likely to be low. The vast majority of visitors (93-99%) who had seen a wind farm suggested that the experience would not have any effect; in fact there were some tourists for whom the experience increased the likelihood of a return visit rather than decreasing it. In the absence of a comparable study for offshore wind development, the findings from the onshore study have been used to estimate impacts associated with offshore wind farms, although it is recognised that the findings from onshore studies may not be perfectly transferable.
Table 31. Estimated reduction in general expenditure of tourists by area
Study Areas from Riddington et al (2008)
Caithness and Sutherland
Stirling, Perth & Kinross
The Scottish Borders
Dumfries & Galloway
* The number of tourists that may come into contact with any of the projects that were built, permitted or in the process of applying for permission within the planning system.
Recent studies in Denmark by Ladenburg & Dubgaard (2009) & Ladenburg (2010) suggested that people who use the coastal zone (e.g. anglers, recreational boaters) significantly perceive the visual impacts of offshore wind farms to be more negative compared to people who do not use the coastal area for those specific purposes. The results also indicated that respondents who visit the beach on a frequent basis also have stronger preferences for reducing visual disamenities (i.e. reducing visual impacts) when compared to less frequent visitors. The results suggested that the recreational value of the coastal use is potentially jeopardised by visual impacts from the offshore wind farms in the Danish studies, which the authors described as being "not located at [a] relatively large distance from the shore". The authors concluded that potential reductions in capital cost (investment, construction and running costs) by locating OWFs at relatively closer distances to the shore might be outweighed by the reduction in visual amenity benefits in coastal areas with a large recreational activity. As such, the optimal location (i.e. distance from the shore) of offshore wind farms might be further away from the coast in areas with a high level of recreational activities compared to coastal areas with relatively little recreational activity.
The 'Keep Wigtown Bay Natural' response to the Offshore Wind SEA consultation 42 highlights a survey undertaken along the Wigtown Bay coastline in August 2010, which asked 79 visitors what had attracted them to the area and how likely they were to return in the future. Of the responses, 44% included 'scenery' as a reason they had been attracted to the area and 100% of respondents indicated that they would consider returning to the area in the future. However, after being shown 'scaled photo-montages' of the proposed wind farm (panoramic photographs of the array from various locations produced according to offshore wind industry summary guidance), 80% of respondents stated that the development would affect their decision to return (14% said it would not affect their decision, 6% stated "don't know"). Given that the estimated total spend of the respondents in the local area was £34,360 (n=79; mean total spend £435), it was calculated that losing 80% of return visitors would result in a loss of £27,488 to the local economy.
In contrast, some studies have suggested that offshore wind farms could bring economic benefits to the local tourism industry. A report by BWEA (2006) reviewed numerous studies and surveys assessing the impacts of wind farms on tourism in the UK, including two operational OWFs in England and Wales. The report stated that E. ONUK's Scroby Sands Information Centre welcomed 30,000 people in the first six months (from May 2004), and in 2009, 42,000 people visited (Jenny Hogan, Scottish Renewables, pers. comm. 3 Feb 2011). The report also refers to a public attitude survey towards the operational North Hoyle OWF in North Wales undertaken in 2004. Two thirds (67%) of the residents in the Rhyl and Prestatyn areas said that the presence of the North Hoyle OWF had not affected the number of people visiting or using the area; 11% of residents said numbers had increased while 4% said numbers had decreased; the remaining 82% did not see any effect on visitor numbers 43.
Commercial wildlife boat trips such as whale watching trips have the potential to be impacted directly by the physical presence of the wind farms by making access difficult to routes often used by the boats or by interrupting lines of sight while scanning for wildlife with scopes or binoculars. In addition, changes to the abundance or distribution of target species in an area arising from potential environmental impacts (see section 4.13) could cause 'knock-on' effects to the marine wildlife tourism sector. Although there is some uncertainty concerning actual environmental impacts, such risks are generally considered to be low. In particular, most of the species of interest to marine ecotourism such as cetaceans, seals and seabirds are protected under the EC Birds and Habitats Directives with a legal obligation to ensure that adverse effects on the integrity of designated sites are protected and wider provisions to avoid or minimise disturbance of protected species. Therefore, any impact to marine ecotourism species would be expected to be very minor. The current assessment has therefore assumed these impacts to be negligible.
Impacts from offshore wind farms specifically on visitors to coastal/links courses are unknown, as are the impacts on future golf course development in such areas.
The assessment of impacts on tourism has focused on potential changes in tourism expenditure based on visual impact but also takes account of the potential to deter tourism investment. If landscape and visual impacts arising from offshore wind farm development have a negative effect on tourism through deterring visitors to a region, the loss of tourism expenditure could lead to a reduction in economic activity and result in a loss of income and/or jobs. The review of available information above indicates that both positive and negative impacts could occur. However, the existing evidence base is underdeveloped, and further research is required to provide an improved understanding of overall impacts.
Proposed development in the East and North East Regions is further offshore (a minimum of 14km from the nearest land) and in areas where existing seascapes are less sensitive (Scott et al, 2005). The impacts on general tourism in these regions are therefore considered to be negligible under all scenarios. The economic impact assessment has therefore focused on potential changes in West and South West Regions. The basis for the scenarios is given in Table 32.
Table 32. Assumptions for scenarios for tourism
High Impact Scenario
Negative impacts arising from short term option development results in a 1.72% reduction in tourism expenditure in both the West and the South West Regions (based on the worst case scenario in the Dumfries and Galloway regional case study in the Riddington et al, 2008 study). It has also been assumed that there are no positive impacts on tourism and hence this effect is not negated to any degree. Loss of investment in a resort development in West Region leading to a loss of annual revue of £3m p.a.
Medium Impact Scenario
Negative impacts arising from short term option development result in a 1.30% reduction in tourism expenditure in both the West and the South West regions (based on the best case scenario in the Stirling, Perth and Kinross regional case study in the Riddington et al, 2008 study). This figure was chosen to represent a scenario in which there was a reduction in tourism spend arising from seascape visual impacts of the short term options (e.g. about 1.5% based on the Caithness and Sutherland and Scottish Borders regional case studies in the Riddington et al, 2008 study) but that positive impacts arising from new tourism opportunities related to the short term option development offset this to a certain degree.
Low Impact Scenario
While there is the potential for an indirect negative effect on tourism visitor numbers and hence tourism expenditure, positive effects arising from the creation of new tourism opportunities, such as offshore wind farm-related information centres and boat trips to the offshore wind farms, may negate these impacts
The value of tourism in the South West Region has been based on the total tourism expenditure from domestic and overseas visitors in the Dumfries and Galloway area; £143m in 2009 (see Table 18). Likewise, the value of tourism in the West Region has been based on the total tourism expenditure in the Argyll, Loch Lomond, Stirling and Forth Valley Region: £408m in 2009 (see Table 20). Tourism expenditure has been assumed to be constant over time. It is important to note that these values represent all tourism within the VisitScotland regions and not just coastal tourism and are therefore likely to be over-estimated. In addition, the VisitScotland regions did not necessarily align with the OWE Plan regions and this is particularly true for the West Region.
In the high and medium impact scenarios, the loss of tourism expenditure within each region was calculated as follows:
- The total tourism spend (£million) within the most relevant VisitScotland regions were identified for the OWE Plan West and South West Regions;
- The area within each OWE Plan Region which may be affected negatively by short term development options as a result of seascape impacts was estimated based on the likely spatial extent of the main visual impact along a coastline. These values, which were derived by estimating the proportion of the region for which the arrays would be visible, were estimated as 6% for the West Region and 15% for the South West Region with reference to the form and topography of the local coastline;
- From these two sets of values the proportional regional value of tourism expenditure within the zone of influence of the short term option developments was calculated;
- The estimated loss of general tourism-related expenditure per region was then calculated as : Estimated tourism expenditure within the zone of influence of offshore wind farms x 0.0172 (high impact scenario) or x 0.013 (medium impact scenario).
The lack of resolution of the data and difficulties in estimating the zone of influence of offshore wind farms mean that the estimated cost impacts are relatively uncertain.
The assessment for the medium and high impact scenarios has assumed that the expenditure is lost from the relevant region and from Scotland as a whole. The Riddington et al (2008) study on which the assessment is based, has estimated reductions in expenditure for its case study areas, which are broadly of a similar scale to draft Plan regions. Thus the assumption that displacement occurs from within a Region is possibly valid. However, the assumption that displacement occurs for Scotland as a whole is likely to be conservative, as some expenditure is likely to be displaced to other Regions within Scotland.
In addition to estimates of general tourism related impacts, the high impact scenario also assumed that short term option development in West Region would lead to a loss of investment in one resort development, leading to a loss of annual revenue of £3m. This is based on information provided by SDI and Argyll and Bute Council relating to a specific development proposal in West Region which would be of regional significance (Kenneth Clark and Robert Pollock pers. comm. Jan-Feb 2011).
4.11.3 Estimation of Costs and Benefits
Estimates of costs associated with the different scenarios are presented in Table 33 below. The highest costs are estimated to occur in West Region particularly associated with the potential loss of a major resort development.
Table 33. Estimated reductions in expenditure on tourism
4.12 Social Impacts
4.12.1 Description of Costs and Benefits
Social impacts tend to occur as an indirect consequence of impacts to environmental and economic factors such as water quality, noise, seascapes and landscapes, and jobs. However, the scale of impact is difficult to assess given the lack of information on social values. Monitoring information from existing wind farms does not take such aspects into account meaning that there is a lack of information on the precise nature of impacts and levels of significance. Finally, existing wind farms are very different in scale and location (mostly onshore) to many of the projects proposed in the Draft plan, particularly in relation to remote and fragile communities, complex coastal seascapes and unique social structures, and may not provide appropriate examples to support the evidence base.
In addition, this assessment considers the potential for beneficial impacts from developer contributions such as jobs, manufacturing, assembly, construction, operations and maintenance and infrastructure improvements (road networks, ports and air travel).
The regional assessments below provide information on specific impacts that have been highlighted within the consultation responses on the SEA (Marine Scotland, 2010c) and wider social impacts and benefits that may accrue as a result of implementation of the scenarios. No attempt has been made to value social impacts and benefits in this study.
184.108.40.206 North East and East Regions
No specific social impacts were identified in consultation responses to the SEA Environmental Report, although a number of other impacts will have potential social consequences. Beneficial consequences are likely to accrue as a result of job creation, skills training and long-term employment. Development of the supply chain may also support regeneration and help to tackle deprivation. Negative social impacts may arise as a result of economic impacts, particularly for example in relation to commercial fishing, which may affect local fishing communities. Within the North East and East Regions the scale of social impacts is expected to be relatively minor whereas the scale of potential benefits could be large, particularly if higher retention rates are achieved, thus boosting investment and jobs. The size of all social impacts, both positive and negative, is likely to be related to the scale of implementation.
220.127.116.11 South West Region
Impacts on communities were a strong theme within the public consultation workshops in the region, with concerns about negative impacts not being compensated with any local economic benefits. People were also very concerned about impacts on the wellbeing of local communities, including from noise, loss of tourism jobs and income, and energy costs. Potential impacts on people's health were raised as well as more specific impacts including noise and shadow flicker.
There were many views that the scale of development overall would undermine some of the essential qualities of the Solway coast, including its wild and isolated character. Landscape, seascape and visual impacts were the most significant concerns, forming a key theme within the local consultation workshops and an issue shared by the vast majority of individual respondents. There was concern that impacts on the scenic quality of the area could reduce the attractiveness of the region as a retirement location and undermine fragile housing markets. Impacts on property, business value and house prices were general concerns
Negative social impacts may also arise as a result of economic impacts, particularly for example in relation to impacts on tourism or commercial fishing, which may affect local communities. Such social costs are likely to be related to the scale of implementation.
Beneficial consequences are likely to accrue at a regional level as a result of job creation, skills training and long-term employment, particularly if high retention rates can be achieved. Development of the supply chain may also support regeneration and help to tackle deprivation. It remains unclear how many of these benefits may accrue locally.
18.104.22.168 West Region
As with the South West Region the majority of concerns identified by stakeholders related to visual, landscape and seascape impacts and the indirect consequences for the community in terms of quality of life. A range of other concerns were also identified including:
- Impacts on the value and sale of properties and businesses;
- Availability and affordability of housing;
- Health impacts as a result of construction noise and disturbance, shadow flicker and vibration;
- Capacity of local health services, education services, transport infrastructure, water and sewerage infrastructure;
- Radio and TV reception;
- Fragility of local communities in being able to adapt to change;
- Changes to traditional ways of life (e.g. crofting and fishing); and
- Demographic change and its potential for secondary effects on services, the community and the environment.
Negative social impacts may arise as a result of economic impacts, particularly for example in relation to impacts on tourism or commercial fishing, which may affect local communities.
Beneficial consequences are likely to accrue at a regional level as a result of job creation, skills training and long-term employment, particularly if high retention rates can be achieved. Development of the supply chain may also support regeneration and help to tackle deprivation. It remains unclear how many of these benefits may accrue locally.
It has been noted that further baseline surveys might be required to better reflect the characteristics of west coast communities that could be affected by proposals within the Plan. Argyll Renewables Communities (2010) made a number of recommendations concerning the requirements for future research to better inform the assessment of social impacts and to avoid unacceptable impacts.
4.13 Environmental Impacts
The draft SEA Environmental Report (Marine Scotland, 2010a) provides information on the potentially significant environmental effects of the short term options. The report summarises the potentially significant effects in the absence of mitigation measures and also identifies the potential residual effects following application of strategic and specific project-level mitigation measures.
It is beyond the scope of this Impact Assessment to seek to place monetary values on the potential environmental effects. However, where the potential environmental changes could affect other marine users or interests, the study has sought to value these potential impacts. For example, the study does not seek to calculate a monetary value for changes in landscape or seascape but does provide an evaluation of the potential economic impact of those changes on relevant activities such as tourism.
Table 34 (adapted from Table 8.4 of the SEA Environmental Report) summarises the predicted residual environmental effects for each region for the main receptor categories.
Table 34. Summary of potential residual environmental effects of short term options
(Adapted from Marine Scotland, 2010a)
The findings of the SEA Environmental Report relate to full implementation of the Plan. Reduced development could significantly reduce visual impacts and reduce risks to other receptors. However, the climate change benefits would be correspondingly reduced.
4.14 Summary of Impacts to Other Marine Users and Interests
A summary of other marine users and interests that are considered likely to incur costs as a result of short-term option development is presented in Table 35. Specific costs may accrue to the commercial fishing, shipping, recreational boating, recreational angling and tourism sectors.
For the shipping and ports sector and the aviation sector it may also be necessary to implement additional mitigation measures. However, it is considered unlikely that these costs would fall to these sectors. For the purposes of this study it has been assumed that these costs are included within the overall construction costs of the short-term options.
Table 35. Summary of affected sectors and impacts
Main Economic Impact
Loss of revenues from displacement of fishing activity
Shipping and Ports
Increased costs from additional steaming distances
Wave and Tidal Energy Development
Cables and Pipelines
Increased costs from additional steaming distances
Loss of expenditure on related activities from displacement or cessation of activity
Surfing, Windsurfing and Kayaking
Loss of expenditure from displacement or cessation of activity
Not quantified. Negative impacts as a result of impacts to existing economic activities; positive impacts as a result of offshore wind farm supply chain development
Table 36 presents a summary of estimated annual costs (undiscounted) for those sectors that are considered likely to incur costs as a result of short-term option development. The total annual costs range from £0.34m in the low impact scenario to £8.28m in the high impact scenario. The highest estimated costs are associated with commercial fisheries, shipping and ports, recreational angling and tourism sectors which are all broadly of a similar magnitude. Approximately 60% of the high impact scenario costs are estimated to occur in West Region, primarily related to potential cost impacts on tourism.
Table 36. Summary of estimated costs to other marine users (£m per annum undiscounted)
Commercial Fisheries 1
Shipping and Ports
Total Quantified Costs
1 NB: low costs only apply for 5 years following construction; high costs apply for full plan period.