marine spatial planning pilot scenario 1: tidal stream …

MARINE SPATIAL PLANNING

PILOT

SCENARIO 1: TIDAL STREAM ENERGY

(Final)

MSPP Consortium, November 2005MSPP Consortium 11/8/05 v1.0 1

1. INTRODUCTION The purpose of this scenario is to use information within the Irish Sea Regional Plan to identify preferred locations for tidal stream power generation in the plan area which minimise conflict with other current and future use-related activities. 2. POLICY AND TARGETS FOR TIDAL RENEWABLES The goals and objectives for the tidal power generation sector have been identified through consideration of the renewables policies for the UK (as specified within The Energy White Paper - Our Energy Future – Creating a Low Carbon Economy (DTI, February, 2003), policies for the devolved administrations (NPPG6 Renewable Energy Developments (revised 2000) – Scotland; Planning Policy Wales; and Energy: a strategic framework for Northern Ireland 2004) and based on targets for supply of electricity from renewable resources, where these were available. The publication of the Government's Energy Review by the Performance and Innovation Unit (PIU) on 14 February 2002 was a first step towards a White Paper (see below). This aims to set out the future energy policy framework and address the three aspects of sustainable development - economic, environmental and social - as well as ensuring security of supply. Early in 2003, the DTI published the Energy White Paper ‘Our Energy Future – Creating a Low Carbon Economy’. The Energy White Paper sets out the UK Government’s approach to ensuring energy supplies whilst at the same time addressing the pressing issue of climate change and the need to reduce the UK’s use of fossil fuels. The White Paper includes commitments to reduce CO2 emissions by 60% by the year 2050 whilst maintaining the reliability of supply, promoting competitive markets and ensuring domestic supply. The role of renewable energy in the UK energy policy is made clear with a re-iteration of the 10% of supply from these sources by 2010 and an intention to double that level of supply in the following decade. Specific mention is made of large offshore wind farms as a part of the renewable generating infrastructure in ensuring the 2020 ambition is fulfilled, though other renewable energy technologies, including wave and tidal technologies, often referred to as ‘wet renewables’ will also play an important role. These UK level targets are supported by a range of national and regionally derived targets, for example, the North West Sustainable Energy Strategy sets a target of supplying 10% of the region’s electricity from renewable sources by 2010 and achieving a 60% reduction in CO2 emissions by 2050. No specific targets have yet been established for marine renewables in the Irish Sea, although the area has significant potential as a location for offshore wind and tidal stream renewable energy developments. Wave energy resources are, however, not considered suitable for exploitation, based on current technologies. Although the power generated from wind energy, both onshore and offshore, will make a major contribution to meeting renewables targets for the UK, the ‘wet’ renewables sector also has a significant contribution to make. The allocation of space for these technologies will therefore be an important consideration in the achievement of the renewables obligation targets for the UK as a whole.

MSPP Consortium 11/8/05 v1.0 2

For the purposes of the MSP Pilot study, a draft policy for the renewables sector has been developed and is presented below. This policy encompasses offshore wind and ‘wet’ renewables collectively, but for this sector scenario testing process is specifically considered in relation to the development of tidal stream technologies. 3. MSPP POLICY FOR RENEWABLE ENERGY Proposals for renewable energy developments within the plan area will be supported in areas identified as suitable following SEA, subject to:

• Evaluation of the findings from an environmental impact assessment • Complying with the requirements of the Habitats Regulations (for locations within or in

the vicinity of designated or proposed SPAs, SACs or Ramsar sites, or affecting species protected under these Regulations);

• Satisfactory resolution of potential conflicts with shipping, commercial and military radar, fisheries or other site specific interests.

No new offshore wind farm development should be licensed within an established exclusion zone of 8-13km from the coast of [England and Wales]. A consultation zone has been established whereby developers should consult with MOD for all proposals for OWF developments within 10km of identified military exercise areas. Areas for potential tidal stream energy generation will be safeguarded. 4. DEFINITION OF TARGET For the purposes of this study, a target for tidal stream power generation has been estimated, although no such targets exist currently for regional areas within the UK, rather, stated targets for ‘renewable’ sourced power are UK-wide and are non-industry-specific, i.e. no breakdown of energy generation has been identified to be provided solely from offshore wind or any other specific technology. As there are no published targets for the tidal stream industry, a target has been calculated based on the areas of available resource and the projected capacities of devices currently being developed. As it is unlikely, even from an preliminary consideration of the potential tidal resource areas, that all of these areas will be suitable for safeguarding for tidal stream exploitation, a working target of 30% of these areas has been used in this study. Using the renewables atlas (ABPmer, 2004), the areas which offer suitable tidal resource which fit within the limitations detailed in the list of assumptions given below represent a total area of 686km2 of seabed, 30% of which totals approximately 205.8km2. Both areas suitable for piled device technologies and seabed mounted or anchored devices were considered in this calculation, with their respective placement constraints as given below. Using the minimum farm size of 30MW, and the area required for the placement of the farm, again based on the assumptions and constraints detailed below (2km2), this area potentially provides enough space for 103 30MW farms. The energy capacity of these farms would therefore equate to 3090MW (3.09GW). Actual average power output of these farms is taken as being 40% of the badged capacity of the devices, resulting in a target power output from tidal stream technology for the area of approximately 1.24GW. This figure also represents all of the devices working at any given time. A figure of 98% is used to reflect the likelihood of


some of the turbines being unavailable due to mechanical failure or maintenance requirements. Using this figure, the target for tidal stream power capacity from the pilot study area has been estimated as 1.2GW, providing a potential total power output of 10.5TWh/year. 5. ASSUMPTIONS There are a number of constraints for the tidal power sector, not least being the discrete and specific nature of the tidal energy resource. The identification of possible areas for deployment of tidal devices has been based on the following assumptions within the Pilot Study area:

• Tidal flows (spring) of > 2.25 (piled device) or > 2.5m/s (anchored/seabed mounted device)

• Depth range of 20-30m BCD (piled device) or 30-70m (anchored/seabed mounted device)

• Distance from shore <8km (for economic provision of interconnector to National Grid) • Minimum Farm size of 30MW • Minimum area of 2km2 - the estimated area required for 30MW generation

6. TECHNOLOGICAL CONSTRAINTS 6.1 Resource The constraints for the sector are largely reflected in the list of assumptions given above. The economically viable harnessing of tidal power through the use of turbine devices is totally dependent upon the level of resource which exists in an area. The Marine Renewable Energy Atlas (ABPmer, 2004) identifies exploitable wind resources over much of the Irish Sea and has been interrogated to delimit areas which provide tidal streams within the parameters listed in the assumptions above. From this process, exploitable tidal stream resources have been identified to the north of Anglesey and south of Luce Bay, Scotland, with more localised resources off Abbey Head, Scotland and Morecambe Bay. Although considerable resource also exists both south and north of the Isle of Man (IOM), these areas are not included within the pilot study area, so any potential exploitable resource areas within the territorial limits of IOM waters have been disregarded. 6.2 Grid Connection The distance offshore that is economically achievable for tidal energy conversion is assumed to be approximately 8km (John Griffiths, per comm.). This is related to the expenditure incurred as a necessity of connecting the power generating devices to the landward electricity grid network. Additional costs within this aspect of the development of commercial farms relate to the potential cost of construction of an electricity substation on or near to the shoreline. For the purposes of this scenario testing it is assumed that wherever there is a connection point in the general vicinity of the coastline adjacent to a potential tidal resource area, then there will be no constraint with regard to capacity or connection to the existing grid network infrastructure. This will, of course, not always be the case. There is likely to be a degree of competition between offshore power generating stations for access to the grid at the same points (or at location in proximity to one another) as a result of the locations of suitable (exploitable) tidal resource and the potential proximity to other types of generating infrastructure, for example offshore wind


farms. Renewable energy projects that generate electricity normally connect to either the transmission grid or the distribution grid. The difference between these grids is normally the voltage; transmission grid voltages are normally 220 kilovolts and above (132 kilovolts and above for offshore wind and Scotland); distribution voltage levels being normally 11 kilovolts, 33 kilovolts, 66 kilovolts and 132 kilovolts (except offshore wind and Scotland). Although satisfactory for the purposes of this scenario testing exercise, further refinement of information, including the capacity as well as the location of connection points would be required for the actual implementation of a spatial plan. Onshore grid connection issues generally comprise:

• The routeing of cables or overhead lines from the cable landfall on the beach and the existing system either further onshore where a suitable connection point already exists, or at a new connection point created by extending the existing system out towards the landfall; and

• the impact of deeper system reinforcements remote from the connection point that may be required to accommodate the new generation.

It has been assumed that satisfactory resolution of issues relating to landward cable routes can be achieved for any of the possible locations for tidal stream devices. Such issues should generally be resolvable through careful selection of landward routes and/or the adoption of appropriate mitigation measures where required. 6.3 Area Requirements The siting of devices within a given area is location (and resource) specific, the actual area requirements may differ from this assumed requirement, for example the spacing of devices can be as small as 50m apart as long as the devices aren’t positioned within the shadow of adjacent devices. If the layout of the site does result in devices being placed within the tidal shadow of another device, then current thinking is that they may need to be a minimum of 10 diameters apart; i.e. if 15m rotor diameter is used on the unit, the devices would need to be 150m apart. In order to err on the conservative side, this scenario run has been made assuming that turbines would need to be set at this 150m distance, thus each turbine would require 0.07km2 area, a minimum 30 device farm would therefore require approximately a 2km2 area. 6.4 Depth Constraints With regard to depth constraints, it is considered that currently no device will be economic at depths greater than 100m, based on both the cost for construction and necessity for maintenance etc during operational phase. Piled devices are restricted in their depth range due to constraints on piling technology (and potentially the operational maintenance requirements of such devices). Devices which employ anchoring systems or direct placement on the seabed (which are of sufficient mass to maintain position on the seabed without the need for additional anchoring systems) have fewer depth restrictions, though in terms of practicality, a maximum depth of 70m BCD has been used for the purposes of this scenario to reflect realistic and achievable access to devices for periodic maintenance and/ or replacement. From discussion with the industry a maximum depth of 30m has been used for technologies which require the placement of devices on piled supports.


7. CONSTRAINTS IMPOSED BY OTHER USES Interrogation of the atlas data enabled areas to be indicated which fitted the various criteria detailed in the ‘Assumptions’ section above, for both of the two scenarios tested. The areas were indicated as a series of approximately 3km2 cells on the map. Once the areas of economic tidal resource had been identified, the available spatial data, collated during the MSPP project was overlain to investigate the other sectoral areas/constraints which occupy, or had potential issues for, these tidal resource areas. Each sectoral use map was sequentially overlaid on the tidal resource map and areas of intersection were marked. In the first instance, all sectoral uses were considered in order to investigate whether any cells would remain free of constraint following the even-handed application of spatial allocation for existing use, without recourse to prioritisation protocols to arbitrate conflicting demands at a given location. The following section illustrates the approach taken in the establishment of the locations of least constraint for the provision of areas for exploitation of tidal resources within the study area. Figure 1 below shows the areas identified as being both within the physical and logistical constraints of tidal power devices and offering potentially viable tidal resource. The assumptions used in the selection of these areas are given above. It is recognised that alternative criteria may be used for site selection, but the environmental requirements used in this scenario test are considered to be broadly in-line with the requirements of the industry as currently understood. Potentially exploitable areas identified were located off Luce Bay, Scotland (Luce Bay West and Luce Bay East); off Abbey Head, Scotland; off Morecambe Bay, England (Morecambe Bay South and Morecambe Bay West), and off Anglesey, Wales. Although considerable resource lies within Strangford Loch and the Menai Straits, these areas were not selected from the tidal resource atlas (ABPmer, 2004) due to the grid cell size upon which the tidal resource data were calculated. In any case, these locations are afforded a high degree of protection as a result of the designation of the areas for nature conservation, being of international importance and would likely have been identified as areas of prohibitive constraint following the process documented in the sections below. In addition to the omission of these areas, the potentially highly exploitable areas around the coastline of the Isle of Man have also been excluded as the Isle of Man territorial waters are not to be included for consideration within this pilot project. In order to build this base map of exploitable resource areas, two general turbine device types have been considered with differing requirements and constraints; a piled device with a practicable deployment depth range of 20-30m BCD; and a seabed mounted or anchored device with a deployment depth range of 30-70m BCD. Additionally, the areas were selected on the basis of providing a spring tidal flow of 2.25m/s or greater and a spring tidal flow of 2.5m/s or greater for the piled and seabed mounted/anchored devices respectively.


Figure 1 Base Map showing Study Area and Locations of Potential Tidal Resource

Satisfying Selection Criteria Each map of other sectoral use within the study area was then overlaid in turn to highlight the points at which the tidal resource areas and other sectoral use areas were coincident, or indicated an overlap which comprised a conspicuous constraint to deployment of tidal energy devices. The order of the following sections is not intended to infer any priority in the importance or significance of the sectors. The Figure below (Figure 2) shows the location of shipping routes within the study area. When this GIS layer is superimposed upon the resource areas it is evident that there are shipping routes which intersect various tidal resource cells.


Figure 2 Locations of ship routes within study area The northerly limits of the relatively large area of potential resource lying broadly offshore of Anglesey is clearly within an area subject to a high concentration of shipping activity which may thus preclude the prospective renewable energy developments within this area. The southerly zone of the resource area at Luce Bay West is similarly intersected by relatively high shipping activity, as is the area termed ‘Morecambe Bay South’. Although on the figure, the shipping routes are marked as terminating some distance from the port, this is an artefact of the provided data, the shipping routes continuing on towards one or more of the major ports within each area. A close up image of the resource area offshore of Anglesey is presented in Figure 3 below, showing the intersection of routes on the resource cells in more detail. Figure 4 shows the cells intersected by one or more shipping routes once the shipping routes have been removed to illustrate the cells thus potentially ‘sterilised’ by shipping routes across the wider study area.


Figure 3 Close-up view of resource areas offshore Anglesey to indicate detail of

intersection with shipping routes.

Figure 4 Resource cells intersected by shipping routes The successive overlaying of sectoral use maps on the base map of resource cells resulted in an increasing number of these cells being selected as potentially limited in terms of providing opportunity for tidal power exploitation. Figure 5 illustrates the resource cells intersected by high speed craft areas.


Figure 5 Areas designated for High Speed Craft showing intersection with potential tidal

resource cells. The resource cells intersected by shipping routes and high speed craft zones were combined to produce a cumulative constraints map, highlighting resource cells potentially ‘sterilized’ by these two sectoral uses. This initial ‘combined constraint’ map is presented below in Figure 6.

Figure 6 Combined constraints map (Shipping Routes and High Speed Craft Areas)


This process was undertaken for each of the sectoral use maps, each being used to identify areas where existing uses of the sea potentially precluded the allocation of sea areas for the exploitation of tidal power. Taking shipping routes as an example, it is considered that even though shipping lanes and seabed mounted tidal turbine devices do not necessarily inhabit the same zones of a given sea area, that is shipping transits on the sea surface whereas these types of tidal turbine operate from the seabed, there is difficulty in allocating these two sectors for concurrent (multiple) use within a given area. This potentially could be done should the water depth be sufficient to provide an adequate safety margin below the keel of the vessel in transit along the shipping route (or above the tidal device on the seabed). It is not possible to guarantee that no collision between the two could occur, but the risk from damage or accident arising should a device become detached from its mooring system may be unacceptable in an area marked as being ‘safe’ for vessel transit and would require more detailed study. Adding cultural heritage sites to the resource map showed a number of locations intersecting with potential tidal resource cells. The data on location of wreck sites has not, in this instance, been limited to sites with protected wrecks (and exclusion zones), but includes all listed wreck sites. This approach has been adopted at this stage in order to provide the maximum certainty with regard to potential development at a given site. Although from a viewpoint of statutory protection, only sites with protected status would comprise significant barriers to development, the status of general wreck sites is often not well understood, and any preliminary investigations of the wreck which could be required prior to, for example, piling or trenching works, could lead to the identification of unforeseen restrictions on future development. The occurrence of wreck sites (nearshore) is presented in Figure 7.

Figure 7 Locations of wreck sites within the study area


There is a particularly high density of wreck sites in the vicinity of the tidal resource area around Anglesey, including two wrecks with protected status. The inclusion of all wrecks has therefore led to a reduction in ‘available’ cells for development of tidal power generation within this area. The following map (Figure 8) illustrates the cells discounted as a result of the occurrence of wreck sites:

Figure 8 Resource base map overlain by wreck sites to show cells with coincident

wreck sites. The addition of these ‘sterilized’ cells produced the following map, Figure 9:


Figure 9 Combined constraints map (Shipping Routes, High Speed Craft Areas and

Wreck Sites) The process of overlaying constraints continued with the inclusion of the following sectors:

• Submarine Cables • Geological and Nature Conservation • Fishing • Fish Nursery and Spawning Grounds • Mariculture • Marine Recreation (part) • Military Activities • Mineral Extraction (non-energy) • Oil and Gas Exploration/Production • Oil and Gas Interconnectors • Ports and Navigation • Renewable Energy (non-Tidal) • Potential offshore Natura 2000 sites (Annex I habitats)

The inclusion of these constraints enabled the production of a map of cells which were identified as being subject to low constraint and were thus deemed to be preferred areas for potential tidal stream development. When all sectoral interests were overlaid on the tidal resource area map, it was apparent that there were no areas which are currently totally free from other use constraint. This is largely a result of the high level of use characterising the Irish Sea area. The inclusion of sectoral constraints such as ‘areas for general recreational sailing’ and ‘demersal trawling areas’ led to the obvious identification of entire areas of inshore seabed for species such as Plaice and


Herring. These sectoral uses, though of importance for each specific sector, occur over very wide areas (as evidenced by the ‘blanket’ selection of the inshore areas). There is thus no definite limitation to the areas available for these activities to continue, within certain constraints including areas where the fish are present and economic distance to port and so on. The wide area over which such activities occur, therefore, allow a degree of flexibility in determining whether there is scope for zoning of such activities away from specific areas (which represent a minor proportion of the total area available for exploitation by the sectors in question) in order to provide small areas of sea for sectors which are geographically constrained by the occurrence of resource, in this case, tidal stream resource, but is equally applicable to sectors such as marine aggregates and conservation with regard to offshore Natura 2000 sites for example, which are selected/expoloitable only on the basis of the occurrence (and knowledge) of specific resource and/or important habitat. With regard to the marine recreation sector, some aspects were excluded in the initial mapping exercise, specifically General Recreational Sailing areas, Recreational Cruising routes and RYA Racing areas, as, in common with the fishing sector, these areas over which such activities occur are very wide ranging, predominantly within the nearshore zone. With these constraints omitted, the following map of areas of least constraint for development of commercial tidal power device deployment was produced (Figure 9).

Figure 9 Resource cells identified as having ‘least constraint’ for development of tidal

turbine farms. From this map it is evident that considerable scope for development exists even with cells discounted as a result of sectoral interests and constraints, though the main areas are clustered around Anglesey and Luce Bay west, off the Mull of Galloway. In total, these areas comprise some 183.75km2 of seabed, 63.98km2 of which are suitable for the placement of piled turbines in 20-30m water depth, with the remaining 119.77km2 suitable for seabed-mounted or


anchored devices. It is acknowledged that these area estimates do not currently take into consideration the ground conditions at each of these locations which may or may not be suitable for the siting of devices, however detailed site investigation works would be required prior to the commencement of any construction works, and such a level of detail for actual site selection would be beyond the remit of any marine spatial plan. Description of ‘conflicts’ within the tidal resource areas identified. The following tables indicate areas of conflict for each of the sectors where an overlap in terms of sea area occurred for both device-type scenarios.


Resource Area Sector Conflict Luce Bay West Luce Bay East Abbey Head Morecambe Bay South Morecambe Bay West Anglesey Cables Out-of-service coax cable intersection Cultural Heritage Proximity to nearshore

(unprotected) wrecks Intersection (& proximity to further) nearshore wrecks

Intersection (& proximity to further) nearshore wrecks

Intersection with protected wrecks (& exclusion zone) and with unprotected nearshore(& proximity to further) wrecks

Fisheries Mostly within Plaice Intersection with Whiting Proximity to Cod, Haddock, Saithe

Wholly within Plaice Intersection with fishing grounds for: Cod, Haddock, Roker, Skate, Saithe, Sole, Proximity to Herring, ‘pelagic’

Wholly within Herring, ‘pelagic’ , Plaice, Roker, Skate, Sole,

Wholly within Herring, ‘pelagic’, Plaice, Partial intersection with Shellfish Harvesting areas Proximity to Sole

Wholly within Herring, ‘pelagic’ , Plaice Proximity to Roker, Skate, Sole Whiting

Partial intersection with Plaice,

Geol/Nature Conservation Proximity to Scare Rocks SSSI

Proximity to Scare Rocks SSSI Partial intersection with Morecambe Bay SAC

Potential N2K (offshore) Partial conflict with potential Sandbank feature (part)

Mariculture Military Activities Intersection with MOD

Danger Areas, Bombing, Air to air firing,

Intersection with MOD Danger Areas

Intersection with MOD Danger Areas, Firing, demolition firing

Marine Aggregates Oil & Gas Exploration/Production

Oil & Gas Interconnectors/Pipelines

Ports & Navigation Intersection with High Speed Craft Area

Partial intersection withFleetwood Harbour Limits. Major Shipping Routes

Proximity to Major Shipping Route

Non-Tidal Renewables Wholly within DTI OWF exclusion zone

Wholly within DTI OWF exclusion zone

Coincides with Barrow RI OWF site Wholly within DTI OWF exclusion zone

Recreation Wholly within general rec. sailing areas Intersection with Recr. Cruising route(s)

Wholly within general rec. sailing areas Intersection with Recr. Cruising route(s)

Wholly within general rec. sailing areas Intersection with Recr. Cruising route(s)

Wholly within RYA Racing Area, general recr. Sailing areas Intersection with Recr. Cruising route(s)

Wholly within RYA Racing Area, general recr. Sailing areas

Wholly within RYA Racing Area Intersection with Recr. Cruising route(s) and general recreational sailing areas

Dredging & Disposal Proximity to Spoil Disposal Site Partial intersection with Disposal Site. Proximity to maintenance dredge area

Proximity to Disposal Site

Table 1 Identified Constraints for Piled Device Scenario (20-30m depth constraint; >2.25m/s tidal stream


Resource area Sector Conflict Luce Bay West Luce Bay East Morecambe Bay South Anglesey Cables Out-of-service coax cable intersectionCultural Heritage Intersection (& proximity to further) nearshore

wrecks Intersection (& proximity to further) nearshore wrecks

Proximity to nearshore wrecks Intersection with protected wrecks (& exclusion zone) and with unprotected nearshore(& proximity to further) wrecks

Fisheries Intersection with Whiting ground Partial intersection with Saithe, Cod, haddockground Proximity to Plaice Ground

Wholly within Roker, Skate, Plaice, Sole ground Partial Intersection with Herring, Saithe, Cod, Haddock ground

Wholly within Herring ground, Plaice Partial intersection with Plaice ground

Geol/Nature Conservation Proximity to Scare Rocks SSSI Proximity to Scare Rocks SSSI Wholly within Morecambe Bay SAC Potential N2K Sites(Offshore) Partial intersection with potential Annex I

Sandbank Partial intersection with Potential Annex I Reef

Mariculture Military Activities Partial intersection with exercise areas

Submarines/Air/HM Ships Proximity to bombing area

Marine Aggregates Oil & Gas Exploration/Production Oil & Gas Interconnectors/ Pipelines Partial intersection with Pipeline Route Ports & Navigation Intersection with Shipping Route Partial intersection with High Speed Craft

Area Proximity to Shipping Route

Proximity to Shipping Route Intersection with Shipping Route Partial intersection with Traffic Separation Scheme

Non-Tidal Renewables Recreation Wholly within recr. Sailing area

Intersection with Recr. Cruising route(s)

Wholly within recr. Sailing area Intersection with Recr. Cruising route(s)

Wholly within recr. Sailing area, RYA Raing Area Intersection with Recr. Cruising route(s)

Partial intersection with RYA Racing Area Partial intersection with recr. Sailing area Intersection with Recr. Cruising route(s)

Dredging and Disposal Coincides with disposal ground Coincides with disposal ground Coincides with disposal ground Table 2 Identified Constraints for Seabed-Mounted/Anchored Device Scenario (30-70m depth constraint; >2.5m/s tidal stream


The map of resource cells with least constraint was built upon the conflicts identified in the tables above, and following the process described in the earlier sections with the omission of the Fishing sector and Marine Recreation layers as noted previously. These issues are discussed below. When the fishing activity layers are overlaid on the resource map, several specific fisheries show intersection. There is overlap between cod fishing grounds and the tidal resource areas of Luce Bay East and West , the allocation of space for tidal resource exploitation would result in a reduction in total cod ground area of some 10km2, representing less than 0.08% of the total 12,630km2 area available for cod fishing within the Irish Sea. A similar area, approximately 10km2, of Haddock fishing ground is also affected, at the same locations as the Cod ground intersections. Herring grounds occupy much of the inshore zone to the east of the study area, in addition to inshore areas off the southern parts of the coast of Northern Ireland. Intersection of these areas occurs at the Morecambe Bay tidal resource areas, the Abbey Head area and a small portion of the Luce Bay East area. Again the area concerned is very small in comparison with the total area of herring fishing ground, amounting to some 18km2 from a total of 9,821km2 of marked fishing ground (approximately 0.2%). Plaice fishing grounds again intersect with the tidal resource areas, to a greater or lesser extent at all of the identified resource areas, all but part of the Anglesey and Luce Bay West areas being contained within the broad inshore areas identified as ‘plaice grounds’. The percentage again is very small, being marginally in excess of 0.1%. Sole fishing grounds would potentially be reduced by 0.2% should the areas identified for tidal resource exploitation be safeguarded. Areas fished for Skate and Roker would be reduced by a slightly higher proportion, approximately 0.67%, though this would still be considered as representing a minor proportion of the total fisheries resource available for the exploitation of these species. The most significant impact would be on Saithe fishing grounds. These grounds are relatively discrete, being located to the north of the Isle of Man, south of Scotland within the study area. Even in this case, however, the percentage reduction totals only 2.9%. It is recognised that some areas within marked fishing grounds for various species may be more important, or more productive, than others and also that not all fishing fleets have equal access to all fishing grounds, i.e. fishermen based in Fleetwood are unlikely to fish grounds off Luce Bay, Scotland. Discussion with fishermen and fishing organisations would be required, therefore, prior to the allocation of any areas for tidal stream exploitation within fishing areas to ensure any adverse effects on individuals or on specific sites of primary importance to the industry are minimised. However, on the basis of the generally small proportions of wide ranging fishing grounds which are anticipated to be affected in order to safeguard areas for tidal resource exploitation, it is considered likely that there is sufficient scope to allocate these discrete areas for tidal stream power generation, particularly within the context of the importance of the industry in contributing to the UK’s renewables obligations and those under the Kyoto agreement. Resource cells identified as conflicting with marine recreational activities have been included within cells safeguarded for tidal stream development at this stage. It may be possible to allocate some of these cells for multiple use, as the placement of seabed mounted devices would not necessarily preclude the use of the area for recreational sailing, though piled device placement may as some of these devices have parts of their structure standing proud of the sea surface. The same caveat for this sector would be applicable as that used for the fishing sector interests, that is should any of the tidal resource cells which overlap with recreational


use be considered to be sterilizing a prime area for recreation, the proposed area could be modified to take account of recreational sailing needs. In developing preferred locations for tidal stream devices, we have also been mindful of the potential for designation of offshore Natura 2000 sites. The data on these sites was provided by JNCC as a series of potential Annex I habitat polygons which were used in the same way as the other sectoral constraint areas, being overlaid on the resource map in order to establish whether there were any areas of intersection or overlap. Although these areas have no current protected status, a pragmatic view was adopted assuming that these areas, or at least either some or some parts of these areas, would be subject to development constraint due to the presence of habitats of conservation value. The lack of actual designation for such areas currently means that there is a degree of uncertainty as to what the restrictions on potential development or exploitation of seabed environs within these areas may be. Greater clarity for both Plan makers and project developers will result once more information on the status or likelihood of designation of such areas, is made available. The scenario has also taken account of potential areas for inclusion in a possible MPA network (scenario 3) and areas identified for safeguarding for future aggregate extraction (scenario 2). A number of other potential tidal stream resource areas occur within the plan area. These are generally small and located within, or in proximity to, river estuary systems or within lochs and straits. These areas were not evaluated in detail due to the perceived constraints already existing (and following advice from J. Griffiths) including both conservation restrictions and those apparent in terms of construction/maintenance of the devices. 8. CONCLUSIONS The total area identified during the spatial constraint mapping exercise as providing suitable resources subject to lower levels of constraint was found to be approximately 183.75km2. Of this total, just under 64km2 might be available for piled devices, with the remaining 120km2 available for seabed mounted or anchored devices. This figure compares relatively favourably with the target figure estimated for the sector within the study area of 205.8km2. In terms of percentages for the two general device types considered, the piled device area was identified as being approximately 64km2, the target for this device type being estimated initially as approximately 59km2. The situation is less favourable for the deeper water anchored/seabed mounted devices, with 120km2 identified, from a target of 146km2. However, this still represents some 82% of the target achieved. It should also be noted that a conservative approach has been adopted for this scenario, with entire resource cells considered as being ‘sterilized’ by the occurrence within them of perhaps even small features. For example a wreck site, identified as occurring within the 3km2 area of each cell has been deemed to preclude development within that entire area. In reality, the likelihood of such exclusion from such a large area on the basis of the occurrence of a single, perhaps small, wreck is unlikely to be necessary, since even with a 500m exclusion zone around the feature, some 85% of the cell area would still be available for tidal device deployment.


The scenario has demonstrated that it is possible to identify areas of suitable resource where known constraints from other uses are lower. The robustness of the proposed allocations is dependent on the quality of data on the tidal stream resource and on other use constraints. Precise locations for some uses such as fishing and recreational sailing are not well resolved in the plan. It is likely that potential conflicts with these sectors would best be dealt with through consultation to refine provisional allocations made on the basis of plan data. The areas proposed for safeguarding are not intended to limit the rights of tidal stream developers to explore other possible locations within the plan area, although it might be assumed that these other locations may be subject to greater constraints from existing activities or provide poorer tidal stream resources.


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