Publication - Progress report

Draft Sectoral Marine Plans for Offshore Renewable Energy in Scottish Waters: Socio - Economic Assesment

Published: 25 Jul 2013
Part of:
Marine and fisheries
ISBN:
9781782567509

The study reported here provides a high level socio-economic appraisal of the potential costs and benefits to activities that may arise as a result of offshore wind, wave or tidal development within the Draft Plan Options as part of possible future Scotti

383 page PDF

4.7 MB

383 page PDF

4.7 MB

Contents
Draft Sectoral Marine Plans for Offshore Renewable Energy in Scottish Waters: Socio - Economic Assesment
B5. Commercial Shipping

383 page PDF

4.7 MB

B5. Commercial Shipping

B5.1 Overview

Commercial Shipping provides for the transport of freight and passengers both within Scottish waters and internationally. Shipping routes can be split into two distinct types; transiting vessels passing through Scottish Waters and vessels with either their origin or destination port within Scotland. The movement of vessels is monitored and recorded by the Maritime and Coastguard Agency ( MCA) and individual port authorities. Port information is described in Section B9 of this Appendix and there is an intrinsic link between shipping and ports, however the interactions and issues in relation to marine renewable developments are often distinctly different. Information sources used in the assessment are listed in Table B5.1.

Table B5.1 Information Sources

Scale

Information Available

Date

Source

Scotland

Baseline review of data on commercial shipping.

2012

ABPmer (2012)

Scotland

Passenger and vehicle ferry routes in Scotland, from the Scottish Government's Urban/Rural Classification for 2009-2010. Plus, Orkney Ferries and Calmac Ferries routing information added in 2011.

2011

Spatial Data Management Team, Rural Payments Inspections Directorate ( RPID), Scottish Government

UK

AIS density grid for one month (January 2008) provided by the Maritime and Coastguard Agency ( MCA). The date includes all vessels transmitting during the month period, and represents vessel of 300 Gross Tonnes ( GT) and all passenger ships regardless of size passenger. Other vessels will also be included in the dataset such as fishing, leisure, military, police and port craft, where these craft are transmitting AIS information. Each grid is representative of approximately a 5km 2 area. The density grid does not allow distinction by vessel type, not does it provide routing information.

2008 - January

MCA AIS data

UK

Admiralty charted formal anchorages.

2013

UK Admiralty charts

European

Combination bathymetry file of

European Marine Observation and Data Network ( EMODNET) bathymetry merged with SeaZone data captured in coastal wave models, and General Bathymetric Chart of the Ocean ( GEBCO) data which was used to cover areas lying outside the extent of the SeaZone and EMODNET data coverage.

2010

ABPmer, 2010. (R.1684 'Seabed Kinetic Energy - EUseaMAP')

The movement of vessels is monitored by the MCA's network of Automatic Identification System ( AIS) receivers and presents the most robust national dataset for defining the spatio-temporal activity of the Shipping sector. AIS transmission is mandatory for all vessels greater than 300 gross tonnes ( GT) and for all passenger ships regardless of size. This assessment uses an AIS density grid at 5 km2 mesh size for Scottish waters provided by the MCA ( Figure B5). The AIS Density Grid identified cumulative vessel (transit) movements for January 2008.

Whilst the above marine traffic is not considered in this chapter, it should be noted that Section B4 provides an assessment of Fishing and uses Vessel Monitoring System ( VMS) data to spatially define activity levels. In addition, recreational boating has been addressed in Section B11 and identifies indicative recreational boating routes.

Whilst this assessment uses a representative set of data to evaluate the socio-economic consequences from individual Draft Plan Option areas, it should be noted that any marine renewable site development would be subject to individual assessment which includes evaluation of shipping and navigational risk. The majority of development site navigational risk assessments would also be underpinned by a marine traffic survey relevant to the baseline marine traffic use. The assessment presented in this section provides a high level socio-economic appraisal based on a number of nationally applicable assumptions.

B5.2 Future Trends

Shipping volumes bear a direct relationship to the global economic market. As markets react to the changing financial situation, shipping lines respond with services to move goods and people. The most notable variable to affect the volume and intensity of shipping into the future will be the technology and innovations used to design future shipping. Ship design seeks for bigger, faster and more economic transhipment of goods and people.

The introduction of bigger ships places expectations that existing ports will increase the depth of water in entrance channels and alongside berths to accommodate changing ship requirements. This implies that investment is necessary in port infrastructure, both in terms of shore side facilities and access to the ports. Channel widths may need to increase to take account of the wider ship beam, which in addition may lead to the requirement for turning circles to be enlarged to take account of greater vessel length. Although all of these pressures have to be taken into account, probably the most significant factor to challenge traditional ports in the context of their ability to accommodate bigger ships is sea access, and in particular vessel draught. New future shipping routes may also lead to shipping increases, especially in respect to the potential for a viable North West passage

In respect of lifeline ferry services, which make up significant proportion of vessel movements within Scottish waters, the Scottish Government have prepared a long-term ferries strategy (2013-2022). The Draft Ferries Plan was published in December 2011 and the consultation period ran until March 2012, with the final Ferries Plan published in December 2012. The plan makes recommendations regarding where investment should be focused to improve connections for island and remote rural communities, improve reliability and journey times, maximising opportunities for employment, business, leisure and tourism and promoting social inclusion (Transport Scotland, 2012).

Planned and possible future offshore renewables development over the assessment period could interact with commercial shipping activity. Such development is likely to preclude passage of commercial vessels through areas occupied by arrays with the potential to increase steaming distances and times on some routes. However, the overall impacts on shipping activity are considered to be relatively minor.

B5.3 Potential for Interaction

Table B5.2 shows potential interaction pathways between commercial shipping and wind, wave and/or tidal arrays.

Explanation of column content:

Column 1: Describes the potential interaction between the activity and any renewable technology;

Column 2: Identifies the types of offshore renewable development (wind, wave or tidal) for which the interaction may arise;

Column 3: Identifies the potential socio-economic consequence associated with the interaction identified in Column 1;

Column 4: Indicates whether detailed assessment will or will not be required if activity is scoped in;

Column 5: Identifies how the socio-economic impact will be assessed.

Table B5.2 Potential for Interaction

1

2

3

4

5

Potential Interaction

Technology Relevance (Wind, Wave, Tidal)

Potential Socio-economic Consequence

Requires Detailed Assessment ( ) or Does Not Require Detailed Assessment (X)

How the Economic Impact Will be Assessed

Obstruction of transiting vessel/ferry routes; increased steaming distances/time

All arrays

Increased costs, effect on regular route (ferry) competitiveness, potential for increased insurance costs; and

Critical lifeline services become uneconomic leading to service termination.

Assess potential additional steaming distances/times

Reduced ferry turnaround times due to increased steaming times for vessel routes

All arrays

Increased costs

Site-specific consideration with operators

Displacement of anchorage areas

All arrays, export cables

Increased costs

(arrays)

Assess potential additional steaming time/costs for alternative anchorages

B5.4 Scoping Methodology

B5.4.1 Impacts to Shipping Routes and Ferry Routes

The presence of wind, wave and tidal arrays and the construction of their associated export cables may cause obstruction and displacement of shipping routes, leading to increased steaming time and therefore increased cost. This will occur where commercial shipping routes and Draft Plan Option areas and/or cable corridors spatially overlap. Cable corridors affect shipping during the process of laying cables with temporary increases in collision risk and/or a requirement to avoid areas of work to reduce the risk of marine incidents.

As a base assumption, where density of development is less than 5% of the Draft Plan Option area, then it is assessed that avoidance of significant impacts can be achieved through spatial planning. As such, the following scoping methodology was applied for proposed wind, wave and tidal Draft Plan Option areas plus their associated cable corridors.

Offshore Wind:

  • Where Draft Plan Option areas are transected by commercial navigation route(s) or ferry routes, the density of traffic has been assessed. If the density of traffic is 5 or more vessel movements per day, the area has been scoped in;
  • If the Draft Plan Option area is transacted by an IMO recognised "ship routeing system", the area has been scoped in; and
  • If the spatial extent of indicative arrays for a given scenario occupy less than 5% of Draft Plan Option area it has been assumed that spatial planning of the Draft Plan Option area can be used to avoid significant impacts under this scenario and the area has been scoped out.

Wave:

  • Where Draft Plan Option areas are transected by commercial navigation route(s) or ferry routes, the density of traffic has been assessed. If the density of traffic is 5 or more vessel movements per day, the area has been scoped in;
  • If the Draft Plan Option area is transacted by an IMO recognised "ship routeing system", the area has been scoped in; and
  • Where the spatial extent of indicative arrays for a given scenario occupy less than 5% of Draft Plan Option area it has been assumed that spatial planning of the Draft Plan Option area can be used to avoid significant impacts under these scenarios and the area has been scoped out.

Tidal:

  • Where Draft Plan Option areas are transected by commercial navigation route(s) or ferry routes, the density of traffic has been assessed. If the density of traffic is 5 or more vessel movements per day, the area has been scoped in;
  • If the Draft Plan Option area is transacted by an IMO recognised "ship routeing system", the area has been scoped in;
  • Where Draft Plan Option areas are in waters of depths greater than 75m, the area has been scoped out. This follows the rationale that tidal devices are stationed circa 20m from the bed (to avoid bed turbulence) and have a maximum blade around 10m in diameter, providing a 30m bed-to-blade-tip clearance. Ultra Large Crude Carriers have a maximum draught of around 35m. An Under Keel Clearance allowance of 10m is applied as a maximum working clearance ( NOREL NAV Sub Group, 2012); and
  • Where the spatial extent of indicative arrays for a given scenario occupy less than 5% of Draft Plan Option area it has been assumed that spatial planning of the Draft Plan Option area can be used to avoid significant impacts under this scenario and the area has been scoped out.

B5.4.2 Displacement of Formal and Informal Anchorages

Offshore Wind:

  • Where an anchorage is within a Draft Plan Option area, it is scoped in;
  • Where a cable corridor crosses an anchorage, it is scoped in; and
  • Where the spatial extent of indicative arrays for a given scenario occupy less than 5% of Draft Plan Option area it has been assumed that spatial planning of the Draft Plan Option area can be used to avoid significant impacts under this scenario and the area has been scoped out.

Wave:

  • Where an anchorage is within a Draft Plan Option area, it is scoped in;
  • Where a cable corridor crosses an anchorage, it is scoped in; and
  • Where the spatial extent of indicative arrays for a given scenario occupy greater than 5% of Draft Plan Option area it has been assumed that spatial planning of the Draft Plan Option area can be used to avoid significant impacts under these scenarios and the area has been scoped out.

Tidal:

  • Where an anchorage is within a Draft Plan Option area, it is scoped in;
  • Where a cable corridor crosses an anchorage, it is scoped in; and
  • Where the spatial extent of indicative arrays for a given scenario occupy less than 5% of Draft Plan Option area it has been assumed that spatial planning of the Draft Plan Option area can be used to avoid significant impacts under this scenario and the area has been scoped out.

The detailed output of this scoping exercise is presented in Appendix C5.

B5.4.3 Data Limitations

The processed AIS data available as a density grid at the time of completing this assessment has inherent limitations. The available AIS data density grid was produced from one month's AIS data (January 2008). This presents a limitation regarding seasonal traffic variability, especially in routes which reflect tourism (ferry routes) or seasonal transport of goods. However, it is considered that a threshold of 5 transits within one day used as a scoping threshold will have captured broad-scale sea area usage. This assessment can be improved through the use of more recent AIS data. To remove seasonality trends, AIS data should be representative of the whole year.

AIS transmission is only mandatory for all commercial vessels above 300 GT and all passenger ships regardless of size. As a result, the following vessel classifications are not accounted for in the AIS data and as such are not considered within this section:

A) Commercial vessels below 300 GT;

B) Recreational vessels;

C) Fishing vessels; and

D) Naval vessels whilst on deployment.

B5.5 Assessment Methodology

The assessment methodology presented in this section takes account of stakeholder concerns regarding the interaction of renewal energy (wind, wave and tidal) on the Commercial Shipping sector.

B5.5.1 Impacts to Shipping and Ferry Routes

Vessel routes, identified from AIS intensity maps have been used to evaluate the potential annual volume of traffic (to the scale of the AIS map output) which would have to be deviated around the development scenarios within the Draft Plan Option areas. The development scenarios are based on the low, central and high estimates of the proportion of the Draft Plan Option areas to be developed, which varies for each technology. To carry out an assessment of the effects of each Draft Plan Option area development on shipping and ferry routes, an average density of shipping has been calculated using the AIS mapping for each Draft Plan Option area (this average area includes all vessels within the AIS data-set include ferry traffic). The low/central/high scenario percentage areas of occupancy have been converted into an area of coverage within each Draft Plan Option area. Each percentage of occupancy has then been represented as a square with a 1km buffer round it.

The deviation has been calculated by assuming that vessels will commence their direction change 10km either side of the square identified as the array occupancy. From this methodology, an assessment of deviation in nautical miles has been calculated to arrive at additional steaming distance.

For both the ferry and commercial shipping routes, the difference in distance between the original and modified routes determine the fuel cost, based on an assumed fuel consumption rate of 2,941 litres per hour at a speed of 20 knots. This is based on an average assumed vessel fuel consumption (measured in MT (metric tonnes)) per day of 60 MT, at 2.5 MT per hour, for a large cargo vessel travelling at 20 knots, where 1 MT (1,000 kilograms) equates to 1176.5 litres based on an average diesel fuel density of 0.820 kg/l. The density of diesel varies according to its grade, within this assessment, an average diesel fuel at 15ºC with a density of 0.820 kg/l has been assumed.

For this costing assessment low sulphur fuel has been used, this is the most expensive option but one that will be compulsory from 2015 in Sulphur Emissions Control Areas, the assessment has used a cost of circa $1000 per tonne. Therefore, the unit pence per litre (ppl) used in this assessment was taken to be 56.29 ppl. In addition the use of this fuel for propulsion carries with it an additional duty of 11.14 ppl based on HMRC rates from 2012.

The above vessel fuel rationale has been applied within this assessment however, it must be noted that, a range of variables affect the fuel burned per hour. These include ship type and size, the precise fuel type and grade being used, different engine types, the age and service history of engines, met-ocean effects, the vessel hull hydrodynamic and the wider economic pressures which dictating vessel speed. For example, slow steaming is currently a technique used by Commercial Shipping operators to minimise fuel, as significant cost savings results from sailing at 12 knots instead of 24 knots. This has become a commonly deployed measure for addressing shipping costs in response to recent economic pressures and fluctuating fuel costs.

Using the additional steaming distance and fuel price, the costs associated with the deviation and additional steaming distance was calculated where the additional cost of steaming time was calculated as:

Current route (distance in nautical miles) compared to additional steaming distance (nautical miles) x fuel costs per nautical mile. The calculation uses an assumed average vessel speed to arrive at fuel consumption per vessel movement. To then infer the annual cost, the journey fuel consumption was multiplied by the average vessel transit count within the Draft Plan Option area in one year. The calculated cost uses 2012 as the baseline year, from which a 2% increase has been applied for future cost projections.

The results of this assessment are presented in Section C5.2 where the described methodology was applied.

B5.5.2 Increase in Marine Risk

Radar interference from offshore wind installations is a known factor with respect to marine safety. This increase in marine risk has been assessed qualitatively with comments regarding possible mitigation measures. Mitigation cost would be transferred to the developer and hence no quantitative assessment of this cost was undertaken. However, relevant stakeholders were consulted to ascertain whether there were any issues or concerns about any of the Draft Plan Option areas, and the scale of any potential issues.

There is also a temporary increase in marine risk along cable corridors whilst cabling is laid. Developers are responsible for ensuring appropriate Navigational Risk Assessments are provided for their marine works, hence no quantitative assessment of this cost has been undertaken.

B5.5.3 Displacement of Formal and Informal Anchorages

The spatial overlap of Draft Plan Option areas and formal anchorages has been evaluated through comparison of Draft Plan Option areas with formal charted anchorage locations. Where these anchorages are used by specific ports, consultation has been carried out to identify relocation options. The impact has been assessed quantitatively through a calculation of change in steaming distance from the port to the relocated anchorage, plus the associated cost with lifting and laying ship mooring buoys (should these be part of the displaced anchorage). The assessment methodology takes the additional cost of steaming time as:

Current route (distance in nautical miles) compared to additional steaming distance (nautical miles) x fuel costs per nautical mile. The calculation uses an assumed average vessel speed to arrive at fuel consumption.

A qualitative assessment of any other impacts of the use of alternative anchorages has also been carried out (for example; less protected site, greater risk of damage in stormy weather).

Informal anchorages are not available as a data layer from Admiralty Chart producers, and may or may not be marked on charts. Often, an informal anchorage is based on custom and practice with a particular consultee providing evidence of use. Informal anchorages have been evaluated through consultation, and quantified if they are identified through port consultation using the same methodology as formal anchorages.


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