Hammars Hill Wind Energy Project
Technical Description and Environmental Studies
Orkney Sustainable Energy Ltd
6 North End Road Stromness Orkney KW16 3AG www.orkneywind.co.uk
Orkney Sustainable Energy Hammars Hill February 2008
Hammars Hill Wind Energy Project
Report OSE/2825
February 2008
Developer: Hammars Hill Energy Ltd
Applicant: Richard Jenkins Savisgarth Evie Orkney KW17 2PQ
Designer: Richard Gauld IEng MInstMC BSc(Hons) Dip. Design & Innovation
Orkney Sustainable Energy Ltd 6 North End Road Stromness Orkney KW16 3AG
Telephone 01856 850054 Facsimile 01856 851239 Web www.orkneywind.co.uk
Richard Gauld is a professional design engineer, a Member of the Institute of Measurement and Control, and is registered as an Engineer with the UK Engineering Council.
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Hammars Hill Wind Energy Project Report OSE/2825
Technical Description and Environmental Studies
This report is presented in two volumes; Volume 1 contains the non-technical summary, the project description, landscape and visual studies, an ecology assessment, reports on archaeology, surface deposits and hydrology, transport impacts, and noise and shadow flicker impact assessment. Volume 2 contains the Site Drawings, Maps and Photomontage Images.
Section 1 Non-technical Summary and Project Description
RICHARD GAULD BSC (HONS), IENG MINSTMC
Section 2 Landscape and Visual Studies
RICHARD GAULD BSC (HONS), IENG MINSTMC
Section 3 Ecology Survey
ANDREW UPTON MA CANTAB, MSc
Section 4 Archaeology Survey
DAVID LYNN, BA (HONS), MSC
Section 5 Hydrology and Superficial Deposits
MICK AUSTIN BSC (HONS), CENG FICE FISTRUCTE
Section 6 Noise and Shadow Flicker Assessment
RICHARD GAULD BSC (HONS), IENG MINSTMC
Section 7 Traffic and Transportation
RICHARD GAULD BSC (HONS), IENG MINSTMC
Volume 2: Site Drawings, Maps and Photomontage Images
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Section 1
Non-Technical Summary and Project Description
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SECTION 1 CONTENTS
SUMMARY 6
1 INTRODUCTION 7
2 DEVELOPMENT DESCRIPTION 9
2.1 PROPOSED LOCATION 9
2.2 WIND ASSESSMENT 13
2.3 CARBON FOOTPRINT AND EMISSION AVOIDANCE 13
2.4 LANDOWNER INVOLVEMENT 14
2.5 CONSULTATION AND ALTERNATIVE LOCATIONS 14
2.6 PROJECT DESIGN STATEMENT 16
2.7 DETERMINING WIND TURBINE SIZE 17
2.8 TRANSPORTATION 20
2.9 ROADS AND FOUNDATION CONSTRUCTION PROGRAMME 20
2.10 WIND TURBINE CONSTRUCTION PROGRAMME 22
2.11 OPERATION AND MAINTENANCE 23
2.12 DECOMMISSIONING 23
3 SOCIO-ECONOMIC BENEFITS AND PLANNING ISSUES 24
3.1 ECONOMIC BENEFITS; AN INTRODUCTION 24
3.2 ENERGY OUTPUT 24
3.3 ENVIRONMENTAL BENEFITS 25
CUMULATIVE ENERGY EXPENDITURE 25
ENERGY PAYBACK TIME 25
HARVEST FACTOR 25
3.4 BENEFITS TO ORKNEY AND THE ORKNEY ECONOMY: 26
EMPLOYMENT 26
INVESTMENT OPPORTUNITIES 26
ENERGY SECURITY 26
RATES & TAXES 26
3.5 LOCAL BENEFITS; EVIE & RENDALL 27
3.6 ECONOMIC BENEFITS; A SUMMARY 27
3.7 NATIONAL PLANNING CONTEXT; SPP6 28
3.8 STRUCTURE PLAN CONTEXT 29
3.9 ORKNEY ISLANDS COUNCIL LOCAL PLAN 30
3.10 DRAFT PLANNING GUIDANCE 33
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4 SUMMARY OF ENVIRONMENTAL IMPACTS 34
4.1 VISUAL IMPACT UPON THE LANDSCAPE 35
IMPACT ON LANDSCAPE CHARACTER 35
ZONE OF THEORETICAL VISIBILITY 35
IMPACT ON VISUAL RESOURCE 36
4.2 ECOLOGICAL IMPACT 39
SETTING AND MANAGEMENT OF THE DEVELOPMENT SITE 39
AIMS AND SCALE OF ECOLOGY SURVEY WORK 39
TOTAL FIELDWORK HOURS 40
VEGETATION 40
OTTERS 41
BREEDING BIRDS 42
WINTERING GEESE 43
BIRDS FROM VANTAGE POINT (VP) WATCHES 43
POTENTIAL IMPACTS 46
4.3 POTENTIAL DISTURBANCE TO ARCHAEOLOGY 48
OBSERVATIONS 48
CONCLUSIONS 49
4.4 IMPACT UPON GEOLOGICAL AND HYDROLOGICAL FEATURES 49
4.5 CARBON EMISSIONS DURING CONSTRUCTION 51
4.6 POLLUTION RISK DURING CONSTRUCTION AND MAINTENANCE 52
4.7 POTENTIAL DISTURBANCE FROM NOISE 52
4.8 POTENTIAL DISTURBANCE FROM SHADOW FLICKER 54
4.9 POTENTIAL RADIOCOMMUNICATIONS INTERFERENCE 56
5 ENVIRONMENTAL MANAGEMENT AND MITIGATION 57
5.1 VISUAL IMPACT MITIGATION 57
5.2 ECOLOGICAL IMPACT ASSESSMENT AND MITIGATION 58
5.3 MITIGATION OF POTENTIAL IMPACT UPON ARCHAEOLOGY 62
5.4 GROUNDWATER MANAGEMENT AND POLLUTION AVOIDANCE 62
5.5 MITIGATION OF NOISE DISTURBANCE 63
5.6 MITIGATION OF SHADOW FLICKER NUISANCE 64
5.7 CONSTRUCTION AND TRANSPORTATION IMPACT MITIGATION 64
5.8 MITIGATION AGAINST TELEVISION INTERFERENCE 64
6 CONCLUSIONS 65
7 REFERENCES AND BIBLIOGRAPHY 66
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Summary
The Hammars Hill Wind Energy Project is being developed by Hammars Hill Energy Ltd, with co- ordination by the landowner, Mr Richard Jenkins of Savisgarth, Evie, Orkney. Orkney Sustainable Energy Ltd are the project designers.
Five wind turbines are proposed for land at Savisgarth. The preliminary turbine chosen for the development is the Enercon E44, manufactured in Germany, although the turbine model may change, subject to availability. The electricity generated will be traded to meet the requirements of the Renewables Order (Scotland) 2002, with the project connecting into the Orkney system under an innovative RPZ grid management system. The project is a locally-owned renewable energy investment scheme, as promoted by the Scottish Government in Planning Policy SPP6, with the whole community invited to become participants.
The project was initiated by the landowner, with Orkney Sustainable Energy Ltd contracted to complete the project design, consultation and environmental studies. Approaches have been made to Evie and Rendall Community Council and Orkney Islands Council Planning Services, and the project has been designed following guidance provided by Historic Scotland, the Royal Society for the Protection of Birds, Scottish Natural Heritage, the Scottish Environment Protection Agency, the Civil Aviation Authority, National Air Traffic Services and OFCOM.
As a result of the environmental studies, the project evolved to use Enercon E44 turbines, with the windfarm designed to avoid shadow impact upon neighbours and to have low noise impact. The turbine locations changed during the course of the project, and to ensure minimal impact upon habitats and species the machines have been positioned away from any designated areas. Studies have been completed to determine landscape and visual impacts, potential noise impact and detailed information on the archaeology of the surrounding area has been sourced from the Orkney archaeologist and The Royal Commission for Ancient and Historical Monuments. Ecological impact has been fully considered, including a habitat survey, a breeding bird survey, and an assessment of mammals on the site. Analysis of the development includes a hydrology survey, extensive photomontage modelling, detailed drawings of the development, a description of the wind turbines and a description of the construction process, leading to the commissioning, operations and eventual decommissioning.
It is concluded that a locally owned wind energy project is feasible for this part of Orkney, with low impacts upon ecology and the local community. Strong social and economic benefits can be achieved by constructing the project, along with the associated climate change benefits resulting from renewable energy production.
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1 Introduction Orkney is an important area for wind energy development; a number of projects have been established in the islands, primarily as cluster developments on hilltop and moorland locations. The Hammars Hill project follows this pattern of development and has been designed as a simple linear development of medium scale wind turbines which avoids dominating the landscape, while providing diversification required for the commercial viability of the farm, along with strong economic benefits to the local community. The development is a privately funded local windfarm, providing significant financial returns to all members of the Orkney community participating in the project. The project complements the grant-supported community wind turbines proposed for the outer isles of Orkney, and provides a direct income stream for participants, thus ensuring strong economic security.
Orkney Sustainable Energy completed preliminary designs and initial consultation in 2006. Detailed ecological and environmental studies have since been completed, resulting in the detailed design and development of a five wind turbine project. Evie and Rendall Community Council have been consulted throughout the development process.
The Hammars Hill project has been designed around the Enercon E44 900kW wind turbine, and although the actual turbine model may alter nearer the time of construction, this machine represents the maximum scale; the site layout and all modelling has used a 45m turbine tower height and a rotor diameter of 44m. The blade length is 21m, allowing for a 2m diameter hub. A grid connection application has been accepted by Scottish and Southern Energy, and it is intended that the turbine will operate under the innovative Registered Power Zone scheme. There are 11 kV and 33 kV electricity transmission lines in the area, and the turbine is to be connected to the local distribution system via a switchgear building to the north of the hill.
The average wind speed at the turbine location is predicted to be 9.6 metres per second (m/s), similar to that recorded at the nearby Burgar Hill windfarm. Based on manufacturer’s predictions, five 900kW wind turbines located on this site will have a capacity factor of around 45% and will produce around 18,000 MWh of renewable electricity per annum, equivalent to the domestic requirements of 3,500 households. Electricity produced from renewable resources avoids the emission of pollution, and the production of 18,000 MWh of wind electricity is projected to avert the production of around 8800 tonnes of carbon dioxide per annum(Carbon Trust). The Hammars Hill project provides a very good contribution towards the Scottish Government renewable energy production and carbon reduction targets.
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This report is presented in eight sections: Section 1 is a project description of the development, including non technical summaries of the environmental impacts, Section 2 of the report contains the landscape and visual studies, Section 3 is the ecology report, Section 4 is an archaeology survey, Section 5 is a hydrology report encompassing civil engineering and the construction of the site tracks, Section 6 contains the results of noise and shadow flicker assessment, Section 7 describes transport impacts and Volume 2 of the report contains the site plans and drawings, maps, wireframe images and photomontages.
Hammars Hill
Reproduced from Ordnance Survey Data, Crown Copyright Reserved. License No. 0100031673
Figure 1.1 – Site Location
Figure 1.1 Site location and turbine positions
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2 Development Description This part of the report describes the activities involved in delivering and constructing the wind turbines at Hammars Hill. The activities considered include civil engineering, transport of the equipment, installation of the wind turbines, operation and maintenance of the project and eventual decommissioning of the turbines. A proposed construction schedule is included.
2.1 Proposed location
The site for the development is an elevated moorland hill above Savisgarth farm, in the community of Evie in the West Mainland of Orkney. Five wind turbines are proposed for Hammars Hill, with each position chosen to be on hard, stable underlying strata. The wind turbine locations, site plan and dimensions are shown in Figures 2.1 to 2.3. The grid references are as listed below, Table 1, with a note of the base elevation and overall height of each installation above sea level, including maximum wind turbine blade tip height. There will be a requirement for a switchgear house with floorplan dimensions of 6m by 4m, located next to the overhead cables to the north of the site.
There is a 33kV grid system in this part of Orkney, used for providing power to the north isles and to accommodate the production of renewable energy from Burgar Hill. The switchgear house will consist of a building appropriate for the location, and is a simple structure resembling a garage located next to the Old Smithy at Hammeron; a schematic is provided within Volume 2 of the report.
Turbine Easting Northing Position Tower top Maximum elevation elevation elevation
T1 E338555 N1022700 144m 189m 211m
T2 E338370 N1022618 150m 195m 217m
T3 E338190 N1022520 149m 194m 216m
T4 E338010 N1022430 137m 182m 204m
T5 E337837 N1022327 132m 177m 199m
Switchgear E339260 N1023105 37m -- 40m building
Table 2.1 Wind Turbine Locations and Elevations
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Figure 2.1
(A3)
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Figure 2.2 - Layout
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Figure 2.3
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2.2 Wind assessment
Preliminary wind resource has been assessed using NOABL, the national wind speed database, www.bwea.com. The mean annual windspeed at the summit of the site is predicted to be 9.6ms-1 at a height of 45m above ground, similar to that recorded at the nearby Burgar Hill wind farm. Assuming this mean windspeed, five Enercon E44 wind turbines located on this site will have a capacity factor of around 45% and will produce around 18,000 MWh of renewable electricity per annum, equivalent to the domestic requirements of 3,500
households, given an average annual consumption of 5 MWh per annum.(Boardman et al 1997).
2.3 Carbon footprint and emission avoidance
In the north of Scotland electricity is produced from a mixture of coal, gas, hydro and wind generation stations. The fuel mixture of Scottish Hydro Electric has above average gas and renewables content, with only a marginal use of nuclear power. The carbon emission factor takes into account all generation sources, and is close to the UK average, Figure 2.4.
Figure 2.4 – Fuel Mix and carbon emissions by Scottish Hydro – Electric (source: www.electricityinfo.org)
Electricity produced from renewable resources avoids the emission of pollution, and the production of 18,000 MWh of wind electricity is projected to avert the production of around
8800 tonnes of carbon dioxide per annum(Carbon Trust), based on a carbon emission rate of
0.489kg CO2 per kWh of generation (www.electricityinfo.org); five 900kW wind turbines in this part
of Orkney will therefore avoid the production of the following emissions (Boyle 1996):
• CO2 8800 tonnes per annum (equivalent to 2100 tonnes of carbon per annum)
• SO2 270 to 360 tonnes per annum
• NOx 66 to 90 tonnes per annum
CO2 emissions have been identified as the primary cause of climate change, sulphur dioxide and nitrogen oxide emissions are a cause of acid rain.
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2.4 Landowner and community involvement
The Hammars Hill Wind Energy Project has been initiated by the landowner, and will be owned by an Orkney company once completed. The project is a locally-owned renewable energy investment scheme, as promoted by the Scottish Government in Planning Policy SPP6, with the whole community invited to become participants. Preliminary assessments indicated that the site could accommodate a small-scale wind energy development, and the scale of the wind turbines has been determined by ensuring the project does not dominate the landscape. Orkney Sustainable Energy Ltd was retained to provide advice to the developers, and has become responsible for all design, planning, consultation and environmental assessment. The development company is Hammars Hill Energy Ltd, which will be responsible for the infrastructure, civil engineering, construction, operations and ultimately the final decommissioning of the project.
2.5 Consultation and alternative locations
The final layout of the project has evolved throughout the design process, and has followed advice and guidance provided by an extensive list of statutory and local organisations. From an initial proposal of 3 x 2.3MW wind turbines located along the ridge of the hill, the layout and scale of the project has evolved to become five small wind turbines positioned in a simple linear layout, providing a total of 4.5MW of renewable energy equivalent to that used by 3500 homes, while at the same time accommodating environmental and social constraints.
Preliminary consultation on the proposed wind farm has been favourable. Full ornithological and habitat surveys have been undertaken in line with national guidance, along with a landscape and visual assessment and a detailed archaeology survey, resulting in the reduction in project size. Advice and guidance from the following organisations has been used to help determine the scale of the project, along with direct consultation when possible.
• Orkney Islands Council, Development and Protective Services • Orkney Islands Council, Environmental Health • Orkney Islands Archaeological Trust • Evie and Rendall Community Council • Historic Scotland, Edinburgh • RSPB, Orkney Office • SNH, Orkney and Shetland Regional Office • SEPA; Kirkwall and Dingwall Offices • Highlands and Islands Airports, Inverness and Kirkwall • Ministry of Defence, Sutton Coldfield
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• Civil Aviation Authority, London • National Air Traffic Services, London • Radio Communications Agency, London
Wind energy development has been encouraged in Orkney; however there are constraints to be considered. The wind turbines should not be a nuisance to neighbours and should be far enough away from properties to minimise noise and shadow effects. Other constraints to consider are impact upon ecological concerns, mainly birds, and to ensure that any archaeological concerns are identified and impact avoided. The installation of an instrument landing system at Kirkwall airport also has implications on wind turbine locations, to ensure that impacts upon aircraft instrumentation and communications systems are avoided.
OFCOM, the radio communications agency, indicated that the nearest communications systems were the T-Mobile and SSE Wideford Hill to Milldoe links and the Thus link between Keelylang and Milldoe. The Milldoe mast is 1.5km from the wind turbines at the nearest point and the radio links will not be affected by the development.
Information on archaeological sites in the vicinity of the project site was provided by Orkney Archaeological Trust, the Orkney Archive and the Royal Commission of Ancient and Historical Monuments of Scotland. The section on archaeology discusses this consultation and the resultant site survey, with no adverse significant impact predicted.
The full extent of locations considered for development included all the land surrounding Savisgarth, and the final area identified for the project has avoided impact upon nature conservation interests on the Orkney West Mainland Moors SSSI and SPA to the south of the hill, and has avoided impact upon the ecological interests around the Burn of Woodwick to the west. The preferred development area for the turbines is thus the elevated land at Hammars Hill, to the south and west of the A966 Evie to Finstown road. Other constraints to consider were the need to avoid impact upon protected bird species and to ensure that the project has negligible impact upon the Neolithic Heart of Orkney World Heritage Site and the Hoy and West Mainland National Scenic Area.
Having identified an area within the boundaries of Savisgarth that was appropriate for development, the final location of the wind turbines was decided by considering visual and landscape issues, and then maximising distances to neighbours to ensure noise and shadow impacts are avoided; the objectives of PAN45 and SPP6 have been achieved by a large margin.
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2.6 Project design statement
The Hammars Hill Wind Energy Project has been designed by identifying all ecological, social and technical constraints in the area, then completing a range of detailed studies to ensure that the site was generally suitable for a wind energy development. Through an iterative process the turbine sizes and positions was then adjusted to produce an optimum layout; the report frontispiece and Figure 2.5 below are two of the project photomontages, and represent the highest magnitude of visual impact from the roads and communities near to the development.
Figure 2.5 – Hammars Hill wind turbines from A966 Skiddy Junction
The wind turbines are to be positioned at an elevation of 150m, on an elevated moorland hill between Evie and Rendall, to the west and south of the A966. The wind turbine locations consist of areas of hardstanding nominally 25m by 35m, with the turbine foundations located below ground level. A temporary trench will be excavated to accommodate the underground high voltage and telecommunications cabling, routed to the north of the project.
The site cabling is underground, ultimately connecting to the grid at a switchgear building, erected next to the A966 by the Old Smithy at Hammeron, to the north of Hammars Hill. A grid application has been accepted by Scottish and Southern Energy, allowing the turbines to operate within the innovative Regional Power Zone proposed for Orkney.
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To avoid shadow flicker nuisance, planning guidelines recommended that wind energy projects should be positioned to a minimum of 10 rotor diameters from neighbouring
properties, where possible(PAN 45). The Hammars Hill turbines have been positioned to avoid shadow impact by ensuring large neighbour clearances and PAN45 recommendations are achieved by a large margin.
Noise from wind turbines disperses naturally with distance and with atmospheric absorption and reaches acceptable levels at a distance of around 500m for single wind turbines. The Hammars Hill wind turbine noise levels are very low, due to topographical effects and long distances; the turbines produces between 22.6 and 35.9 dB(A) at the nearest neighbours, well within national planning guidelines. Note that the turbines proposed for the development do not have a gearbox and accordingly gear-meshing cannot occur, resulting in a quieter turbine with little in the way of a tonal element. Similarly, measurements of low frequency and infra- sonic noise around modern windfarms have shown that levels of such noise are below accepted thresholds of perception even on the wind farm itself. Local and national noise guidelines have been achieved by Hammars Hill development.
2.7 Determining wind turbine size
A range of alternative wind turbine models has been considered for Hammars Hill, figure 2.6. It is intended that the project should attempt to maximise generation within the identified constraints, with ecological and visual impact, noise impact, transportation and grid capacity all important issues. Although Enercon turbines have not yet been deployed in Orkney, all other models are operational in the county. The Enercon E70 was also considered and has similar dimensions to the Nordex N80.
NM92 2.75MW; Nordex N80 Vestas V52; Enercon E44 46 blade / 70m tower 40m blade / 60m tower 26m blade / 45m tower 22m blade / 45m tower B:T ratio = 0.657 B:T ratio = 0.666 B:T ratio = 0.577 B:T ratio = 0.488
100m
75m
50m
25m
Figure 2.6 – Wind Turbine Dimensions
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Enercon E44 – 900kW Enercon are a long established German manufacturer of wind turbines, and are concentrating on the onshore market. Enercon have recently constructed a windfarm of E70 turbines at Boyndie near Banff, and are looking to establish a presence throughout Scotland, including Orkney. By using advanced technology, they have produced machines which are relatively more efficient for the size of the rotor, with this 900kW turbine having a 22m blade rather than the more typical 25 to 26m. Noise levels are also low due to the gearbox-less design and different blade geometry, and has been set at 100 dB(A) at 8m/s wind speed. This machine is an upwind design, with a 44m diameter rotor, a nacelle height of 45m, variable speed operation up to 30 rpm and is IEC class 1A.
Vestas V52 – 850kW Vestas has a range of machines available rated from 850 kW to 3 MW. The Vestas V52 is rated at 850 kW and is part-manufactured in Scotland. This machine is an upwind design, with a 52m diameter rotor, and variable operational speeds of 14 to 30 rpm. Tower height for the V52 is 44m to 55m. Noise levels are low, and can be set at 100 dB(A) at a windspeed of 8 m/s. These turbines are IEC class 1A and can be recommended for sites where the annual mean windspeed reaches 10 m/s. They also recommended for locations requiring low noise emissions and good power quality; the V52 was chosen for the Burray wind energy project.
Nordex N80 – 2.5MW Nordex are a German/Danish company producing a small range of wind turbines between 1.3 and 2.5MW, primarily for the onshore market. The N80 is a 2.5MW wind turbine, and by allowing the machine to run slightly faster than competing machines they have been able to use a 40m blade rather than the more typical 42m. This machine is an upwind design, with an 80m diameter rotor, a tower height of 60m, variable speed operation of 15 to 20 rpm. Noise levels are slightly higher than other equivalent machines due to the higher rotational speeds. This turbine was used for phase 3 on Burgar Hill, Orkney, with two turbines installed in 2006.
NEG-MiconNM92 – 2.75MW The largest wind turbine operating onshore in the UK is the NEG Micon NM92, a 2.75MW wind turbine. A 46m blade is used and although considered, the scale of this machine was deemed to be too large for this type of prominent location, due to access difficulties and visual impact. This machine is an upwind design, with a 92m diameter rotor and a tower height of 60m. A prototype version of this turbine is in operation at Burgar Hill, with further versions running on Sanday.
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Selection process
Each wind turbine has its own specific application. The Vestas V52 is part-manufactured in Scotland, and is both very robust and quiet. The Enercon E44 turbine is also quiet and robust and has a good installed cost per kW. The Enercon E70 and the Nordex N80 were possibilities, however the larger structures were not appropriate for the landscape in this part of Orkney. Given the design requirements of maximum power production within the existing HV network, while avoiding major road construction, reducing visual impact, and avoiding significant noise and shadow impacts on neighbours, the Enercon E44 was identified as being the most appropriate.
The Enercon E44 provides power similar to that of the V52 along with a 15% reduction in rotor size, and is a good fit and is in proportion with the hilltop landscape. Machine availability may change at the time of construction, and accordingly the planning application has allowed for a standard turbine with a blade radius of 22m and a nacelle height of 45m, giving a maximum overall height of 67m. Figure 2.7 is a version of the Enercon E44 recently installed on a Japanese island subject to typhoon category windspeeds.
Figure 2.7 – Enercon E44 900kW Wind Turbine – 72m version
Note that the Enercon turbines are normally supplied with a green banded base that acts to visually link the turbine tower to the landscape.
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2.8 Transportation
Section 7 of this report contains an assessment of transportation to site, including analysis of any corners, turns and bridges. The turbine components will be delivered by sea from the German factory to Hatston Pier in Kirkwall then delivered by extended trailer along the A965 through Finstown, before turning northwards on the A986 Dounby road. It is intended that the turbine components will follow the A986 through Dounby to Birsay, then follow the coastal road through Evie to Savisgarth. This route was established to allow delivery of the large turbines to Burgar Hill, and avoids a difficult turn in Finstown. The manufacturer is experienced in transportation of their wind turbines, and do not foresee any difficulties in the transportation of the turbine components from Kirkwall to the site.
The turbine access track will be levelled and made 4m wide to accommodate the large delivery vehicles, and the general construction technique will be to remove vegetation then create a 4m wide track by filling with as-dug stone directly onto a hard stone strata.
The delivery of long loads through Finstown, Dounby and Evie has the greatest potential for disruption, with traffic management required. Although there are alternative routes for other vehicles, the most appropriate time to deliver these components through Finstown is during the daytime and midweek, when the roads are at their quietest.
Before any wind turbine components are transported to site, the project owners and designers will consult with Orkney Islands Council Roads Department and the Police to ensure acceptability of the route to site. Existing public road culverts, bridges, verges and street furniture will be surveyed by the project developers in conjunction with the Roads Department. A schedule of loads and a timetable will be prepared and circulated prior to delivery. Road warning signs and lights will be located at all areas of road works and any items such as fence posts and road signs that have been temporarily removed will be re- erected following transportation.
2.9 Roads and foundation construction programme
Section 5 of the report discusses road and foundation construction. Stone for the site tracks and hardstandings will be extracted during construction of the turbine foundations and will also be extracted from existing quarries in Orkney. The foundation construction must be completed a month in advance of turbine delivery and the track layout has been designed to minimise visual impact where possible by following an existing field drain and boundary.
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The total volume of concrete required for the foundations will be around 500m3 for the site, and the stone requirement will be approximately 2500m3 of sub-base and bottoming for the track and hardstanding.
The requirement for the track will vary according to ground conditions, and the lower section of the access track to the hilltop from Neigarth will consist of a shallow layer of concrete cast directly onto stone sub-strata. It is further proposed that stone shall be brought onto the site and that a local quarry will be used to source the stone, however there will likely be opportunities to recover rocky glacial till and a proportion of fractured rock during the levelling and excavation of the foundations. Concrete will be delivered to site as drybatch, to be mixed with water at the foundation hardstanding, with no need for local abstraction.
Draft Method Statement:
1. The existing farm track will be widened and generally levelled as far at Neigarth, from whence a new track will be formed around the recently-built cattle building. 2. It is proposed to widen the existing ditch and level its floor with concrete to avoid the need for excavation and disturbance of other ground. 3. Flow down the existing ditch will be confined to the upslope side with sand-bags and concrete will be placed in sections. 4. Water will be prevented from flowing over the concrete until it has set. 5. A series of settlement ponds will be constructed at the foot of the existing ditch to trap water-borne material and prevent it being carried to the Woodwick Burn. 6. The area of soft clay at the head of the existing ditch shall not be excavated and instead a “floating road” shall be constructed using geotextiles to isolate the imported quarry material from the topsoil. 7. The sub-base of the access track will be constructed of coarse material to allow infiltration through the track itself]. The surface will be regulated with fine quarry material. 8. Surface runoff will generally be led to the downslope side of the track and infiltrated into the adjacent soil by means of a perforated drain surrounded in gravel and enclosed in a geotextile membrane. 9. At appropriate sections of the access track, runoff from the upslope side shall be collected by means of a French drain. This will be connected at suitable intervals to the infiltration drain on the downslope side. 10. Drainage shall be provided beneath the track whenever it crosses a flush zone, drain or gully to avoid disruption of natural drainage. Inlets and outlets shall be designed to avoid erosion.
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11. Water shall generally be intercepted and dispersed near to the locations it would have reached before the works were constructed. 12. Collection of large water volumes shall be avoided and infiltration drain lengths kept to a minimum to avoid significant disruption of natural drainage patterns. 13. Alkaline leaching from the turbine bases will be minimised by using a concrete mix designed to resist sulphate attack. 14. Before any excavation the natural surface layer of peat or topsoil shall be carefully lifted and laid aside for reuse. 15. Embankments and cuttings shall be surfaced with this natural material. This will form a stable surface of vegetation capable of resisting erosion and avoid the need for re- seeding. 16. All excavated material shall be relocated into depressions and the new embankments. None shall be transported off-site.
2.10 Wind turbine construction programme
The detailed turbine construction programme will be issued at the time of construction, but can be summarised as follows. Cranes will be needed to offload from the transporters and to lift and assemble the components, and a large 350T telescopic crane will be required for assembly:
1 Deliver and install the transformers into the foundation;
2 Erect the lower tower sections directly off the trailer onto the foundation;
3 Deliver the upper tower sections and the nacelles to the site;
4 Erect the upper tower sections and nacelles;
5 Deliver five sets of blades to the site and assemble onto rotors;
6 Lift and install the rotor assemblies onto the turbine nacelles.
7 Demobilise all lifting equipment and clear the site.
This would be the optimum and most efficient construction sequence, though it should be recognised that the weather at the time of construction may impact upon the erection programme. Full consultation will take place with the local community to minimise disruption.
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2.11 Operation and maintenance
Operations and maintenance will be completed by the manufacturer under the control of Hammars Hill Energy Ltd. Over the operational lifetime of the project the wind turbines will require periodic inspection to maintain the condition of the machinery and structures. There will be an initial period during which it is expected that fault-finding and system fine-tuning will take place on a weekly basis, leading to a quarterly inspection and maintenance programme. In addition, there will be an annual service to check and inspect all moving parts, with full overhaul of each wind turbine completed at this stage.
There is no gearbox in this design of turbine, reducing maintenance and service requirements. The blade and main brake activation system are under hydraulic control; it is to be expected that the hydraulic oil will be replaced on a five-yearly sequence.
Modern wind turbines are well engineered and are designed to operate on extreme sites for over twenty years. Consequently major failure of the turbine components is not predicted during normal operating conditions and accordingly the possibility of component failure, including damage to blades or towers, is extremely unlikely to occur. In any event the project is located well away from housing, with only limited access to the site. The probability of members of public being at risk of harm from the turbines during normal operations and from the maintenance programme is therefore extremely unlikely.
2.12 Decommissioning
Wind turbines are temporary structures, and the expected operational lifetime and the period of the planning application is 20 years. At the end of this period the turbines will be removed from site, although it is likely that the site will continue as a windfarm. Any subsequent development would be subject to the normal planning process.
It is proposed that the stone used to form the hardstanding would be removed, and the foundations soil covered and landscaped at the end of the project. To ensure that no structure is visible, the foundations have been designed to be below ground level.
The steel, other metals and oils within the structures will all be recycled. The blades are classed as standard waste and would be handled through the normal disposal system. The improved access track is a useful asset for the farm and will be left in place. The cost of decommissioning the wind turbines is estimated at £8,000 per machine, with most if not all of this cost recovered from the scrap and recycle value of the material itself.
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3 Socio-economic benefits and planning issues
3.1 Economic Benefits; An Introduction
The wind energy industry in Orkney has already demonstrated an ability to generate significant social and economic benefits for the Islands. The existence of the extraordinary community of expertise in Renewable Technologies, now based in Stromness, can be traced back to the first developments on Burgar Hill in the 1980’s.
In addition to the creation of an intellectual resource, many valuable jobs have been directly created and sustained in Electrical, Mechanical & Civil Engineering, Project Design, and Environmental Consultancy. Orkney contractors, suppliers, and service providers have all had the opportunity to participate in these developments, and Orkney has benefited widely from the economic activity thus generated.
The Hammars Hill Wind Energy Project (HHWEP) has been developed in accordance with the stated aims of the Orkney Development Plan (The Orkney Structure Plan 2001 & the Orkney Local Plan 2004), and in the light of the Draft Supplementary Planning Guidance (Onshore Wind Energy Development) published on the 16th November 2007.
There has been significant consultation with the statutory consultees, the local community and with the Evie & Rendall Community Council. A pamphlet describing the project was published in January 2007 and widely distributed, and a further pamphlet, describing changes made to the project as a result of earlier consultations, will be published and distributed to coincide with the completion and submission of the Planning Application. It is also proposed to hold a public meeting in Evie immediately upon publication of the Planning Application.
HHWEP is a privately funded local windfarm, providing significant financial returns to all members of the Orkney community wishing to participate; there are no restrictions to involvement in the project. This project complements the grant-supported community wind turbines proposed for the outer isles, and provides a direct income stream for participants.
3.2 Energy Output
Assuming production at 45% of average capacity factor, the annual output of 5 Enercon E44 Turbines, sited on Hammars Hill as per this proposal, is estimated to be: 17,739,000 kWh. This equates to a project life-time (20 years) output of 354,780,000 kWh, enough electricity to power 3,500 homes.
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3.3 Environmental Benefits
The net environmental benefit of a Renewable Energy Project (whether the project will supply more energy during its operating life than the energy needed to manufacture, install, operate, & dispose of it, and, if so, by what margin?) is discussed in terms of “Cumulative Energy Expenditure”, “Energy Payback Time”, & “Harvest Factor”. The value of these factors will be unique to every project, varying according to the specific characteristics of the site, the ground conditions, accessibility and proximity to the grid connection point, the wind speed, and the turbines. An assessment of the Hammars Hill Site has been undertaken as follows:
Cumulative Energy Expenditure Ground Conditions on the Hammars Hill site can be characterised as excellent for the purpose of providing foundations, hard standing and access between turbines. Access to the site requires the widening of 1km of existing road, and the construction of a further 2km of new access road. With the exception of 150 – 200 metres, which has been identified, this will be a straight-forward Civil Engineering task. Grid Connection, for the Hammars Hill Project is located at a distance of 1km from the nearest turbine and 1.8km from the furthest. No additional strengthening of the Grid is required to enable the Hammars Hill connection to be made. The impact of site specific factors on the Cumulative Energy Expenditure Calculation, for the Hammars Hill site, is thus comparatively favourable.
Energy Payback Time With an average wind factor of 9.6 meters per second the Hammars Hill Site has the potential to be exceptionally productive, and, on the basis of comparison with detailed Energy Payback Time calculations carried out elsewhere by the Turbine Manufacturers, the Developers confidently expect that the Payback Time for these turbines on this site will be significantly less than 3 months. For the purpose of the calculation of the site’s “Harvest Factor” it is the Developers’ view that a 3 month Energy Payback Time represents a conservative and safe estimate of likely performance of the E44 turbine on the Hammars Hill Site.
Harvest Factor On the basis of the conventional assumption of a 20 year operational life, the Harvest Factor for the Hammars Hill Site can therefore be calculated to be 80:1. For every unit of energy expended in the manufacture, transportation, erection, installation, operation, decommissioning & disposal of the Installations associated with the Hammars Hill Wind Energy Project it is anticipated that the HHWEP will generate 80 units of clean energy.
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3.4 Benefits to Orkney and the Orkney Economy:
Employment i With the single exception of the Archaeological Survey, the applicant has been able to employ Orkney based consultants for all aspects of the planning process. ii Similarly, it is the Developers intention to employ local contractors for all aspects of the construction phase. The project, as designed, is within the capabilities of existing Orkney engineering resources. iii It is intended that project management will be retained in Orkney. iv This project will contribute significantly to the “critical mass” of community and locally-owned turbines required for the training and deployment of a local Service Team. This would represent a highly desirable improvement on the initial arrangement, which is for Enercon’s Orkney Turbines to be serviced from the North East of Scotland.
Investment Opportunities i Hammars Hill Energy Ltd, the intended developer, is a locally owned Private Limited Company. Subject to the achievement of Planning Consent, the Directors of Hammars Hill Energy Ltd intend that there should be opportunities for equity participation in this project by local Investors, large or small. ii To this end, the Directors have agreed: a. that the minimum shareholding in the Company should be £100; b. that provision shall be made for local community investment in the project, should that be desired; & c. to welcome investment on behalf of the people of Orkney from that part of the Reserve Fund designated by Orkney Islands Council for the purpose of participation in local Wind Energy Projects. iii It is the stated objective of the Developers that, by these means, the greatest possible proportion of the benefits of the proposed development should be retained in Orkney.
Energy Security
Electricity demand on the Orkney grid varies between a peak of 31MW in winter and a summer low of 8MW. With a rated output of 4.5MW, and an average capacity factor of 45%, HHWEP will contribute significantly to Orkney’s electrical grid capacity. Developments in energy storage technologies (Hydrogen & Fuel Cell technologies, for example), hold the promise that this contribution can be extended to Orkney’s general energy needs.
Rates & Taxes
HHWEP claims no special merit for contributions to the national exchequer, but Business Rates payable over the life time of the project (20 years), under present arrangements, are anticipated to be in the region of £650,000, while the Corporation Tax yield is estimated to exceed £1,600,000.
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3.5 Local Benefits; Evie & Rendall
Agricultural Diversification The Project will contribute significantly to the viability of two local Farms, which will be in direct receipt of rent and way-leave payments from the Developers.
Community Fund Following industry standard practice, the Developers have undertaken to make £2,000 per annum, per MW, available to a Community Fund to be administered by Evie & Rendall Community Council. This will amount to an annual payment of £9,000.
Interpretation Centre; Tourism & Employment There is currently no actively managed Wind Energy Interpretation Centre in Scotland. It is the applicants’ intention, subject to the statutory consents, to establish a Tourist resource at Grid Reference HY 384227, with views over Eynhallow sound, accessed by the access road to the Turbines and linked to the existing Farm Footpath network. This facility would include a combined Wind Energy, Farm, and Natural Environment Interpretation Centre, a Restaurant & Craft Shop, Parking & Toilet Facilities. The Developers have agreed that telemetry from the Wind Turbines can be relayed to the Interpretation Centre, and discussions have been initiated with the RSPB to provide Live CCTV images from the West Mainland Moorland Site. Opening between April & October, this facility can strengthen the Tourism resource of Orkney, and particularly of Evie & Rendall, and can provide valuable local employment: 1 Full time, and 4 seasonal jobs are envisaged. Note that the centre is not part of the current turbine planning application.
Educational Resource It is envisaged that the Interpretation Centre outlined above, should be available as an educational resource to the Evie Primary School, and to the wider Orkney school system.
3.6 Economic Benefits; A Summary
It is argued that, because the engineering challenges are the simplest, the energy payback time the shortest and the harvest factor the greatest, onshore wind energy is the most environmentally beneficial of the renewable technologies. Hammars Hill is a particularly productive site, presenting no complex engineering challenges, and so scores very highly in terms of the comparative measurement of environmental benefits. The project represents an opportunity to make a significant and efficient contribution to “Energy Security” for Orkney, in an age when this is a real issue. Hammars Hill Energy Ltd, the intended developer for the site, is a locally based and locally owned Company, committed to the wide distribution of the project’s financial benefits within the Orkney Community. The Applicant and the Developers take an imaginative view of the tourist and educational potential of the site, and are committed to maximising its amenity value to the local community.
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3.7 National Planning Context; SPP6
National Guidance
The project has been designed and planned using the recommendations and advice contained within Best Practice Guidelines for Wind Energy Developments (BWEA), Scottish Planning
Policy SPP6: Renewable Energy(Scottish Government 2007), Planning Advice Notes PAN 45:
Renewable Energy Technologies (Scottish Government 2002), PAN 56: Planning and Noise (Scottish
Government 1999), PAN 58: Environmental Impact Assessment (Scottish Government 1999) and PAN 68:
Design Statements (Scottish Government 2003), the SNH Guidelines on the Environmental Impact of
Projects (SNH Publications), the DTI Final Report on the Assessment of Noise from projects (ETSU
1996) and the Guidelines on Wind Energy and Aviation Interests from the Defence and Civil
Aviation Interests Working Group(ETSU 2002). The project has also considered Scottish Planning Policy 15: Planning for Rural Development, and PAN 73: Rural
Diversification(Scottish Government 2006).
Diversification The overarching aim of the Scottish Government, as detailed in the above policies and advice notes is to have a prosperous rural economy, with a stable or increasing population that is more balanced in terms of age structure, and where rural communities have reasonable access to good quality services. SPP15 and PAN73 in particular indicate that planning authorities should take a more welcoming stance to development in rural Scotland and proactively enable and help create opportunities for development in sustainable locations, and in addition rural diversification should be embraced to help businesses and farmers start new enterprises in appropriate circumstances and at an appropriate scale; “There are many activities that make a valuable contribution to the rural economy that are less immediately obvious such as…quarrying, waste disposal, hydro-electric schemes and wind turbines” (PAN73). .
SPP6 - Targets In 2007 the Scottish Government published SPP6, showing planning authorities how they should manage the process of encouraging, approving and implementing renewable energy proposals when preparing development plans and determining planning applications. The Scottish Ministers have set a target of generating 40% (since quantified as 6GW) of Scotland’s electricity from renewable sources by 2020 and confirmed that this target should not be regarded as a cap. The importance of using clean and sustainable energy from renewable sources will continue to increase as a result of global imperatives to tackle climate change and the need to ensure secure and diverse energy supplies. The Scottish Ministers will
OSE/2825 28 Orkney Sustainable Energy Hammars Hill February 2008 continue to support the full range of renewable generation technologies to enable Scotland to realise its considerable renewable energy potential.
SPP6 - Local Investment The role of local communities and renewables is discussed in paragraphs 18 and 19 of SPP6; “There is potential, particularly in rural areas, for communities to invest in ownership of renewable energy projects or to develop their own local projects for local benefit. Small scale wind farms, such as those proposed by local communities, may be able to supply electricity to the local distribution network and more widely on the transmission network.” SPP6 then goes on: “Planning authorities should put in place positive policies to enable communities to develop such initiatives in an environmentally acceptable manner.” Local investment opportunities are further discussed in paragraph 19: “A range of benefits are often voluntarily provided by some commercial developers to communities in the vicinity of renewable energy developments. These can include Community Trust Funds which support a variety of projects, including energy conservation initiatives, within the local community or opportunities for local communities, as a whole, to invest in developments with local long term environmental, social and/or economic benefits.”
3.8 Structure Plan context
In December 2001 Orkney Islands Council published the Orkney Structure Plan written statement (Orkney Islands Council 2001). The Structure Plan sets out the strategic framework for the development of land in the county over a ten year period. In section 2.3, the strategy explains that one of the key underlying principles is that of sustainable development, encompassing social, economic and environmental goals, and states that planning decisions should favour the most sustainable option, and promote development which safeguards and enhances the long term needs of the economy, society and the environment.
The provision of renewable energy is discussed in section 10: “To encourage renewable energy developments where environmentally acceptable”, in section 10.17 the strategy indicates that “…there is considerable potential in Orkney to harness various sources of renewable energy, including wind, wave and tidal power.”, and in section 10.19: “Whilst the renewable energy resource is undoubtedly significant, albeit under utilised, its development must be reconciled with the need to safeguard the environment, and with the capacity of the electricity grid system to accommodate additional capacity”.
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The following is the relevant extract from the Structure Plan:
3.9 Orkney Islands Council Local Plan
The Local Plan, approved in February 2002, favourably considers renewable energy facilities provided there are no significant adverse impacts on nature conservation areas, the landscape character, to neighbours, archaeological, historic or cultural interests and no significant impact upon aircraft activity and other telecommunication interests. Policy LP/U7 sets out how the impact of wind power should be considered in Orkney, and the following is the relevant extract:
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3.10 Draft Planning Guidance
Orkney Islands Council have attempted to produce a set of guidelines for developers of renewable energy projects, with draft supplementary planning guidance published in 2005, further revised in October 2006 and January 2007, then reformulated and issued as Draft Supplementary Planning Guidance (Onshore Wind Energy Development) published in November 2007. The latest draft makes no reference to local ownership, and indeed this Planning Guidance does not appear to achieve the recommendations of the Scottish Government as put forward in SPP6, and only considers large scale developments.
Notwithstanding the weaknesses within the latest draft planning guidance, the Hammars Hill project can be considered a locally owned community development: “In regard to larger scale projects, developments can be financed in a variety of ways, including commercial enterprise and locally owned or community based partnerships. Whether as individual installations or as clusters involving some form of community involvement through an equity share or a community share in a number of turbines which make up a larger commercial development, larger forms of production offer communities, cooperatives, small businesses and local residents the opportunity to harness local energy, and generate electricity whilst protecting their own environment and stimulating their local economy. Community based developments can prove useful in rural development, as they can help alleviate fuel poverty when combined with affordable housing schemes, can provide extra income, and provide employment opportunities.”(OIC Planning Guidance)
In the context of the draft guidelines, the Hammars Hill project has no significant adverse effects on the natural heritage and biodiversity of Orkney, has insignificant effects on the landscape character of Orkney, has avoided significant visual impact by ensuring the turbines are of the correct scale for the landscape, have low impacts upon neighbours, have avoided significant adverse impacts upon the historic environment, have avoided impact upon hydrological and geological features, have been located well away from any airport or airfield, and have avoided ancillary development by using existing access tracks and field drains wherever possible, and ensuring all site cabling is buried. It is recognised that wind turbines are temporary structure that will be removed from the hill at the completion of the project. The Developers also fully recognise the benefits of partnership and community involvement, and consequently have proposed a structure of local community investment. It is felt that the project fits well within the aims and vision of Orkney Islands Council, and is a good example of both a sustainable development, and important rural diversification.
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4 Summary of environmental impacts
The environmental impacts and benefits of wind energy projects are largely recognised, however both the specific implications of constructing a wind farm at Hammars Hill and the cumulative effects of the wind energy projects constructed and proposed for other parts of Orkney require consideration. The Hammars Hill Wind Energy Project is located on a moorland hilltop to the south-west of the A966 between Evie and Rendall. The wind turbines are to be located behind the ridge when viewed from the east, with the foundations installed in glacial till and upon the underlying sedimentary rock.
From the outset the applicant has expressed the desire to minimise the environmental impact of the project, with independent studies completed as part of the assessment. Consideration of the Orkney Islands Council supplementary planning guidance indicated that this project can be considered a small locally-owned windfarm, with the turbines becoming an integral part of, but not dominating, the surrounding countryside. Assessment of the ecology across the area has been completed, including a breeding bird survey, an assessment of mammals and analysis of soil and bedrock at the turbine location. An assessment of the risk to archaeology has been conducted, noise impact has been calculated using a cumulative geometric spreading calculation, and the risk of shadow impact at neighbouring properties has been assessed.
The following potential environmental impacts have been addressed, summarised below, with the proposed controls and mitigation covered in part 5 of this section of the report: • visual impact upon the landscape • ecological impact • impact on archaeology • geological and hydrology impact • carbon emissions during construction • pollution impact during construction and operation • disturbance from noise • shadow flicker nuisance • radio communications interference
Impact upon sensitive habitats has been avoided, impact upon bird species will not be adversely significant, and there is no known archaeology in the area. Noise, shadow flicker and pollution impacts have been quantified and are also insignificant and the wind turbine model and the windfarm layout has been determined to provide a good and appropriate fit to the landscape.
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4.1 Visual impact upon the landscape
A Landscape and Visual Impact Assessment has been completed, Section 2, and to aid assessment of the visual impact of the development, a series of wireframe images and photomontages has been produced, Volume 2 of the report. Maps showing the Zone of Theoretical Visibility of the project have also been produced, showing the locations where the turbines could be seen from, notwithstanding any visual barriers from buildings. The turbines present a simple linear relationship to the landform, the project has been positioned back from the road, and the site switchgear building is located away from the turbines and positioned adjacent to derelict buildings next the public road.
The site is not subject to any landscape designations, and the landscape assessment concludes that the site is well screened from the West Mainland National Scenic Area and from the Heart of Neolithic Orkney World Heritage Site.
Impact on Landscape Character
The turbines are to be located upon a moorland hill and have been assessed as having Low and Medium significant effects on the site landscape elements. There are no visual impacts upon the Heart of Neolithic Orkney World Heritage Site, with only a Negligible/Low indirect impact upon a very small part of the Orkney West Mainland National Scenic Area.
There are three properties in Orkney that are registered as Gardens and Designed Landscapes; Skaill House in the West Mainland, Balfour Castle on Shapinsay and Melsetter House in Longhope, Hoy. The maps showing the Zone of Theoretical Visibility demonstrate that there are no visual effects upon the settings of Skaill House or Melsetter House, with only marginal indirect impacts upon Balfour Castle and Gardens due to prominent landform barriers.
There is a broad range of Listed Buildings, Scheduled Ancient Monuments (SAM) and other properties in care in this part of Orkney, although none at the windfarm site. There are no direct impacts upon any Listed Building, SAM or Property in Care. Marginal indirect impacts occur upon the setting of the Broch of Gurness, with views of the turbines mainly blocked by landforms.
Zone of Theoretical Visibility
Zone of theoretical visibility (ZTV) diagrams were generated using the Windfarm programme along with Ordnance Survey gridded topographic ‘Panorama’ data. These show the
OSE/2825 35 Orkney Sustainable Energy Hammars Hill February 2008 theoretical extent of visibility of the project, measured to uppermost tip height, assuming very clear weather conditions. A 25km boundary has been chosen, in accordance with the recommendations in ‘Visual Assessment of Projects: Best Practice’ SNH, though it should be considered that in very clear conditions the site may be seen from areas beyond this boundary. The ZTV is largely contained within 5 to 10km from the site, with only a marginal impact upon the western part of Mainland Orkney, reflecting the barrier effects of the moorland hills between Finstown and Evie. Maps produced to predict Zones of Theoretical Visibility and wireframe analysis indicate that the development would be well screened to the west of the site, with the turbines mainly visible from Rousay and Evie to the north, the communities of Rendall, Hackland and Norseman to the east and from the outskirts of Kirkwall.
Impact on Visual Resource
The significance of the impact of the development on the area was assessed by establishing 25 viewpoints, by assessing the sensitivity of the viewpoint and assessing the significance of the magnitude of change to the view. Each viewpoint was assessed in turn and graded from Negligible to Very High, taking into account the quality of the landscape, the value of the landscape, the presence of any discordant or prominent features, and the type and number of potential viewers. The viewpoints were selected to reflect a variety of views and to include those experienced by motorists, residents and visitors, across a range of landscape types and at varying distances from the site. Only viewpoints that fall within the ZVI have been used.
Views from the main population centres would be mainly of a distant nature. Field study has confirmed that the most significant views are the scattered housing at Hackland and from the village of Evie. Views from the A966 would be mainly of an indirect nature, with the long straight between Finstown and Evie having the greatest sequential impacts; direct views to the turbines occur only at this section of the road.
The use of relatively small turbines results in mainly Low and Medium Significance impact at the viewpoints. The Enercon E44 wind turbines are in proportion and fit well with the landscape. In no views do the turbines appear to dominate or diminish the apparent scale of the landscape nor do they adversely affect the quality of views to any significant extent.
Figure 4.1 is a map showing the visual impact of the project upon the various islands of Orkney, and Figure 4.2 shows the location of the viewpoints. Cumulative, sequential and successive visual impacts are also explored in the main body of the report, showing the areas where the Hammars Hill development could be seen in conjunction with all other wind energy projects either constructed or in planning in Orkney
.
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OSE/2825 Figure 4.1 - Zone of Theoretical Visibility 37 Orkney Sustainable Energy Hammars Hill February 2008
OSE/2825 38 Figure 4.2 - Viewpoints Orkney Sustainable Energy Hammars Hill February 2008
4.2 Ecological Impact
Setting and management of the development site The proposed position for the development is on the upper slopes of Hammars Hill, lying on the boundary of Rendall and Evie in the West Mainland of Orkney. The hill stands to a maximum of 165m above sea level and extends north-westwards from the West Mainland hills, being connected to them by a shallow saddle, with low, cultivated ground on the other three sides. The access route would follow the existing farm access for about a kilometre and then branch up the hillside to link each of the turbines along the upper, northern slopes.
The land use in the vicinity is mainly for stock grazing and nature conservation. The development site itself is on a moderately to heavily grazed hillside, which has not otherwise been agriculturally improved. The on-site vegetation least affected by livestock is the blanket bog towards the top of the hill, on which most of the development will lie.
The boundary of the Orkney Mainland Moors Special Protection Area (SPA), which overlies that of the West Mainland Moorlands Site of Special Scientific Interest (SSSI), is about 370m from the westernmost turbine position. These two designations are primarily for moorland breeding birds, the key species being Red-throated Diver, Hen Harrier and Short-eared Owl. Other important birds are the Arctic and Great Skuas, which both have very limited breeding distributions in the UK, and scarcer birds of prey such as Merlin and Peregrine. Icelandic- breeding Greylag Geese winter in Orkney in increasingly high numbers, so that internationally important numbers may occur in many places around the county.
Watercourses arise as flushes at various points on the middle and lower slopes of the hillside, and are mostly canalised along ditches until they feed into the Burn of Woodwick in the valley below. Otters are likely to be present at times, at least along the main burn.
Aims and scale of ecology survey work Survey work was carried out on and around the Hammars Hill development site between March 2006 and December 2007. Information has been gathered regarding the vegetation, birds and mammals, with the following aims: • to produce a vegetation map; • to survey the breeding birds close to the site; • to document the scarcer raptors and divers that nest in the vicinity; • to gauge the extent to which cited species from the SPA and SSSI, and Greylag Geese, might use or overfly the site • to locate any resting places of Otters near the site.
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Fieldwork for birds covered a full thirteen months from April 2006 to April 2007, with additional watches specifically for divers in June to August 2007. More than 280 hours were spent in the field on bird work, with 30 hours dedicated to vegetation and 6 hours to Otter survey. The timing and number of hours spent on each survey are summarised in Table A below.
Table A. Timing and hours for ecological survey work [VP= vantage point]
J F M A M J J A S O N D Hours Vegetation 30 Otters 6 Main VP survey 241 Diver VP 2007 20 Owl work 9
Birds Breeding birds 11 Total fieldwork hours 317
Vegetation
The vegetation types were surveyed and described using standard National Vegetation Classification (NVC) methods.
Peat, underlain by clay, covers the top of Hammars Hill and the gentler slopes of the hillside down to the foot of the hill. The deeper peat supports types of bog vegetation, of which the commonest form found on-site is the heather and cottongrass-dominated M19 Calluna vulgaris-Eriophorum vaginatum blanket bog, particularly the M19a Erica tetralix sub- community.
Steeper slopes have a thinner covering of peat and support heath vegetation or grassland derived from heath. There is much groundwater seepage on the lower slopes, providing the source of both acid and base-rich flushes, and areas of flushed heath and grassland.
Most of the site is managed by sheep and cattle grazing. This has affected the vegetation greatly, creating acid grassland and heath/grassland mosaics from what was formerly heath on the drier slopes, and also bog/grassland intermediates on some of the wetter slopes. These effects are particularly apparent closest to the point of access for livestock from adjacent improved grassland and from the steading at Neigarth. The bog vegetation on the upper slopes, further from stock access and not so attractive for grazing, has been less affected by grazing impacts and is in relatively good condition.
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All of the proposed turbine sites and much of the linking access road would be on M19 bog vegetation, including some in good condition on the summit plateau and some in poorer condition lower down. The access route up the hillside would mainly be along the length of a steep-sided ditch and across harder-grazed acid grassland and its transitions to bog and heath (including U6 Juncus squarrosus-Festuca ovina grassland and M23b Juncus effusus/acutiflorus rush-pasture, Juncus effusus sub-community).
KEY:
Ungrazed or lightly grazed heath and mire
Grazed heath and mire
More or less unimproved grassland and rush pasture
More or less improved grassland and arable
Planted trees & bushes and gorse scrub
Turbine position
Access route to be widened
New access route
Cable route
SSSI & SPA boundary
0m 500m
Figure 4.3. Simplified vegetation map of Hammars Hill
Otters
A survey of the watercourses to the east of the A966, out to 500m from the proposed access route and turbine positions, found several Otter signs, all from along the course of the Woodwick Burn. As well as spraint (droppings) in typical locations by crossing points etc, there was also one possible temporary resting place under a boulder by the burn, situated at about 200m from where the existing farm access route would need to be widened.
Small fish are known to occur in some of the lower ditches, and Otters probably forage along them occasionally, but the upper ditches nearest the site, including the stretch that will accommodate the new track, are of very low (or nil) potential for Otters.
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Breeding birds Of the three SPA species, only the Short-eared Owl nests regularly within 1km of the development – one pair was located from this survey work at about 400m from the nearest turbine position in both 2006 and 2007. At about 1km distance there are two more pairs of owls and a former site for Hen Harriers (not used since 2004). At about 2km there are up to five more pairs of owls, up to three more Hen Harrier sites, and up to twelve pairs of Red- throated Divers.
Merlins breed irregularly at about 2km with another (possibly alternative) site at 2.5km. The nearest Peregrine eyrie is 8km or more distant. Of the commoner UK raptors, one or two pairs of both Sparrowhawk and Kestrel breed regularly within 2km. One or two pairs each of Arctic and Great Skuas may nest from 1 to 2 km away.
The estimated number of pairs of species found breeding within 500m of the turbine positions and access route are summarised in Table B below. Apart from the Oystercatcher, Lapwing, Redshank and Mallard, which were found mainly on the lower farmland, these birds were mostly associated with the upper slopes.
Table B. Brown & Shepherd survey results – breeding species within 500m of the turbine positions and access route, with estimated number of territories.
Waders Other
Oystercatcher 9 Mallard 1 Lapwing 7 Red Grouse2 Golden Plover 1 Skylark Scattered Snipe 10 Meadow Pipit Scattered Curlew 12 Stonechat 1 Redshank 5 Short-eared Owl1
In terms of the importance of the breeding numbers within 500m of the development site (where 1% of a geographical population is considered as ‘important’), the following apply at Hammars Hill:
• Short-eared Owl – 1 pair, SPA and regional importance (the region being the Orkney and North Caithness Natural Heritage Zone as defined by SNH); • Golden Plover – 1 pair, county importance; • Snipe – 10 pairs, locally important (West Mainland); • Curlew – 12 pairs, locally important (on the upland moors of West Mainland); • Red Grouse – 2 pairs, locally important (West Mainland); • Stonechat – 1 pair, locally important (West Mainland).
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Wintering geese Feeding Greylag Geese from the Icelandic-breeding population were present from September to April; the maximum count was of about 400 within 1km of the turbine positions, and averaged much less. Given the huge increase in numbers of these birds in Orkney, 400 would not be important at any wider scale than that of the West Mainland.
Pink-footed Geese were not seen feeding nearby, but occasionally flew over or near the site between January and April. The maximum of 255 birds flying north in April would represent more than 1% of the Orkney wintering numbers.
Birds from vantage point (VP) watches Target species for VP watches were: • the three SPA species (Red-throated Diver, Hen Harrier, Short-eared Owl); • wintering Greylag and Pink-footed Geese; • any Birds Directive Annex 1 species; • any Wildlife & Countryside Act Schedule 1 breeding species; • the two breeding skuas (Arctic and Great Skuas). Table C below summarises the number of observations of each species across the whole survey area and gives the number of observations and number of birds considered to be at risk.
Table C. Summary of flights of target species across whole survey area from timed VP watches
Species Hours season between sizes per season of watched in occurrence observation Observation Observations observations) interval during % birds at risk Total no. birds Range of flock urrence (hours season of occ- Expected main No birds at risk
Greylag Goose mid Sept – 146 303 0.5 1 – 170 3872 519 13% (Icelandic) April Pink-footed January – 7 82 11.7 1 – 120 263 260 99% Goose April Red-throated April – 158 118 0.7 1 – 7 248 13 5% Diver August Hen Harrier 145 all year 241 1.7 1 – 2 146 10 7% Merlin 13 all year 241 18.5 1 13 5 38% Peregrine 29 all year 241 8.3 1 – 2 32 18 56% Golden Plover May – 12 94 7.8 1 – 7 23 - 0% (breeding) August Golden Plover September – 51 147 2.9 1 – 250 2056 552 27% (non-breeding) April April – Whimbrel 5 137 27.4 1 – 2 7 - 0% September Arctic Skua 106 April-August 118 1.1 1 – 3 123 25 20% April- Great Skua 370 137 0.4 1 – 4 450 132 29% September Short-eared Owl 62 all year 241 3.9 1 – 2 63 - 0%
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The Great Skua and Greylag Goose were the most recorded target species overall (more than 300 flight observations) and were also the most frequently observed within their season of occurrence (more than twice per hour). Red-throated Divers, Hen Harriers and Arctic Skuas were detected on over 100 occasions, the diver at a rate of more than once per hour over the summer. Short-eared Owls and northern Golden Plovers were observed in flight once every 3–4 hours during their expected season of occurrence, breeding Golden Plovers and Peregrines every 7–8 hours, and Pink-footed Geese, Merlins and Whimbrels at lower rates still. In terms of the numbers of individuals observed at risk height close to the turbine position, by far the most numerous were those occurring in large flocks – the geese and northern Golden Plover.
As a proportion of their overall number of sightings, Red-throated Divers, Hen Harriers, and especially Short-eared Owls, had a relatively low likelihood of being at risk height close to the turbines. In the case of the divers this was because several pairs located to the north contributed many flight records, but rarely near the hill itself, and also because the regular foraging flights past the hill by two pairs to the west were usually at some distance either side of the hill. For the harrier and owl, the bulk of their flying time was spent foraging low, at less than 20m above ground.
0 m 1 km . Figure 4.4. All Red-throated Divers in transit (outgoing in red, incoming in blue); 200m radii shown in pink around turbine positions
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Over half of the Peregrines were at risk height for at least part of their flight, and over a third of Merlins. Nearly all the Pink-footed Geese observed were at risk; however, this is based on a very small sample of sightings, nearly all of which were on 19th April 2006 when three passage flocks flew northwards across the hill. Greylag Geese regularly fed to the north and south of the hill in relatively low numbers – there was regular flighting across the hill, but often at the saddle area and therefore to the west of the turbine row, hence the rather low percentage of birds at risk.
The Arctic Skuas seen were mostly thought to be in transit past the hill from the small colonies on the moors to the west. However, Great Skuas were much more numerous passing the hill, although similar numbers nest on the moors, indicating that many of the birds must have been linked with colonies further afield, probably those on Hoy.
Figure 4.4 shows all divers in transit across the area, with outgoing and incoming birds indicated by different coloured lines. Incoming flight lines were rather fewer, thought mainly to be due to birds approaching from distances and directions not visible from the vantage points. The topography of the hill has a bearing on flight patterns around it, particularly in certain wind directions. Figure 4.5 shows the Hen Harrier flights in N/NW and S/SE winds, clearly showing how birds prefer the upwind side of the hill; this was also the case for Peregrines, which frequently hung on the updraughts created in these wind directions.
0m 500m Figure 4.5. Hen Harrier flights in N/NW and S/SE winds (blue lines in N/NW winds red lines in S/SE winds); turbine positions and 200m & 500m zones shown.
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Of the non-target species, the most important is the Raven. Fieldwork revealed a roost that totalled up to 170 non-breeding birds, a large proportion of the total Orkney numbers. There were often tens of birds remaining around the hill during the day, and these seemed to attract the young Peregrines, which flew with them on the updraughts for up to forty minutes at a time. A large proportion of the collision risk to Peregrines was to young birds engaged in chasing flights with Ravens.
Potential impacts The main potential impacts from an onshore wind farm are habitat loss, disturbance of birds during construction, displacement of birds from operational turbines and collision fatalities. At Hammars Hill there would be loss and disturbance to semi-natural habitats. About 0.75 ha of grazed blanket bog vegetation would be lost under turbine hard-standings and the access route, with up to a further 3 ha disturbed alongside or subject to some alteration of drainage. The disturbed or altered vegetation would remain semi-natural but would probably tend towards drier, more heathy or grassy vegetation types. Much smaller amounts of other semi- natural habitats (wet heath and acid grassland) would be lost under the access route, where grazing pressure has already had a considerable effect. Up to 0.1 ha of ungrazed trackside verges would be lost to access route widening. Disturbance to drainage could very well occur along the route of the cable, and this would particularly affect the wet habitats through which it crosses i.e. basic flushes and flushed wet heath.
Disturbance during construction would probably have a direct effect on the nesting owls and waders around the turbine positions if construction were to occur in the breeding season. There could be an indirect effect on harriers, since the males are often supporting more than one female, and any adverse effect on the males’ foraging during the critical early part of the season might affect the ability of several females to come into breeding condition. In the non- breeding season, when foraging harriers and owls can range much more widely, any effect would be negligible.
Displacement of birds due to the presence of the turbines themselves may affect breeding and foraging birds. This is unlikely to affect farmland foraging birds at Hammars Hill because the turbine positions are located away from the cultivated fields where flocks occur. It is also considered insignificant for foraging raptors, given the large foraging areas used by these species. It is possible that the closest breeding pairs of Golden Plover, Curlew and Snipe might be displaced from the vicinity of the turbines.
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Collision risk workings have been carried out for all target bird species that were observed, from timed VP watches, flying at risk height within 200m of the turbine positions; these are summarised in Table D below. The workings depend on how representative the observations were (which might vary between species), and incorporate various assumptions, such as observer efficiency, operational efficiency and most critically the avoidance rate (hence ranges of avoidance rates are shown for most species). These assumptions all work as multipliers within the calculation. Although the aim has been to use precautionary but reasonable figures, the resulting collision rates must be seen to be subject to wide/very wide error margins.
Table D Summary of predicted collision rates for target species, showing the avoidance rate (or range of avoidance rates) used. NB. these figures are subject to wide, or very wide, margins for error
Species Relevant level of No. of Avoid- Predicted Predicted legislative or birds obs- ance no. no. of geographical erved at rate fatalities years importance at risk used per year between Hammars Hill fatalities Greylag Goose Local 519 99% 1.60 0.62 Pink-footed Goose Orkney 260 99% 0.63 1.58 95% 0.29 3.41 Red-throated Diver European 13 97.5% 0.15 6.82 99% 0.06 17.05 97.5% 0.06 16.33 Hen Harrier European 10 99% 0.02 40.82 Merlin Regional 5 95% 0.06 15.75 Peregrine (adult) Regional 1-4 95% 0.02 48.34 Peregrine (first year) Regional 14-17 95% 0.25 3.93 98% 2.15 0.47 Golden Plover (non-br) Orkney 552 99% 1.07 0.93 98% 0.17 5.77 Arctic Skua Regional 25 99% 0.09 11.54 98% 1.37 0.73 Great Skua Regional 132 99% 0.68 1.46
The actual significance of additional fatalities depends upon their effect on the population as a whole – a simple comparison may be made to the ‘background’ mortality and survival rates for each population. It is the percentage changes in these that can then be used in the assessment of impacts. It may be considered that there will be a negligible effect on any species where the mortality of the relevant population is increased by less than 1% of its background value, and this is the case for all species at Hammars Hill except Red-throated Divers (at conservative low avoidance rates) and young Peregrines (up to one year old).
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4.3 Potential disturbance to archaeology
Site Investigations Walkover surveys of the sites and the vicinity were conducted in 2006 and 2007; Section 4 is the detailed report and assessment of impact. The objectives of the surveys were to identify and describe any known archaeological sites and to anticipate the potential for unknown sites within the immediate environs of Hammars Hill, to assess the potential impacts of the developments, and to identify measures to mitigate any adverse impacts. The following resources were used: • The National Monuments Record of Scotland, accessed through the CANMORE database;
• Online search of the Ordnance Survey 1:10,560 first edition map of 1882;
• The Orkney Sites and Monuments Record housed at the Orkney Archaeological Trust;
• The Orkney Archaeological Trust aerial photograph collection;
Two walkover surveys of the development area and the immediate surroundings.
Observations There is a lack of recorded features in the area, and a comparative dearth of named features on old and current maps. Surface and sub-surface investigations suggest that the probability of archaeological features or deposits within the development footprint is minimal. This is perhaps an unexpected outcome, as an initial encounter with the hill brings home its impressive and widely visible position within the landscape and its proximity to the intensively settled and exploited coastal strip. For several millennia, communities within that strip would have been well aware of the hill alongside their territories, yet there is almost no tangible sign, apart from two possible prehistoric tumuli in a hidden micro-location, that the hill ridge was included within the activities of these communities. This applies in terms of fixed location buildings, such as cairns or domestic complexes, and for more peripheral features such as fieldwalls and land boundaries. The pair of possible prehistoric tumuli at HY 38969/22755 and 38965/22737 lie some way east of the upper portion of the cable route, and might only be affected by plant transit rather than direct construction activity.
A further observation is that there is no sign of any process which might have led to the concealment or destruction of earlier remains. The only exception may be the lower slopes of the hill, which have probably been broken in at some stage by ploughing, perhaps relating to the Neigarth and Cupper crofts. Otherwise the hill appears untouched; there are no fieldwalls which might have sourced material by stone-robbing, and its upper slopes provide sufficient gradient to remove the need for buried field drain systems. Apart from the open drainage
OSE/2825 48 Orkney Sustainable Energy Hammars Hill February 2008 gullies on the lower slopes and a network of fences mainly along the ridge, there is nothing to indicate any degree of disturbance or the potential for archaeological loss.
The explanation, or at least the context for a series of explanations, is very much derived from the severe geology, with post-glacial bedrock so close to the ground surface that conventional topsoil development processes could never take any real hold. Instead a thin skin of peat seems to have been the only covering. The visual indications from the walkovers and the data from the test pits confirm this scanty covering, and provide a consequent indication that any significant deposits or features would show some degree of surface indication. The hill does not, at least within the surveyed areas and spot locations, show any sign of deeper pockets or tranches of peat which might conceal buried features. In summary, the sub-surface geology both determines the barren nature of the hill and the subsequent degree of confidence with which the lack of observed features can be regarded as a true picture.
Conclusions
It can be concluded that there is only a very slight possibility that groundbreaking work for the cable route at Hammars Hill may result in the uncovering of unknown archaeological remains. The requirement for an archaeological watching brief is thus unlikely, and guidance on the this matter from the Orkney Islands Council Archaeologist would be welcome. Should the groundbreaking work reveal any underground structures then, depending on the nature of the discovery and its condition, possible actions would include a quick removal by excavation and recording or a rerouting of the cable to avoid the discovery, leaving it in situ.
4.4 Impact upon Geological and Hydrological features
Solid Geology and Superficial Deposits
An assessment of the geology and the hydrological features of the area was conducted with reference to the One Inch Geological map of Scotland, sheet 119 produced by the British Geological Survey. This map identified various layers – artificial, landslip, superficial and bedrock geology. This part of Orkney has no artificial or landslip aspects to the land, however the assessment did indicate the extent of peat deposits and boulder clay in the area. These extend over much of the West Mainland hills, with further peat overlying the boulder clay covering the coastal basin flagstone bedrock east of the hills.
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The basement rocks of Orkney are a mixture of granite, gneiss and schists, which formed part of the Caledonian mountain chain 400 million years ago. These rocks originally enclosed the Lake Orcades basin which became the focus of erosion and the deposition over time. This sediment formed Old Red Sandstone, which now largely obscures the basement rock complex. Subsequent tectonic activity caused the sediments to become folded and faulted, creating a range of hills which was then subjected to erosion and submergence; the Orkney Islands represent the higher remains of these hills. Hammars Hill thus consists of gently sloping sedimentary rocks, comprising of Stromness and Rousay flagstone.
The solid geology of Orkney was modified by glacial action during the ice ages, the last of which reached its maximum extent 18,000 years ago. The main effects of ice movement was generally to smooth out the topography and to deposit glacial till boulder clay, however on the southern side of Rousay and to a lesser extent on Hammars Hill, the ice scouring has emphasised terracing in contrast to smoothing effects elsewhere. Poorer climatic conditions in the post-glacial period has resulted in deposition of peaty soils, and on Hammars Hill this ranges from 300 to 900mm in depth, and is identified as thin peat with Olrig series superficial deposits, overlying a layer of clay varying from 2600mm in the valley floor to 250mm at the higher levels.
Hydrological features; Risk of Peat Slide
The Hammars Hill area has a relatively low average rainfall of around 1000mm per annum, similar to that of the east coast of Scotland; rain volumes are low due to rainshadow effects. The main hydrological feature in the area is the Burn of Woodwick, which runs along the bottom the valley at Savisgarth, approximately 500m to the north-west of the turbine positions. The north western face of Hammars Hill has various field drains that feed into Woodwick Burn, one of which is to be used as the site access track. This drainage ditch has a sloping flagstone base and forms the start of the access route to the upper reaches. The flow in this drainage ditch becomes a trickle in the summer months. The banks of this ditch are stable and do not appear to suffer from annual drying out, indicating that the peat has sufficient strength to resist slumping.
Peat is a biogenic deposit which when saturated consists of about 90-95% water. The organic content of the solid part of peat is very high, and is made up of the decayed remains of vegetation that has accumulated over a timescale of centuries. The fact that peat can absorb such a high volume of water means that its strength properties can vary greatly between summer and winter.
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Peat slides, bog flows and bog bursts are widespread in the uplands of the British Isles, and these movements are usually triggered by heavy or prolonged rainfall. The mechanisms of peat slide involve instability of peat deposits over a rock or mineral subsurface, with slab-like failures involving a shear failure mechanism. Peat slides can result in significant movement of superficial deposits. After exceptional rainfall in October 2006, when 83mm of rain was recorded in 26 hours, extensive peat movement occurred on the east-facing slope of Ward Hill, Orphir. Although little environmental damage resulted, it is evident that peat slides can and do occur in Orkney, with risk of impact upon ecosystems.
Drainage conditions and topography have been important considerations for the design of the Hammars Hill project. The sites of the turbines and the switchgear house have been chosen to have none of the characteristics of an area at risk of peat slide and there is considered to be an insignificant risk of any movement of superficial deposits on any part of the site. As only shallow peat deposits occur on the proposed turbine sites it is considered that ecological damage caused by their disturbance shall be minimal..
4.5 Carbon emissions during construction
The maximum volume of topsoil that could be disturbed is approximately 1600 m3, consisting of the access track and hard standing area, a total area of 8000 m2 at an average depth of 0.2m. Assuming that the soils in this area have 0.069 tonnes of carbon per cubic metre of soil
Chapman et al, the carbon content of the soil is estimated to be 110T. The carbon emission factor of grid electricity is 0.117 T/MWh and assuming a mean windspeed of 9.6m/s, five 900kW wind turbines in this area will produce an annual energy yield of around 18,000 MWh at a capacity factor of 45%. An average production of 50 MWh per day, giving a positive carbon balance of 5.8 T per day; 19 days of generation are required to compensate for the potential carbon released from the topsoil. It should be noted that the construction process will retain the integrity of the peat systems, and all topsoil will be reused in other parts of the farm to avoid the release of carbon.
It is recognised that concrete production results in the emission of CO2 from both the energy required during manufacture and from the calcining of limestone when producing cement. A cubic metre of concrete is made from 2T of aggregate and 450kg of cement and the project will require approximately 500m3 of concrete. 500m3 of concrete requires 225T of cement, and assuming 0.75T of CO2 per tonne for the energy requirement, and 0.5T of CO2 per tonne from limestone calcining, IPCC Working Group II, p661, the total CO2 emissions during concrete
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manufacture for the project is 280T. Using a CO2 avoidance factor of 0.49T CO2/MWh from an annual production of 18,000 MWh, the wind turbines provides a positive CO2 balance of 24T per day; 12 days of generation are required to compensate for the carbon dioxide released during concrete manufacture
There will be an increase in traffic levels during foundation and access track construction, and during mobilisation and installation of the turbines; 20 loads of turbine components will be transported to site, with up to 5 loads of components for a 350T telescopic crane. The estimated volume of stone required for all construction is 2500m3, and although stone will be produced during the levelling and excavation of the road and foundations, this represents the maximum volume that could be delivered to site. Allowing for large vehicles with 48T per load, approximately 100 loads will be required for all construction work. It is expected that a large proportion of this stone will be glacial till and fractured rock recovered during foundation and road excavation, with the remainder coming from nearby quarries.
4.6 Pollution risk during construction and maintenance
The construction activities during mobilisation and installation of the turbines represent the greatest potential for pollution. This may be through operational discharges or as the result of an unplanned or accidental event. Given the nature of the agricultural land surrounding the site, and the location of Woodwick burn, measures have been identified to protect against the release of any material with the potential to leach into the soil or water courses. The construction of the access track leading from the valley of the farm to the hilltop ridge has the most significant risk of pollution, due to the use of concrete for this part of the track. There has been an initial consultation with SEPA, along with a site visit, and their guidance has been used to help design the track layout. All temporary welfare facilities will be located away from the site, within Savisgarth Farm during the construction of the roads and hardstanding. There will not be any pollution discharges during the construction process, with details of pollution prevention and mitigation measures included in part 5, below.
4.7 Potential disturbance from noise Section 6 of this report is the Environmental Health Impact Assessment, which addresses potential noise effects, along with shadow throw and flicker impact. Noise is generated by the turbine blades passing through the air as the hub rotates, with minimal mechanical noise due to the characteristics of the chosen turbine. Noise in the environment is measured in decibels using the dB(A) scale which includes a correction for the response of the human ear to noises with different frequency content. A 1dB change in noise level is just perceptible, a 3dB
OSE/2825 52 Orkney Sustainable Energy Hammars Hill February 2008 change in noise level is clearly perceptible and a 10dB change in noise level is heard as a doubling or halving of the perceived level. The noise levels from the Enercon E44 turbines is 100 dB(A) at a windspeed of 8ms-1. This value decreases with distance from the turbine and with atmospheric absorption. Figure 4.6 shows the predicted impact at the neighbours to the development along with other indicative noise levels.
Source/Activity Indicative noise level dB (A)
Threshold of hearing 0
Rural night-time background 20-40
Hammars Hill turbines 22.6 – 35.9
Quiet bedroom 35
Busy road at 5km 35-45
Car at 65 km/h at 100m 55
Busy general office 60
Conversation 60
Truck at 50kmh at 100m 65
City traffic 90
Pneumatic drill at 7m 95
Jet aircraft at 250m 105
Threshold of pain 140
Figure 4.6 – Indicative noise levels in the environment
The Planning Advice Note on Renewable Energy Technologies, PAN 45 provides information on noise from wind turbine. Paragraph 65 states: "Well designed wind turbines are generally quiet in operation". The document goes on to discuss the sources of noise and the effects of increasing wind speed on wind turbine noise and background noise. It notes that the report “The Assessment and Rating of Noise from Wind Farms” ETSU-R-97, describes a framework for the measurement of wind farm noise and gives indicative noise levels thought to offer a reasonable degree of protection to project neighbours, without placing unreasonable restrictions on wind farm development or adding unduly to the costs and administrative burdens on wind farm developers or planning authorities.
The impact of noise from the wind turbines is not adversely significant. The noise levels from the Enercon E44 is variable, ranging from 100 dB(A) to 104 dB(A). This value decreases with distance from the turbine, with atmospheric absorption and from ground conditions and barrier attenuation. When considering the impact from a windfarm, the noise
OSE/2825 53 Orkney Sustainable Energy Hammars Hill February 2008 levels from the individual wind turbines that can be seen from the neighbour must be combined, and the calculations have included all the wind turbines.
The turbines are located 580m to 830m from the nearest neighbour to the east and 950m to 1500m from the nearest neighbour to the north. Desk-top analysis has been conducted to assess the potential impact, using a geometric spreading and atmospheric absorption model. The properties have been chosen to represent the impact upon the different parts of the community. Five properties have been assessed, including Savisgarth, the project landowners. The open nature of the countryside, the high moorland nature of the site along with the long distances between the turbines and neighbours are important considerations. The spacing between turbines and neighbours is large, and as a consequence cumulative noise impact is low. The spreadsheet used to calculate impact takes into account geometric divergence of noise, along with atmospheric absorption, to give a theoretical calculation of sound levels at neighbours; Section 6 of the report contains the full analysis and assessments. With the neighbours predicted to have sound levels between of 22.6 and 35.9 dB(A), noise emissions achieve the recommendations of the simplified ETSU-R-97 assessment and these sound levels are well below the permitted amenity hours and night time noise limits, and are below the 45dB(A) limit recommended for neighbours with a financial involvement.
4.8 Potential disturbance from shadow flicker
Under certain combinations of geographical position, time of day and time of year, the sun may pass behind the rotor and cast a shadow over neighbouring properties. When the wind turbine blades rotate the shadow appears to flick on and off, creating an effect known as shadow flicker, and is noticeable only in buildings when viewed through narrow window openings. For the properties in the Hammars Hill area this would normally occur at midday in the winter months when the sun is at low elevations..
Planning advice note PAN45 recommends 10 rotor diameter separation between the wind turbine and the nearby dwellings to avoid shadow nuisance, and the Hammars Hill project achieves this recommendation by a large margin; 10 rotor diameters is 440m and all turbines are 440m or more from neighbours. Nevertheless the potential for shadow effects was checked for a selection of neighbouring properties around the site using the WINDFARM software tool, regardless of the distance, with full results and graphs shown in Section 6. It has been presumed that windows face directly on towards the turbine to produce worst case examples.
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Analysis of the risk from shadow flicker indicates that the impact of the wind energy project upon neighbouring properties is not significant. The nearest community is Evie Village, and is more than 2km from the wind turbines, and for the neighbours located nearer to the site, none are within the recommended 10 rotor diameter clearance distance of 440m. Due to the relative geometry of the site only Savisgarth and Greystone to the north-west of the site have any degree of impact, with the maximum theoretical impact over the whole year of 26 hours. It is noted that in the case of that particular property the impact will be extremely insignificant as the turbines are 950m-1500m from the house, far greater than the 10 rotor diameters, or 440m recommended in PAN45.
Should the extremely marginal nature of this impact still be felt to be unacceptable, the turbine can be switched off automatically during the brief periods when a shadow could occur on sunny days. This shadow impact control module works independently of the turbine controller, and uses a photocell to measure sunlight. By knowing the exact times when a shadow could reach a nearby property, this control module prevents operation for around 12 minutes on the days in midwinter when shadows could occur.
Figure 4.7 – Neighbouring properties assessed for noise and potential shadow impact
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4.9 Potential radio-communications interference
When a wind turbine is positioned near to a radar, radio, television, or microwave transmitter system, it may reflect some of the electromagnetic radiation in such a way that the reflected wave interferes with the original signal as it arrives at the receiver; this can cause the received signal to become distorted. The extent of any electromagnetic interference caused by a wind turbine depends mainly on the blade materials and the surface shape of the tower. Electromagnetic interference may also occur if a wind turbine is close to a radio communications service. OFCOM, the Radio-communications Agency indicated that there are three commercial microwave links traversing this part of Orkney, routed from the Keelylang and Wideford transmitters to receivers at Milldoe and Burgar Hill. Each link should have a 200m wide exclusion corridor to avoid interference, and at the nearest point the clearance between Milldoe and the Hammars Hill turbines is around 1.5km.
There is a recognised risk of interference to analogue television transmissions by wind turbines; where reception is generally poor, the metal towers and reflective blade surfaces can result in ‘ghosting’ when the reflected signal is read by television receivers. Should television reception be found to be poor in areas around the site, and should interference occur, then there are proven improvement techniques, principally the use of digital or satellite television services.
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5 Environmental management and mitigation
This report has described a proposal to construct a small wind farm at Savisgarth farm, Evie in Orkney, together with an assessment of the related activities. This part of the report describes the proposed environmental practices and any necessary mitigation measures.
5.1 Visual impact mitigation
The planning advice note on Renewable Energy Technologies, PAN 45, states “Turbines in wind farms are likely to be tall, frequently located in open land, and therefore likely to be highly visible” and “It will normally be unrealistic to seek to conceal them. Developers should seek to ensure that through good siting and design, landscape and visual impacts are limited and appropriate to the location”, and “Although wind farms may be complex, they should not appear confusing in relation to the character of the landscape. Ideally they should be separate from surrounding features to create a simple image”. It is believed that Hammars Hill achieves these recommendations to a high standard.
Hammars Hill wind energy project falls within Zone 1 of Scottish Natural Heritage’s “Strategic Locational Guidance for Onshore Windfarms in Respect of Natural Heritage”, defined as the zone of least sensitivity. The design process determined that a relatively small turbine would be appropriate for the moorland landscape; the turbine finally chosen for the development has a 45m tower and a 22m blade, smaller than any other turbine built in Orkney. The turbines have also been brought together in a compact linear layout, and with only 200m between machines, a relatively small part of the landscape has been used for the development. The project is a good fit to the landscape, the turbines are entirely appropriate for the setting, and it should also be considered that the shape of the Enercon nacelle was designed by Lord Foster, and is both aesthetically pleasing and dynamic in form.
The project access track is an extension of the existing access to Savisgarth, and for the route to the hilltop, the track will be constructed by pouring a thin layer of concrete directly onto a sloping stone base. This concrete road will be dyed brown to merge into the existing peat and heather background. The turbines themselves have a unique green-banded tower base, which provides visual connection between the turbines and the surrounding landscape. This is particularly relevant for the most significant view, that from the village of Evie., and all site cabling is to be positioned underground. The only additional infrastructure is a small building, located at some distance from the turbine site. It is therefore felt that the visual impact of the Hammars Hill project has been well managed and is not adversely significant.
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5.2 Ecological impact assessment and mitigation
Impact assessment and mitigation – vegetation and Otters In line with the most recent IEEM guidelines, the final assessment of impacts classes them as either significant or insignificant on the affected population, at the relevant geographical scale. The significant impacts identified, and proposed measures to avoid or mitigate for these, are summarised in Table E below.
This loss of blanket bog would be regarded as locally significant at the West Mainland scale. The loss of trackside grassland, and the potential disturbance to drainage in the base-rich flushes and flushed heath along the cable route, might be of very local significance within the immediate area around the development site. All other vegetation impacts are on an insignificant scale.
The mitigation/compensation measures proposed are an overall reduction in grazing pressure on the hillside (perhaps including the fencing-off of the hilltop), and the extension of ungrazed grassland along the Woodwick Burn. These would lead to an improvement in the condition of the blanket bog and grassland vegetation. However, the residual impact on blanket bog would still be locally significant, whereas there should be a net positive effect on grasslands. It is hoped to avoid significant drainage impacts on flushes by appropriate construction methods to minimise the compaction of soil and to minimise the drainage effect of the cable trench. An important part of this would be to undertake cable-laying in dry conditions, preferably during the summer when the ground would also be as dry as possible.
After such mitigation and compensatory measures, the only significant residual impact on vegetation, individually or combined, at Hammars Hill would be the locally significant loss of blanket bog. It is not expected that Otters would be impacted by the development in any way.
Table E. Summary of potential significant impacts and residual impacts. Impact Nature of impact: Valued receptor Geographical scale at Avoidance Scale of potentially impacted which impact /Mitigation significance of to to to (1) (1) per un-
likel significantly considered significant proposed residual impact y (1) term wide Very Very Very local Shor Blanket bog W Mainland YES W Mainland Habitat loss 5 2 5 Trackside verges Site only YES Positive Base-rich flushes Site only YES Site only? Habitat disruption 5 1 3 Flushed wet heath Site only YES Site only? Construction Hen Harrier SSSI YES Nil disturbance 2 3 4 Short-eared Owl Site only YES Nil (breeding) Golden Plover Site only YES Nil Construction disturbance (non- 2 3 4 None breeding) Displacement 4 2 2 Golden Plover W Mainland NO W Mainland (breeding birds) Displacement (roosting & 4 2 2 None foraging birds) Red-throated Diver Site only NO Site only Collision fatalities 4 1 2 Kestrel Site only NO Site only
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Impact assessment and mitigation – birds
The most important potential significant impacts on birds relate to disturbance during construction (should it take place during the breeding and pre-breeding season from March onwards); the significance level would be up to that of the SSSI for harriers. During the operational phase, the displacement of one pair of Golden Plovers would be regarded as locally significant, but the displacement of a few pairs of the commoner waders would be insignificant. Significant construction disturbance impacts on breeding birds is readily avoided by timing works to be outside of specific key periods, and for this reason, the construction at Hammars Hill would be planned as follows: a. Cable-laying – any time spring/summer. It is particularly crucial to do this work in dry conditions, to prevent the cable route from becoming a trackway for water. Because the cable route is at the eastern end of the hill, there would be no impact on important breeding birds. b. Widening of existing farm track up from the A966 to Neigarth – any time spring/summer. The widening required would be little more than a metre at any point – this stretch of the route is located away from the hillsides and moorland areas and is already a focus for agricultural activities and vehicle movements. c. Digging out the first 250m along the line of an existing ditch (and concrete laying onto bedrock) – from the beginning of June. To allow for the pre-laying period in Hen Harriers to be completed, during which they are considered to be most affected by shortage of food; disturbance to foraging harriers at this key time will therefore be avoided. Operations would require only a digger and a dumper truck and would be partially obscured by the banks of the ditch and spoil mounds – at such a scale, they would not be expected to disrupt breeding owls or Golden Plovers higher up the slopes. d. Digging the main part of the new track and the turbine hardstandings– from the beginning of July. To allow for hatching of the owl eggs from the nearest territory, at about 300m, prior to commencement (the birds would not be expected to be prone to desertion once they had young to feed). Any breeding Golden Plovers on the hilltop would also be expected to have mobile young by then, if they had not already fledged.
Displacement of Golden Plovers during the operational phase cannot be avoided or mitigated. An increase in background mortality of 1.3% to 2.6% for the adult divers on the SPA (at 97.5% and 95% avoidance rates respectively) equates to a reduction in the survival rate of 0.25% to 0.50%. Such a decrease in survival is unlikely to be significant for the SPA and would not be expected to adversely affect its integrity in terms of Red-throated Divers. It would however be very locally significant on two pairs closest to the development site.
One of the highest levels of calculated risk (in relative terms) is to the Peregrine – however a lower, effective increase of 1.79% in mortality for first year Peregrines in the Orkney population has been calculated, which equates to a reduction in survival of 3.32%. Since the
OSE/2825 59 Orkney Sustainable Energy Hammars Hill February 2008 populations of long-lived, slowly reproducing birds, such as the Peregrine, are much more influenced by adult survival than first year survival, this would probably not represent a significant impact to Peregrines in Orkney.
Kestrels are also considered to be at some risk from collision, and this would probably be very locally significant for the one or two pairs closest to the development.
In addition to the avoidance/mitigation measures suggested to offset predicted development impacts, it is also proposed to promote a net environmental gain by voluntarily continuing certain of the Rural Stewardship and Hen Harrier Scheme operations when these schemes come to an end. This would leave the currently ungrazed areas under the Hen Harrier Scheme in an unmanaged state; the hedges planted under the RSS would remain, and the unharvested bird crop would be continued. The bird crop would be moved further away from the turbine positions down to the fields near Savisgarth. Here it should be slightly more sheltered and would be close to better cover for feeding birds, so increasing its attractiveness.
In summary, after the measures proposed, there is a relatively low likelihood of significant, but localised, impacts on Golden Plovers (due to displacement from the operational turbines), and on Red-throated Divers and Kestrels (from collision risk). There should however be a net gain for seed-eating birds and foraging raptors.
Cumulative impacts on the SPA and SSSI
There are various other proposed wind energy projects in the West Mainland that do, or could potentially, affect the Orkney Mainland Moors SPA. Hammars Hill will not have any direct impact on the SPA e.g. in terms of habitat loss on the SPA, foraging displacement on the SPA or disturbance due to increased public access on to the SPA. These effects would only occur at Holodyke (near Dounby) where they have been assessed as insignificant; there would be no significant cumulative impact. There would be no predicted displacement of breeding SPA species at any of the likely development sites.
Significant cumulative impact on the SPA species might be a possibility due to collision fatalities, particularly on Red-throated Divers and Hen Harriers. The harrier populations to be considered are those of the SPA as a whole and, separately, the smaller numbers on the West Mainland Moorland SSSI, whereas all the SPA divers breed on the West Mainland Moorland SSSI. For Red-throated Divers the highest risk to the SPA population is already present at
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Burgar Hill (about 85% of the calculated risk). The five turbines at Hammars Hill, lying much further from the nearest breeding pairs, are predicted to pose up to 8% of the total risk.
The cumulative collision risk to Hen Harriers is calculated at one fatality every four years (97.5% avoidance) and one every ten years (99% avoidance). This equates to a proportional increase in annual mortality of about 0.7% to 1.7% for the SPA harriers (i.e. from the 19.6% background rate, up to 19.7–19.9%), and to a proportional increase in annual mortality of the SSSI population of about 1.4% to 3.6% (i.e. from 19.6% to 19.9–20.3%). Any increase in mortality would cover the whole year and would be spread across the population in terms of sex and age. It seems unlikely that such a small increase in mortality would be significant for the SPA population. By comparison, the collision risk found to be unacceptable on the SPA at Gruf Hill was one fatality every five years, but this was calculated on the summer months only (i.e. for the whole year the number of fatalities might have been doubled) and was thought to impact mainly on breeding males (whose loss would have a much wider effect on the population than that of a female or a juvenile). The SSSI figures are relatively higher, but represent a reduction in survival of just 0.35–0.88%. It is unlikely that such figures would represent a significant impact on the SSSI population.
Cumulative impacts – non-SPA/SSSI
The cumulative collision risk to non-SPA species may not be significant for the sites currently proposed or approved. However, given the poor health of the Peregrine population in Orkney, cumulative significance is perhaps more likely for this than any other species. Adult fatalities will have more of an impact on the population numbers, and this is more likely to occur at sites near eyries. The risk to adults at Hammars Hill is very low, with one fatality calculated every 48 years at 95% avoidance.
Kestrels are likely to be at less risk at all of the other existing, approved or proposed sites, so that there will be no significant cumulative impact beyond the very local level around Hammars Hill.
Loss of semi-natural habitats on undesignated land would occur at three proposed or approved Mainland sites (Merranblo, Holodyke and Hammars Hill) and has already happened at Burgar Hill. The greatest loss is probably at Hammars Hill, where it is assessed to be locally significant at the West Mainland scale.
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5.3 Mitigation of potential impact upon archaeology
No indications of actual or potentially significant archaeological remains have been identified within and immediately around the development area. Therefore no mitigation or other concern is registered for: • the 5 turbine locations; • the on-site access track route; • on-site cabling; • any on-site sourcing of stone or other construction material, although this is not a major element of the design policy; • a works compound; • any off-site road modifications to allow turbine and other construction transport.
Some minor archaeological mitigation and/or works monitoring may be appropriate for the final stretch of the interconnector route close to the National Grid connection and the associated switchgear building, both of which would occur in the vicinity of HY 392/230. This area has a relic 19thC or earlier landscape which could be affected by these works.
A 25m exclusion zone is proposed for the pair of possible prehistoric tumuli at HY 38969/22755 and 38965/22737 which lie some way east of the upper portion of the cable route; the project shall fully avoid these possible tumuli, and in any event they could only be affected by plant transit rather than direct construction activity.
A potentially significant aspect for this development is the visual impact it would have on a number of monuments in the custodianship of Historic Scotland as Properties In Care. While there will be some degree of visual impact for these sites, the assessment regards them as insufficient to cause significant concern or to prevent the development.
5.4 Groundwater Management and Pollution Avoidance
The construction of the access track and the areas of hardstanding have the highest likelihood of pollution, and SEPA’s Pollution Prevention Guidelines PPG1, PPG5, PPG6, PPG8 and PPG21 have been adopted by the project: www.sepa.org.uk/guidance/ppg/. To combat the potential risk of run-off from these areas, it is proposed that some of the mechanisms used to construct Sustainable Urban Drainage systems be adopted, using methodologies recommended in the Control of Water Pollution guidelines CIRIA C532, C649, C648 and CIRIA C697 the SuDS Manual.
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The construction of section 1 of the access track and the foundations of the turbines involve pouring fresh concrete, however it is proposed that all concrete be brought onto site ready mixed to minimise the risk of spills. The nearest watercourse is around 500m from the nearest turbine location, reducing the risk of pollution run-off. The following priorities have been identified in terms of groundwater management:
1. Protection of the Woodwick Burn 2. Prevention of peat and mud slides 3. Avoidance of erosion
Groundworks shall be generally be carried out in the drier months of the year. This will minimise the volume of water that will be mixed with soils being handled and also reduce the amount of water liberated from the ground during excavations. The draft Roads and Foundation Constriction Method Statement, part 2.9 of this report, above, provides a summary the proposed groundwater control mechanisms.
To minimise risk of pollution from oils and fuels during project construction, all work will be to COSHH regulations and any machinery, equipment or construction material will be located on areas of hardstanding away from water courses, within Neigarth:
• Fuel storage will be in double-skinned tanks at the Neigarth farmyard • No refuelling will take place within 50m of a watercourse • Plant will be regularly inspected for leaks and spillages • All plant will carry absorbent pad spill kits • Any static plant at the substation compound will be bunded or fitted with a drip tray • Self-contained Portaloos and facilities will be located on the site hardstanding.
5.5 Mitigation of noise disturbance
The site has been designed to ensure that the turbines are 580m or more from the nearest houses; at this distance the noise from the wind turbines will be reduced to the national levels recommended by PAN45 and ETSU-R-97. Turbine noise levels are attenuated due to geometric divergence, atmospheric absorption, and ground effects, and for near neighbours the hill itself is a significant barrier to noise effects; the nearest neighbours do not see all of the wind turbines. The project will use gearless variable speed wind turbines and the operational characteristics of the machines will be adjusted to ensure that noise levels remain at 35dB LA90 or less at all neighbours, ensuring that there is no significant loss of amenity to the properties that surround the site.
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5.6 Mitigation of shadow flicker nuisance
The site has been designed to ensure that the wind turbines are ten rotor diameters or more from all neighbours; at this distance any shadow flicker nuisance will be minimal (PAN45). Moreover only one neighbour has any possibility of shadow effects as the sun is never in a position to create wind turbine shadows at the other properties, and that this neighbours is more than 1km away the nearest turbine. This distance is far greater than the 10 rotor diameters, or 440m recommended in PAN45; shadow effects are insignificant.
5.7 Construction and transportation impact mitigation
There will be construction noise during the road and foundation manufacture, mainly from lorries over a 3 to 5 month period. The community and authorities will be consulted about suitable times for lorry movement and a construction schedule will be published. Before any wind turbine components are transported to site, the Developers will consult with the Scottish Government, Orkney Islands Council Roads Department and the Police to ensure acceptability of the route to site. Existing public road culverts, bridges, verges and street furniture will be surveyed by the project developers in conjunction with the Roads Department. Road warning signs and lights will be located at all areas of road works and any items such as fence posts and road signs that have been temporarily removed will be re- erected following transportation.
5.8 Mitigation against television interference
The potential for interference to television systems cannot be predicted, but there is the possibility of interference to analogue receivers if reception in the area is generally poor. The interference created by wind turbines is very distinctive and readily identifiable; should interference occur, and is clearly shown to be due to the wind turbines, the owners of the affected property will be offered a digital or satellite television service. This mitigation mechanism has been demonstrated at the Burgar Hill windfarm west of Hammars Hill, and in any event the television analogue service for Orkney will be switched off in 2010.
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6 Conclusions
This study has described a project to install five wind turbines on moorland at Savisgarth, in the Evie parish of West Mainland Orkney. The environmental and social impacts of the project has been considered in detail, with emphasis on visual impact, impact upon habitats, potential disturbance to birds, archaeology impacts, pollution control and potential nuisance impact upon neighbours. A life-cycle analysis of the development has been provided, covering the location, the sustainability of the project, the type and size of wind turbine to be installed, and the installation, operations and eventual decommissioning of the site. The study has further addressed the environmental and socio-economic benefits of the project to Orkney.
The visual impact upon the landscape has been considered in detail and the project has evolved into a medium scale linear development, with overall turbine height of 67m. Although any wind energy project involving modern wind turbines will be seen from the surrounding area, the installation of wind turbines on this site would only have a high level of visual impact on the immediate surroundings, mainly the scattered housing at Hackland and the village of Evie. Over greater distances the moorland landscapes become more dominant and the wind turbines become subservient, with no impact whatsoever to the World Heritage site in the West Mainland of Orkney.
Impact upon the ecology of the area has been considered in detail and a fully encompassing ecological assessment has been completed. The general area for the development was selected to maximise distances to any ecologically sensitive species, and the turbines have been located on poorly drained peaty moorland; the overall potential impact upon habitats, mammals and bird species is not predicted to be adversely significant.
An extensive archaeology survey and impact assessment has been completed, with very little risk of direct impacts upon any historic sites, and only a marginal risk of impact upon the setting of historic monuments and Properties in Care.
The Hammars Hill Wind Energy Project has been designed to respect the environment, and to provide a commercially viable development, with very strong local economic benefits. The project is locally-owned and incorporates mechanisms to fully engage with the local community; the development is a privately funded local windfarm, providing significant financial returns to all members of the Orkney community wishing to participate in the project. The Hammars Hill project gives a positive message on the importance of renewable energy to Orkney, and demonstrates the significant economic benefits of local ownership.
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7 References and bibliography
BWEA (1998). Best Practice Guidelines for Wind Energy Developments. Website www.bwea.com/
Boardman, B et al. (1997) 2MtC: Two Million Tonnes of Carbon, Environmental Change Unit, University of Oxford.
Boyle, G (1996). Renewable Energy; Power for a Sustainable Future. Oxford University Press.
British Geological Survey (1955). One-Inch Geological Map of Scotland. Sheet 119 Drift edition.
The Carbon Trust. Guidelines on measuring carbon and CO2 emissions from electricity. http://www.thecarbontrust.co.uk/carbontrust/low_carbon_tech/dlct2_1_6.html
Chapman, S.J., Towers, W., Williams, B.L., Coull, M.C., Paterson, E. (2001) Review of the Contribution to Climate Change of Organic Soils Under Different Land Uses. Scottish Government Central Research Unit.
Defence and Civil Aviation Interests Working Group (2002). Wind Energy and Aviation Interests – Interim Guidelines. ETSU W/14/00626/REP
DTI Noise Working Group (1996). The Assessment and Rating of Noise from Projects. ETSU-R-97.
Scottish Planning Policy SPP6 (2007). Renewable Energy. Scottish Government Development Department. ISBN 0 1-84268-684-4
Planning Advice Note PAN 45 (2002). Renewable Energy Technologies. Scottish Government; ISBN 0 7559 0372 2
Planning Advice Note PAN 56 (1999). Planning and Noise. Scottish Government Development Department.
Planning Advice Note PAN 58 (1999). Environmental Impact Assessment. Scottish Government; ISBN 0 7480 8912 8
Planning Advice Note PAN 68 (2003). Design Statements. Scottish Government; ISBN 0 7559 0862 7
Planning Advice Note PAN 73 (2005). Rural Diversification. Scottish Government; ISBN 07559 44259
Scottish Natural Heritage. Guidelines on the Environmental Impact of Projects and Small Scale Hydroelectric Schemes. SNH Publications
Scottish Natural Heritage (1998). Orkney Landscape Character Assessment. SNH Publications
Scottish Planning Policy SPP15 (2005) Planning for Rural Development. Scottish Government Development Department.
SEPA pollution prevention guidelines http://www.sepa.org.uk/guidance/ppg/
SEPA recommendations on drainage systems in Scotland - Sustainable Urban Drainage Systems (SUDS). http://www.sepa.org.uk/publications/leaflets/suds/?lang=_e
Soil Survey of Scotland (1981). Soil, Land Use Capability – Orkney Mainland. The Macaulay Institute for Soil Research, Aberdeen.
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