Fort Augustus - Skye Project Public Consultation November 2017
Total Page:16
File Type:pdf, Size:1020Kb
Fortwww.ssen-transmission.co.uk/projects/fort-augustus-skye Augustus - Skye Project Public Consultation November 2017 Fort Augustus - Skye Project Public Consultation November 2017 02 www.ssen-transmission.co.uk/projects/fort-augustus-skye www.ssen-transmission.co.uk/projects/fort-augustus-skye Who we are We are Scottish and Southern Electricity Networks, operating under licence as Scottish Hydro Electric Transmission Plc for the transmission of electricity in the north of Scotland. What is the difference between Transmission and Distribution? Electricity Transmission is the transportation of electricity from generating plants to where it is required at centres of demand. The Electricity Transmission network, or grid, transports electricity at very high voltages through overhead wires, underground cables and subsea cables. The transmission network connects large scale generation, primarily renewables, to central and southern Scotland and the rest of Great Britain. It also helps secure supply by providing reliable connection to the wider network of generation plans. The Electricity Distribution network is connected into the Transmission network but the voltage is lowered by transformers at electricity substations, and the power is then distributed to homes and businesses through overhead lines or underground cables. OverviewOverview ofof TransmissionTransmission projects projects In total we maintain about 5,000km of overhead lines and Shetland Key underground cables – easily enough to stretch across the Orkney Existing infrastructure Atlantic from John O’Groats all the way to Boston in the USA. Under construction Potential development Our network crosses some of the UK’s most challenging terrain Gills Bay – including circuits that are buried under the seabed, are located Dounreay over 750m above sea level and up to 250km long. Spittal Mybster The landscape and environment that contribute to the challenges we face also give the area a rich resource for renewable energy Lairg Western Loch Buidhe generation. There is a high demand to connect from new Isles (Bonar Bridge) wind, hydro and marine generators which rely on Scottish and Mossford Moray Firth Southern Electricity Networks to provide a physical link between Beauly Knocknagael Blackhillock Peterhead the new sources of power and electricity users. Scottish and Skye Kintore Southern Electricity Networks is delivering a major programme Tomatin Fort Augustus of investment to ensure that the network is ready to meet the Aberdeen needs of our customers in the future. Fort William Our responsibilities Dalmally Perth We have a licence for the transmission of electricity in the north of Scotland and we are closely regulated by the energy Kincardine regulator Ofgem. Denny Kintyre Our licence stipulates that we must develop and maintain Hunterston an efficient, co-ordinated and economical system of electricity transmission. Arran 03 Fort Augustus - Skye Project Public Consultation November 2017 www.ssen-transmission.co.uk/projects Fort Augustus - Skye Project Public Consultation November 2017 Project Overview and Update Since our public consultation events in September 2016 we have continued to develop a project which will provide an increase of electrical capacity for the Isle of Skye. An additional 132kV overhead line to Skye is required to • Dismantle and remove the existing 132kV overhead enable the connection of new generation located in the wood pole line connecting Broadford and Dunvegan north of the island. This will also improve the resilience of substations. the transmission network between Fort Augustus and Skye. In addition to our project there will be new equipment The main elements of the project are as follows: installed at the Edinbane wind farm to facilitate the connection of the proposed new Glen Ullinish wind farm. • Construction of an additional, new 132kV overhead line using a double trident H wood pole from the At the Broadford substation an additional transformer will existing Fort Augustus substation to the existing be installed to cater for additional local demand such as Broadford substation. the proposed Marine Harvest facility at Kyleakin. • Construction of a replacement, higher capacity, Since we held our public consultation events in 132kV overhead line using a double trident H wood pole September 2016 we have been developing an initial between the existing Broadford substation and the design of a 132kV overhead line alignment. We now existing Dunvegan substation have a preferred alignment and are now seeking your feedback and comments. Legend Preferred Alignment Existing 132kV OHL Existing 275kV OHL Map of overall route 04 www.ssen-transmission.co.uk/projects/fort-augustus-skye www.ssen-transmission.co.uk/projects/fort-augustus-skye Project Timeline The chart shows the main stages of the development process and the opportunities where members of the public can provide comments or feedback in regards to proposals. Please note that all future dates are indicative at this stage. Early 2016 Initial consultation and options assessment Spring 2016 Consultations with key statutory bodies Technology confirmed and route selection study started • Scottish National Heritage, • The Highland Council, • Proposed technology and overhead line corridor • Historic Environment Scotland and (wide area between connection points) identified • Scottish Environment Protection Agency and further environmental studies undertaken within the defined corridor. has been undertaken to seek feedback on the project • Route options identified, options appraisal undertaken assessment methodologies. Engineering and high level and preferred route identified. environmental studies have also been carried out on the technology and corridor options. Sep Autumn 2016 2016 - Public consultation Summer 2017 Further environmental studies, initial overhead line • Consultation with statutory, non-statutory bodies design and alignment selection progressed and communities on initial project proposals. Document detailing scope of consultation published. • Review all feedback and publish the Report • Consultation Document presenting the preferred on Consultation. route published. • Confirm the proposed route. • Undertake further environmental studies and initial engineering design to identify the preferred alignment for the overhead line. • Confirm the preferred alignment for the overhead line. Summer • Report on Consultation for the Route published. 2017 - Late 2017 Consultation on preferred alignment selection Late 2017 - • Undertake consultation on the preferred alignment for Early the overhead line and hold further public consultations 2019 • Publish Consultation Document detailing the Consent application & contract tendering preferred alignment. • Confirm the proposed overhead line alignment and publish the Report on Consultation for the alignment stage. • Progress Environmental Impact Assessment (EIA) and determine the scope of the EIA with the statutory bodies. • Negotiations with landowners. • Preparation and submission of Section 37 consent application. • Contract tendering and procurement detailed design. Early 2020 - 2022 Construction and commissioning 05 Fort Augustus - Skye Project Public Consultation November 2017 Fort Augustus - Skye Project Public Consultation November 2017 Existing Infrastructure The existing 132kV overhead line which connects Fort Augustus and Skye consists of three distinct sections, which were constructed at different times over the past 65 years in response to changing needs. These include: • Fort Augustus Substation – Skye Tee – Quoich – steel lattice towers designed to carry a single circuit (three conductors) • Quoich to Broadford – steel lattice towers designed to carry two circuits, presently strung with a single circuit • Broadford to Dunvegan – trident wood pole designed to carry a single circuit Construction of an overhead wood pole line A typical H pole installation generally requires foundations of approximately 2.5 metres by 3.0 metres and to a depth of around 2.0 metres. To minimise construction impact and the requirement for access tracks helicopters are used wherever possible to help deliver the materials to the site. The picture adjacent shows a typical helicopter delivery of the steel work used on the top of a pole and the baulk timbers used in the foundation at the base of each structure. Helicopters are also used to assist with the stringing of the conductors. Construction of an overhead steel lattice tower line Tower position access utilises various methods including aluminium matting, rubber matting but typically stones track for accessing tower locations. Other methods can be utilised including helicopters for flying materials into very inaccessible/heavily constrained areas. Tower foundations are generally concrete pad and column type. Holes are first excavated and shored up before the reinforcement is placed and the concrete poured in. The areas are then backfilled and reinstated, leaving only the top of the column and stub visible. Piled foundations may be required where severe ground conditions are present. Floating pad foundations are utilised in areas with very high water tables. Towers are installed in pre constructed sections generally by todays Health and Safety standards utilising cranes. Towers are then wired in sections from predetermined tension towers utilising tension stringing methodology. 06 www.ssen-transmission.co.uk/projects/fort-augustus-skye www.ssen-transmission.co.uk/projects/fort-augustus-skye Alignment Process and