who we are - ssen transmission · pdf fileorkney project public consultation november 2017 ...

Orkney Project Public Consultation November 2017

www.ssen-transmission.co.uk/projects/orkney

Who we are

WesternIsles

DounreayGills Bay

Orkney

Shetland

Spittal

Mybster

Lairg

Mossford

Skye

Beauly

Loch Buidhe(Bonar Bridge)

Moray Firth

Knocknagael

TomatinFort Augustus

Fort William

Dalmally

Kintyre

Arran

Hunterston

DennyKincardine

Perth

Aberdeen

Peterhead

Blackhillock

Kintore

WesternIsles

DounreayGills Bay

Orkney

Shetland

Spittal

Mybster

Lairg

Mossford

Skye

Beauly

Loch Buidhe(Bonar Bridge)

Moray Firth

Knocknagael

TomatinFort Augustus

Fort William

Dalmally

Kintyre

Arran

Hunterston

DennyKincardine

Perth

Aberdeen

Peterhead

Blackhillock

Kintore

Overview of Transmission projects

Existing infrastructure

Under construction

Potential development

Key

www.ssen-transmission.co.uk/projects

In total we maintain about 5,000km of overhead lines and underground cables – easily enough to stretch across the Atlantic from John O’Groats all the way to Boston in the USA.

Our network crosses some of the UK’s most challenging terrain – including circuits that are buried under the seabed, are located over 750m above sea level and up to 250km long.

The landscape and environment that contribute to the challenges we face also give the area a rich resource for renewable energy generation. There is a high demand to connect from new wind, hydro and marine generators which rely on Scottish and Southern Electricity Networks to provide a physical link between the new sources of power and electricity users. Scottish and Southern Electricity Networks is deliveringa major programme of investment to ensure that the network

is ready to meet the needs of our customers in the future.

Our responsibilitiesWe have a licence for the transmission of electricity in the north of Scotland and we are closely regulated by the energy regulator Ofgem.

Our licence stipulates that we must develop and maintain an efficient, co-ordinated and economical system ofelectricity transmission.

What is the difference betweenTransmission 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.

Overview of Transmission projects

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.

Existing network in Orkney



There is currently no transmission infrastructure on the Orkney Islands.The electricity network on Orkney is connected via two distribution subsea cables between Rackwick Bay on Hoy,and Murkle Bay near Thurso.

These cables were installed in 1982 and 1998 with a total import/export capacity of 40MW. Demand on the islands varies between 7MW in summer and 46MW in winter. The current connected embedded generation in Orkneyexceeds the capacity of the existing 33kV cables and no further generation can connect to the system at this time.

Why reinforcement is required

At present, the current level of contracted generation between National Grid (the system operator) and developers is for a minimum of 180MW of new generation by 2022.

To connect this level of generation, a transmission connection is needed between Orkney and the Scottish Mainland.

An alternative, innovative approach

To proceed with a transmission connection first requires regulatory approval from Ofgem, which in turn requires the contracted developers to financially commit to their projects. The current regulatory framework requires capacity to be allocated in chronological order based on respective developers contracted position.

Due to a number of factors over recent years, such as changes in government policy or the readiness and commercial viability of renewable energy projects across Orkney, it has not been possible to proceed with the transmission proposal through the current regulatory process.

To try and overcome this impasse and help Orkney realise its vast renewables potential, we are considering an alternative approach to allocate the necessary volume of capacity that is required to underpin the case for the proposed 180MW Phase 1 connection.

This approach would see capacity allocated on a ready to connect basis, whereby those developers who are ready to commit to their projects would be allocated capacity. This innovative approach, the first of its kind in GB, would first require approval from both the energy regulator, Ofgem, and the System Operator, National Grid.

A separate consultation on this proposed approach will be launched in early 2018.

Our proposed solution



To provide the most efficient and economical solution for the network we are proposing to provide a new connection from a central point within the Orkney Isles in order to maximise the opportunity for generators to connect to the transmission network.

The new link would provide an additional 180MW of capacity. The main elements of the projects are as follows:

• A new substation at Finstown;

• An underground cable linking Finstown substation to a cable landing site west of Stromness;

• A marine cable linking Mainland Orkney and Caithness;

• A new cable route between the Dounreay marine cable landing point and the new substation at Dounreay; and

• Construction of a new substation at Dounreay.

Finstown Substation selecting a site

Finstown was identified as a central area for a new substation which would enable the connection of renewable generation projects.

A preliminary search for substation sites in the vicinity of Finstown was made based on a desktop assessment and site visits by members of the team. Four sites of 250 x 250m were selected, which would allow for the substation development and a construction laydown area. Technical engineering requirements, environmental and financial considerationswere all considered in balance to arrive at the short-listed sites in the vicinity of Finstown.

We are proposing to construct a 220/132kV substation using both Gas Insulated Switchgear (GIS) and Air Insulated Switchgear (AIS). All of the substation equipment would be housed indoors to protect against corrosion.



Finstown Substation

The same basic design was used to allow for the sites to be assessed.

Environmental considerations included the following: Visual Amenity, Landscape Character, Ecology (habitats and protected species) Ornithology, Archaeology and Cultural Heritage, Recreation and Access, Geology and Soils, Watercourses and hydrology

Technical criteria included aspects of the development including health and safety during construction and operation, construction timescales, maintenance requirements and potential for future development and connections.

Based on these criteria, the sites were ranked in order of preference, with Site FT2 being identified as the preferred site option, and Site FT1 as the second preferred option. Site FT4 was ranked third, and Site FT3 was ranked fourth.

Site FT2 has therefore been selected as the preferred site option on the basis of technical, environmental and cost criteria.

Renewable generators connecting to Finstown Substation

Connections will be required between the substation at Finstown and renewable generators. These connections are expected to be primarily by overhead line, with marine cabling between Mainland Orkney, Hoy and South Ronaldsay.

During our consultation events earlier this year, we presented the various types of technology that we could use for the overhead line connections.

These included steel lattice towers, composite towers, single circuit wood poles and twin circuit wood poles.

The comments received during our consultations are used to influence how we progress with our projects.

Therefore based on the feedback received, we will not be considering steel lattice towers going forward.

Dounreay Substation

We are proposing to construct a new 275/220kV substation using Gas Insulated Switchgear (GIS) at Dounreay.

All substation equipment will be housed indoors to protect against corrosion.

A 275kV cable will connect the new Dounreay substation back to the existing Dounreay substation.

We carried out an assessment on the four proposed substation sites against technical, environmental and cost considerations.



Underground cable

We are proposing to use an underground cable to link our proposed Finstown substation to a cable landing site at Warebeth/Billia Croo.

The process for selecting any cable route is based on identifying the most direct and shortest route possible. From initial desktop studies a proposed route was identified within a 500m corridor. The main basis of criteria for route selection is to establish the technical, economic aspects, environmental factors, constructability and build duration.

Outputs from an initial site survey allowed the team to plot a cable route alignment giving the most direct route option from the landfall points to Finstown. Soil maps were also consulted to try and avoid any areas of peat, which can affect the thermal properties of cables. Peat also presents challenges for environmental impact.

An initial route up to 500m in width has been identified. Ecology and archaeology desk studies and surveys have taken place in October and November 2017 to ensure that the final route has the least possible impact on the environment and cultural heritage.

Ground investigations (boreholes and trial pits) are also planned for early 2018 at the potential landfalls at Warebeth and Billia Croo, as well as along the proposed cable route. This information will inform cable design and routing, as well as construction methodology.

Discussions with landowners will also take place prior to finalising the cable route.

Feedback from stakeholders and membersof the public will also inform the final route.

The proposed route avoids much of the built up area and infrastructure near to Stromness and the outlying settlements, avoiding much of the road network and other buried utility providers. This reduces impact on construction timescale duration, and therefore, reduces disruption to traffic, local communities, emergency services and tourism on the island.

The final cable alignment will be 30-50mwide to allow for construction and installation of the cable, including the cable trench, an access road and drainage.



A marine cable linking Mainland Orkney and Caithness

The final route between the preferred landfall at Warebeth/Billia Croo and Dounreay was selected on the basis that:

• It achieves maximum potential for cable burial• It avoids major seabed hazards (e.g. sand wave fields, areas of exposed bedrock)• It requires a limited number of cable crossings

• Potential impacts on marine wildlife are limited• Potential interactions with other sea users (fisheries, shipping and navigation) are also minimised

Next Steps1. Survey of preferred cable route• Survey using multibeam echosounders, sidescan sonar, video and grabs

• Survey will identify seabed type, sediments depth, wrecks, Priority Marine Features (PMFs) and other sensitive habitats

• Route will be modified to avoid impact to protected features, UXO and wrecks as far as possible

• Objective is to optimise cable burial to improve security

2. Further consultation• Further stakeholder consultation will be undertaken in order to optimise routing

3. Route finalisation• Following survey, and stakeholder consultation, a study to understand the potential effects of the cable on the environment and other marine users will be undertaken. Following this research our finalised proposed Route Position List (RPL) will be drafted.

4. Consent application• Pre-application consultation will be undertaken in 2018

• An application will be submitted to Marine Scotland in 2018.



Project timeline

The chart below shows the main stages of the development process and the opportunities there will be for members of the public to give feedback as project site design is refined.

Public consultation events

• Routing of marine cable connections and overhead line technology


• Final marine cable option;

• Detailed design of onshore cable routes; and

• Detailed substation designs.

Submission of consent applications

• Substation planning applications

• Marine consent applications

• Any other necessary consents

Commissioning (project energised)


• Preferred marine cable route between Orkney and Caithness;

• Preferred onshore cable routes; and

• Preferred substation locations at Finstown

Formal consent consultation events

• Preparation of marine consent application;

• Confirm permitted development rights/ prepare consent applications for onshore cables; and

• Preparation of substation planning applications.

Construction to commence

Feb/Mar2017

Spring/Summer

2018

Dec2018

2022

Nov2017

Late2018

2020

All dates are indicative at this stage.



Feedback

We understand and recognise the value of the feedback provided by members of the public during all engagements and consultations. Without this valuable feedback, the project development team would be unable to progress projects and reach a balanced proposal.

We are keen to receive your views and comments in regards to the following questions:

• Have we been clear in explaining the need for the project? • Do you agree with our approach for generators to connect on a ‘ready to connect’ basis? • Do you agree with our proposed substation location at Finstown? • Do you agree with our proposed cable route? • Do you with our proposed subsea cable landing points and routes?

Additonal information

Information will also be made available via the project webpage and social media channels:

Project Website:www.ssen-transmission.co.uk/projects/orkney

Follow us on Twitter:@ssencommunity

Follow us on Facebook:@ssencommunity

Community Liaison ManagerLesley Dow

[email protected]

07876 837 490

Lesley DowScottish and SouthernElectricity Networks,Inveralmond House, 200 Dunkeld Road,Perth, PH1 3AQ

Comments

Your views and comments can be provided to the project team by completing a feedback form or by writing to Lesley Dow, Community Liaison Manager.

We will be seeking feedback from members of the public and Statutory Bodies until 16:00, Friday 5 January 2018.

All received feedback will be assessed and the proposed options adapted where necessary.

who we are - ssen transmission · pdf fileorkney project public consultation november 2017 ...

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