Scottish and Southern Energy Power Distribution Submarine electricity cables consultation
Open door events were held: 9 th September 2015 Stornoway Oban 15 th September 2015 16 th September 2015 Campbeltown 28 th September 2015 Aberdeen 29 th September 2015 Kirkwall 1 st October 2015 Lerwick
Content 1. Background 2. What's changed? 3. Key stakeholders 4. Why are we consulting? 5. What's happened so far & project timeline 6. Installation methods 7. The Cost Benefit Analysis (CBA) method 8. Impact categories 9. The consultation
1. Background • Fifty-nine Scottish islands are currently connected to the electricity network that serves mainland Great Britain by the Scottish Hydro Electric Power Distribution network. • They are connected by submarine electricity cables that supply electricity to homes and businesses on the islands. • The combined length of these submarine electricity cables is 454km – with some sections having been in place for over 50 years. • The cost of supplying electricity to the Scottish islands is supported by electricity consumers across the north of Scotland as part of their energy bills.
2. What's changed? A statutory National Marine Plan for all activities in Scottish waters out to 200 nautical miles was adopted and published in March 2015. • Provides a single planning framework which will support the sustainable use of the marine resource • Includes policies on how submarine electricity cables are laid and protected on the seabed to achieve seabed user co-existence. • At present current installation practice is to lay cables directly on seabed • Changes to this practice and protecting cables will require significant increases in capital expenditure.
3. Who is involved? Ofgem • SHEPD are regulated by Ofgem who are responsible for protecting the interests of consumers and ensuring they have access to an affordable, secure and sustainable energy system. • Ofgem set the amount of revenue that SHEPD can receive, from consumers through their bill, in order to maintain the network. • Major investment decisions, such as changing the way we lay submarine cables, require approval from Ofgem • Our engineering activities within the marine environment are regulated by Marine Scotland.
3. Who is involved? Marine Scotland • SHEPD engineering activities within the marine environment are regulated by Marine Scotland • Marine Scotland is responsible for managing Scotland’s seas for prosperity and environmental sustainability. • It achieves this through its marine planning, licensing and other functions. • Marine Scotland produced Scotland’s National Marine Plan.
4. Why we are consulting We are developing a cost benefit analysis model which will help us demonstrate (to ourselves, our regulators and all users of the marine environment) that the methods we propose to use for laying and protecting cables around the coast of Scotland: • Satisfies current legislation • Employs the most sustainable method when considering economic, safety and wider social and environmental impacts We want to give our stakeholders a chance to shape the impacts and evidence we consider and our methodology
5. What’s happened so far? • SHEPD submit their business plan to Ofgem for the period April 2015- July March 2023 2013 • Ofgem and SHEPD agree the amount of revenue SHEPD can receive, from Nov customers through their electricity bills, in order to maintain the network 2014 • Scotland’s National Marine Plan adopted and laid before parliament March 2015 • Consultation live Sept – Oct 15
5. Project timeline
6. Submarine cables – installation methods Current practice • Surface lay Protection methods • Ploughing • Jetting • Mass Flow Excavation (MFE) • Mattressing • Rock dumping Source: subseaworldnews.com
6. Surface lay • The is the current method of submarine cable installation used by SHEPD • This method involves laying the cable directly on the seabed, above the surface, and therefore exposed to the surrounding elements • At present 110 out of the 111 submarine cables that SHEPD owns have been installed and are maintained using this method.
6. Ploughing • Ploughshare reaches down to the seabed and cuts a narrow channel • The cable can be guided down directly behind or guided through a hollow inside the plough • Results dependent upon suitable sediment coverage Source: subseacablesuk.org.uk
6. Jetting • Jetting tools consist of a row of water nozzles, which are pushed down into the seabed • Jetting relies on a high pressure water flow from nozzles, which fluidises the seabed • As the jetting tool is moved along the cable, the cable sinks down into the fluidised seabed, which re-solidifies Source: hudsonproject.com with settlement
6. Mass Flow Excavation (MFE) • Burial is achieved by passing over the cable route after installation and clearing sediment away from below the cable allowing the cable to bury naturally utilising the same sediment to back fill • As the sediment is liquefied, the cable is buried during the initial pass – this is an established industry method of burial. Source: subseaworldnews.com
6. Mattressing • Concrete mattress placement is mainly used for cable protection at localised areas of cable movement where burial is not achievable • Each mattresses weight is significant enough as not to be move by tidal flow • Edges are graded at an angle to reduce the impact upon fishing gear and/or anchors snagging Source: offshorewind.biz
6. Rock dumping • Rock dumping is used to protect the cable from third party hazards and not to protect marine users from the cable • Rock dumping creates an unnatural seabed feature that not only increases the surface area of the cable, and may reduce water depths by a few meters nearer the shore • This method increases the surface area and which maybe an additional hazard Source: offshorewind.biz to mariners • Due to the nature of rock dumping it cannot necessarily be graded as well as prefabricated concrete mattresses
7. Purpose of the Cost Benefit Analysis Assessment Stakeholder Engagement • To estimate the costs and benefits associated with different installation methods and to compare these with current practices for installing submarine cables Impacts included into CBA model • The four cost and benefit impact categories that will be considered are health and safety, socio-economic, environmental and engineering and wider economic • We will, with your help, calculate the value of each of the impacts in monetary terms, so they can be compared on an equivalent basis • The installation method with the greatest overall benefits (or least drawbacks) will be identified as best value • We define best value as the method(s) of installation which satisfy all current legislation and provide a sustainable balance of economic, safety, environmental and wider social and economic impacts
8. Health and safety impact pathway CBA Development Process • Risks of snagging on surface laid cables and rock-protected cables Activity • Damage to fishing nets, anchors, vessels, and machinery Impact • Fishery operators Receptors • Loss of catch in entangled nets • Damage to machinery or vessels • Down time during which fishing cannot occur Effects • Market value of lost catch • Damage costs to machinery or vessels • Opportunity cost of loss of fishing time Valuation
8. Total installation method impact valuation No. of Cost of Health and safety Total value snagging snagging (£) events events No. of Socio-economic power Cost of Total value outages outages (£) from faults Total (net) cost of installation method 1 Volume of Cost of Environmental Total value GHG GHG (£) emissions emissions Type of Cost of Total value Economic & cable cable (£) installation installation Engineering
8. Survey Data Surveying work has commenced on 8 cable routes: • Harris - Scalpay • Kintyre - Gigha • Mainland Orkney - Shapinsay • Mossbank - Yell • Shapinsay - Sronsay • Westray - Rousay • Yell – Unst (1) • Yell – Unst (2) Planned completion of survey work is February 2016
8. Survey Data
8. Output of Cost Benefit Assessment Costs and benefits of different submarine cable installation 600 techniques 400 Impacts included into CBA model 200 0 £'000 Costs Benefits Costs Benefits Costs Benefits Baseline Installation method 1 Installation method 2 -200 -400 -600 -800 Health and safety Socio-economic Environmental Engineering & wider economic
9. Getting involved We are seeking views on: • The cable installation methods we are considering • The potential benefits and costs of cable installation methods • If we have captured the impacts associated with different cable installation methods or if there are others we should consider • If there is any pre-existing data which would help demonstrate the impact of a cable installation method Consultation will close on 13 October 2015.
9. Overview of consultation Consultation paper Stakeholder survey Consultation website
9. Contact us Email: submarinecables@sse.com Website: www.news.ssepd.co.uk/submarinecables Postal address: Submarine cables CBA team Inveralmond House 200 Dunkeld road Perth Ph1 3AQ
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