Scottish and Southern Energy Power Distribution Submarine - - PowerPoint PPT Presentation

Scottish and Southern Energy Power Distribution

Submarine electricity cables consultation

Open door events were held:

Stornoway 9th September 2015 Oban 15th September 2015 Campbeltown 16th September 2015 Aberdeen 28th September 2015 Kirkwall 29th September 2015 Lerwick 1st October 2015

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?

July 2013

• SHEPD submit their business plan to Ofgem for the period April 2015-

March 2023

Nov 2014

• Ofgem and SHEPD agree the amount of revenue SHEPD can receive, from

customers through their electricity bills, in order to maintain the network

March 2015

• Scotland’s National Marine Plan adopted and laid before parliament

Sept – Oct 15

• Consultation live

• 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 with settlement

Source: hudsonproject.com

• 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 to mariners

• Due to the nature of rock dumping it

cannot necessarily be graded as well as prefabricated concrete mattresses

Source: offshorewind.biz

Impacts included into CBA model

Stakeholder Engagement

• To estimate the costs and benefits associated with different installation methods and to

compare these with current practices for installing submarine cables

• 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

• 7. Purpose of the Cost Benefit Analysis Assessment

CBA Development Process

• 8. Health and safety impact pathway

Activity

• Risks of snagging on surface laid cables and rock-protected cables

Impact

• Damage to fishing nets, anchors, vessels, and machinery

Receptors

• Fishery operators

Effects

• Loss of catch in entangled nets
• Damage to machinery or vessels
• Down time during which fishing cannot occur

Valuation

• Market value of lost catch
• Damage costs to machinery or vessels
• Opportunity cost of loss of fishing time

• No. of

power

• utages

from faults Cost of

• utages

Total value (£)

• No. of

snagging events Cost of snagging events Total value (£) Volume of GHG emissions Cost of GHG emissions Total value (£) Type of cable installation Cost of cable installation Total value (£)

Total (net) cost of installation method 1

• 8. Total installation method impact valuation

Health and safety Socio-economic Environmental Economic & 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

Impacts included into CBA model

• 800
• 600
• 400
• 200

200 400 600 Costs Benefits Costs Benefits Costs Benefits Baseline Installation method 1 Installation method 2 £'000

Costs and benefits of different submarine cable installation techniques

Health and safety Socio-economic Environmental Engineering & wider economic

• 8. Output of Cost Benefit Assessment

• 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

• thers 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