Summer 2021 Project News Dinorwig to Pentir underground cable replacement project Earlier this year we shared details about our Since we last wrote to you, we’ve plans to replace the existing underground been continuing to develop our plans electricity cables between Dinorwig Power including carrying out engineering Station and our substation at Pentir. and environmental surveys to help us plan a route for the cables. We After nearly 40 years in service, the cables now can’t use the existing route because need replacing to make sure that electricity it’s vital that we keep the power supplies remain secure and reliable for the local station connected to the electricity area and beyond. network at all times. Phillip Webb, Lead Project We’ll keep the new connection underground so the In this newsletter you’ll find a map Manager, area will continue to look as it does now. Replacing showing the proposed route for the National Grid the cables falls within our Permitted Development replacement cables. We also rights, which means we don’t need additional explain more about our next steps planning permission to do our work. We’re working and when we’ll do our work. closely with important stakeholders, like Gwynedd Council and environmental bodies, to make sure We’ll continue to keep you up to date and share more that we follow their guidance. information about our plans as our work progresses. Who is National Grid and what do we do? National Grid owns the high-voltage electricity transmission network in Wales and England. We’re responsible for making sure electricity is transported safely and efficiently from where it’s produced to where it’s needed. We’re working to build a cleaner, fairer and more affordable energy system that serves everyone – powering the future of our homes, transport and industry. We believe by acting now the UK can become the world’s first major clean economy, with net zero carbon emissions by 2050. Project News | Dinorwig to Pentir underground cable replacement project First Hydro Company’s role First Hydro Company operates and maintains Making sure that there is a reliable connection Dinorwig Power Station. The station is a vital part between the station and the electricity network is of the electricity network in Wales and England. critical to operating the facility efficiently and safely. It provides fast-response power generation when We’re working with National Grid as it develops electricity consumption is at its peak: helping National its cable replacement plans to help make sure the Grid to maintain a reliable supply to British homes project runs as smoothly as possible. and businesses. John Armstrong, Station Manager, Dinorwig is also playing a key role in the nation’s low- First Hydro Company, ENGIE carbon energy future by supporting more renewable energy sources, such as wind and solar, connecting to the system. It enables this by providing electricity when weather conditions mean there is less renewable generation available. What happens next? We’re now preparing for early construction work to begin later this year. We’re finalising our plans and are appointing the contractors who will help us carry out the cable replacement. And we’re continuing to engage with landowners who we’ll need to work with to carry out this project. We’ll also be carrying out our routine maintenance work on the existing underground cables, up until we replace them. Later this year we’ll update you again on our work and what it will involve, but in the meantime, please get in touch if you have any questions about our project. Timeline This latest timeline provides an overview of the project programme. It’s important to know that our work won’t be visible all the time. We’ll work on different sections simultaneously and we’re agreeing a programme and conditions with Gwynedd Council, for example, we won’t be working on the main roads during the summer. Autumn 2021 Autumn 2023 2027 Construction starts, Cable installation Project is including on A4086 begins completed Early 2022 Autumn 2025 Construction work Works on highways begins on the A4244 completed Contact us Call our freephone number: 0330 1340066 Send an email to: [email protected] www.nationalgrid.com/uk/electricity-transmission/network-and-infrastructure/dinorwig-pentir Newyddion y Prosiect | Y prosiect i newid y ceblau tanddaear o Ddinorwig i Bentir Project News | Dinorwig to Pentir underground cable replacement project 1. Is-orsaf Pentir 1. Pentir Substation 1 Allwedd / Key Dyma’n his-orsaf lle mae’r ceblau’n cysylltu â This is our substation where the cables connect to Cylched Ceblau 1 Is-orsaf Pentir National Grid rhwydwaith trydan Cymru a Lloegr. Mae angen i the national electricity network. We need to extend Cable Circuit 1 National Grid Pentir Substation ni ei ehangu i wneud lle ar gyfer y ceblau newydd. this so it can accommodate the replacement cables. Cylched Ceblau 2 Compownd Pennau Selio National Grid Byddwn yn datgomisiynu’r ceblau tanddaear We’ll decommission the current underground cables Cable Circuit 2 National Grid Sealing End Compound presennol rhwng yr is-orsaf hon â Gorsaf Bŵer between this substation and Dinorwig Power Station Gorsaf Bŵer Dinorwig Dinorwig ac yn gosod tair cylched newydd. and install three new circuits. Cylched Ceblau 3 Dinorwig Power Station Cable Circuit 3 Trwy osod tair cylched newydd, gallwn gadw Gorsaf Installing three new circuits allows us to keep Bŵer Dinorwig wedi’i chysylltu â’r rhwydwaith tra Dinorwig Power Station connected to the network Lleoliad Drilio Cyfeiriadol Llorweddol byddwn yn gwneud ein gwaith. Mae hyn yn bwysig while we do our work. This is important as the Horizontal Directional Drilling Location gan fod yr orsaf yn chwarae rhan hanfodol yn station plays a vital role in providing fast response cynhyrchu trydan yn gyflym pan fydd angen. power when it’s needed. 2. Dilyn yr A4244 2. Following the A4244 2 Gosodir dwy gylched ceblau yn yr A4244. Mae hyn Two cable circuits will be installed in the A4244. yn ein helpu i amharu cyn lleied ag y bo modd ar y This helps us minimise the effects on the local dirwedd a’r amgylchedd. Bydd y drydedd gylched landscape and environment. A third circuit follows yn dilyn llwybr arall. another route. 5. I’r de o Lyn Padarn 5. South of Llyn Padarn Weithiau, bydd angen dulliau rheoli traffig, fel We will, at times, need to install traffic management, goleuadau dros dro, ar ddarnau byr o’r ffordd fel y such as temporary lights, along short sections Gosodir dwy gylched ceblau yn yr A4086 ac Two cable circuits will be installed in the A4086 and gallwn weithio’n ddiogel. Ni fydd hyn yn para trwy of road so that we can carry out our work safely. ymlaen i’r de o Lyn Padarn. Fel gyda’n gwaith ar yr continue south of Llyn Padarn. As with our work on gydol y prosiect. Rydym yn cydweithio’n agos â This won’t be for the duration of the project. We’re A4244, bydd angen defnyddio dulliau rheoli traffig, the A4244, we will, at times, need to install traffic thîm priffyrdd Cyngor Gwynedd a byddwn yn cadw working closely with Gwynedd Council’s highways fel goleuadau dros dro, weithiau, ar y darn hwn o’r management, such as temporary lights, on this part mewn cysylltiad â chi ynglŷn ag unrhyw effaith team and will continue to keep you updated about ffordd fel y gallwn weithio’n ddiogel. Yna, bydd y of the road so we can work safely. The cables will bosibl ar ffyrdd yr ardal. any potential effect on the local road network. ceblau’n mynd y tu ôl i adeilad y Mynydd Gwefru ac then pass behind the Electric Mountain building and ymlaen i gyfeiriad Gorsaf Bŵer Dinorwig. then run towards Dinorwig Power Station. 3 6. Croesi rhwystrau 6. Navigating obstacles A4244 Bydd angen i’n ceblau newydd groesi nifer o Our new cables will need to cross some obstacles rwystrau nad ydym yn awyddus i darfu arnynt na’u that we don’t want to disturb or close, such as cau, fel afonydd a ffyrdd. Byddwn yn defnyddio rivers and roads. We’ll use a drilling technique techneg ddrilio o’r enw Drilio Cyfeiriadol Llorweddol called Horizontal Directional Drilling to install our (HDD) i osod ein ceblau o dan y rhwystrau hyn. cables underneath these obstacles. 3. Defnyddio cysylltiad 3. Using our existing Llwybrau troed a llwybrau Local paths and bridleways presennol y llinell uwchben overhead line connection ceffylau We’re working hard to minimise the affects of our A4086 work on footpaths and bridleways. Where closures Mae llinell uwchben yn cysylltu Pentir â An overhead line already connects between Pentir Rydym yn gweithio’n galed i leihau effeithiau ein are necessary so that we can carry out our work chompownd pennau selio’r ceblau ym Mhenisa’r- and our cable sealing end compound at Penisa’r 4 gwaith ar lwybrau troed a llwybrau ceffylau. Os safely, we’ll signpost a diversion. waun. Bydd cylched ceblau tanddaear newydd yn Waun. A new underground cable circuit will bydd angen eu cau fel y gallwn weithio’n ddiogel, rhedeg oddi yma i Ddinorwig gan groesi o dan afon connect from here to Dinorwig crossing under the byddwn yn codi arwyddion gwyriad. Rhythallt ac ar hyd yr A4086. Afon Rhythallt and along the A4086. 4. I’r gogledd o Lyn Padarn 4. North of Llyn Padarn 5 Bydd un o’r ddwy gylched ceblau a osodir yn yr One of the two cable circuits installed in the A4244 A4244 yn mynd ymlaen i’r gogledd o Lyn Padarn, will continue to the north of Llyn Padarn, following gan ddilyn llwybr ein cebl presennol, ac i Orsaf the route of our existing cable, and into Dinorwig Bŵer Dinorwig.