Pentir to Trawsfynydd reinforcement / Atgyfnerthu’r cysylltiad rhwng Pentir a Thrawsfynydd

Wales / Cymru

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Prosiect atgyfnerthu’r cysylltiad rhwng Pentir a Thrawsfynydd

Mae angen i National Grid greu is-orsaf newydd ym Mryncir a newid y ceblau trydan tanddaear sy’n croesi Aber Afon Glaslyn ger Porthmadog a Thremadog.

Bwriad hyn yw ein galluogi i sicrhau bod ynni adnewyddadwy glân yng ngogledd Cymru'n cael ei gysylltu'n ddiogel â’r grid, gan gynnal cyflenwadau trydan dibynadwy ar gyfer cartrefi a busnesau yn yr ardal a'r tu hwnt.

Y newyddion diweddaraf (Mawrth 2023)

Erbyn hyn, rydym wedi penodi Murphy Power Networks i fod yn brif gontractor i gynllunio llwybr y ceblau a fydd yn rhedeg o dan y ddaear rhwng y Wern a'r Garth, yn cynnwys mynd o dan Aber Afon Glaslyn ger Porthmadog a Thremadog.

Er mwyn casglu gwybodaeth i gyfrannu at y cynllun, byddant yn dechrau cynnal arolygon anymwthiol ar y ddaear yn Aber Afon Glaslyn a'r cylch o ganol mis Mawrth 2023 ymlaen.

Bydd y gwaith gweladwy arall yn cynnwys cael rhywun sydd wedi'i hyfforddi'n arbennig i ddefnyddio drôn i gynnal arolygon o'r awyr. Bydd y tirfeddianwyr wedi cael gwybod am hyn ac wedi rhoi eu caniatâd.

Ar sail ein llinell amser bresennol, disgwyliwn y bydd y gwaith adeiladu'n dechrau rhwng canol a diwedd 2025.

Gosodwyd y ceblau presennol ddiwedd yr 1970au ac maent wedi cael eu defnyddio byth er hynny. Erbyn hyn, maent yn cyrraedd diwedd eu hoes weithredol ac mae angen eu newid er mwyn sicrhau bod y cyflenwadau trydan i’r ardal leol a’r tu hwnt yn dal yn gadarn.

Yn ogystal, mae angen i ni uwchraddio’r rhwydwaith lleol â cheblau ychwanegol, fel y gallwn drawsyrru’r ynni glân, adnewyddadwy o’r ffermydd gwynt newydd y bwriedir eu datblygu yn y môr oddi ar lannau’r gogledd. Mae’r gwaith hwn yn bwysig er mwyn datblygu system ynni lanach, decach a mwy fforddiadwy sy’n gwasanaethu pawb – gan bweru ein cartrefi, ein trafnidiaeth a’n diwydiant i’r dyfodol.

Bu gennym fwriad i wneud gwaith tebyg rai blynyddoedd yn ôl i ddarparu ar gyfer ynni fyddai’n cael ei gynhyrchu gan Horizon Nuclear Power yng ngorsaf Wylfa Newydd ond nid yw’r cynllun hwnnw’n mynd ymlaen bellach.

Fel o'r blaen, mae’r gwaith hwn ar wahân i’n Prosiect Darpariaeth Effaith Weledol (VIP), sy’n golygu cael gwared â rhan o’r llinell uwchben mewn rhan weledol-sensitif o Barc Cenedlaethol Eryri a rhoi ceblau trydan mewn twnnel o dan y ddaear yn ei lle. Mae hefyd ar wahân i’n gwaith o newid ceblau tanddaear rhwng Gorsaf Bŵer Dinorwig a’n his-orsaf ym Mhentir. Rydym yn cydweithio’n agos ag eraill ar y prosiectau hyn er mwyn sicrhau bod ein gwaith yn gydgysylltiedig ac yn effeithlon.

Byddwn yn rhoi rhagor o wybodaeth ar y dudalen hon wrth i’n gwaith symud ymlaen.

Pentir to Trawsfynydd reinforcement project

National Grid needs to create a new substation in Bryncir and replace underground electricity cables across the Glaslyn Estuary near Porthmadog and Tremadog.

This is so we can safely connect clean renewable energy in North Wales to the grid, while also maintaining the security of electricity supplies for homes and businesses in the local area and beyond.

Latest update (March 2023)

We have now appointed Murphy Power Networks as our main contractor to design the route for the cables that will run underground between Wern and Garth, including beneath the Glaslyn Estuary near Porthmadog and Tremadog.

To gather information to inform the design, they will begin carrying out non-intrusive surveys on the ground at and around the Glaslyn Estuary starting from mid-March 2023 onwards.

Other visible work will involve use of a drone with a fully trained specialist operator to survey from the air. This will be done with the knowledge and permission of the landowners.

Based on our current timeline, we expect construction work will then start in mid to late 2025.

The existing cables were installed in the late 1970’s and have been in use ever since. They are now coming to the end of their operational life and need replacing to maintain the security of electricity supplies for the local area and beyond.

We also need to upgrade the network locally with additional cables, so we can transmit the clean renewable energy from proposed new offshore wind farms in North Wales. This work is an important part of building a cleaner, fairer and more affordable energy system that serves everyone – powering the future of our homes, transport and industry.

We previously proposed similar work some years ago to support generation from Horizon Nuclear Power’s proposed Wylfa Newydd project, which is no longer going ahead.

As before, this work is separate from our ongoing Visual Impact Provision (VIP) Project, which is removing a section of overhead line in a visually sensitive part of Snowdonia National Park and replacing it with electricity cables buried in a tunnel. It's also separate from our work to replace underground cables between Dinorwig Power Station and our Pentir substation. We are working closely with our colleagues on these projects to ensure our work is coordinated and efficient.

We will keep this web page updated with further information as our work progresses.