Is-orsaf Llandyfaelog
Yn ddiweddar cyflwynom ni ein cais cynllunio ar gyfer is-orsaf 400kV Llandyfaelog i Gyngor Sir Gâr. Mae’r cyngor wedi dilysu’r cais cynllunio (cyfeirnod rhif PL/10552), a gallwch weld y dogfennau cais ar borth cynllunio ar-lein Cyngor Sir Gâr yma. Mae hyn yn dilyn Ymgynghoriad Cyn Ymgeisio (PAC) a gynhaliom ar y prosiect ddiwedd 2025. Daeth yr ymgynghoriadau i ben ar 16 Rhagfyr 2025, ac rydym wedi ystyried yr holl ymatebion a dderbyniwyd yn ofalus. Mae adborth o’r ymgynghoriad hwn wedi ei ymateb iddo yn yr adroddiad PAC sydd wedi’i atodi gyda’n cais cynllunio.
Mae National Grid yn cynnig gosod is-orsaf 400 kV newydd ger Llandyfaelog, i'r de o Gaerfyrddin, er mwyn helpu i ateb y galw cynyddol am drydan yn Ne a De-Orllewin Cymru.
Rydyn ni’n adeiladu’r is-orsaf i ymateb i geisiadau cysylltu y mae NGET wedi’u derbyn yn Ne Cymru gan Green GEN Cymru a National Grid Energy Distribution (NGED).
Mae dyletswydd gyfreithiol ar NGET i gysylltu cwsmeriaid â'n rhwydwaith pan ofynnir am gysylltiad. Pan nad oes gan is-orsafoedd presennol y capasiti ar gyfer maint y cysylltiad sydd ei angen, mae’n ofynnol i ni adeiladu un newydd i ddiwallu’r angen. Yn yr achos hwn, rydyn ni’n cynnig is-orsaf newydd ger Llandyfaelog.
NGET fydd yn berchen ar, ac yn cynnal, yr is-orsaf 400kV arfaethedig ger Llandyfaelog. Bydd y Gweithredwyr Rhwydwaith Ardal (DNO) / DNOau Annibynnol (iDNOau) angen eu his-orsafau eu hunain ochr yn ochr â’r is-orsaf NGET 400 kV a bydd yn gyfrifol am sicrhau eu caniatâd cynllunio eu hunain. Mae pob un prosiect yn wahanol i'w gilydd ac yn gyfrifol am sicrhau caniatâd cynllunio unigol ar gyfer unrhyw seilwaith arfaethedig.
Ble mae safle’r is-orsaf arfaethedig?
Byddai’r is-orsaf newydd tua 6km i’r de o Gaerfyrddin. Cynigir mynediad i’r safle o ffordd fynediad newydd a fydd yn cysylltu â’r A484.
Beth yw is-orsafoedd a sut maen nhw’n gweithio?
Mae is-orsafoedd yn rhannau hanfodol o’r rhwydweithiau trawsyrru a dosbarthu ac yn sicrhau bod trydan yn gallu cael ei drawsyrru ar wahanol folteddau, mewn ffordd ddiogel a dibynadwy.
Un o brif swyddogaethau is-orsafoedd yw trosi trydan yn wahanol folteddau. Mae hyn yn angenrheidiol fel y gall y trydan gael ei drosglwyddo o amgylch y wlad ac yna ei ddosbarthu drwy gymdogaethau lleol ac i mewn i’n cartrefi, busnesau ac adeiladau.
Mae NGET yn cymryd trydan sydd wedi'i gynhyrchu o ffynonellau pŵer ac yn ei gludo drwy ei rwydweithiau o linellau uwchben, ceblau, ac is-orsafoedd. Bydd wedyn yn cael ei drosglwyddo i foltedd is drwy rwydweithiau dosbarthu lleol i gartrefi a busnesau.
Pam mae angen yr is-orsaf newydd?
Mae National Grid yn cynnig gosod is-orsaf 400 kV newydd ger Llandyfaelog, i'r de o Gaerfyrddin, er mwyn helpu i ateb y galw cynyddol am drydan yn Ne a Ne-Orllewin Cymru.
Rydyn ni’n adeiladu’r is-orsaf i ymateb i geisiadau cysylltu y mae NGET wedi’u derbyn yn Ne Cymru gan Green GEN Cymru a National Grid Energy Distribution (NGED).
Mae dyletswydd gyfreithiol ar NGET i gysylltu cwsmeriaid â'n rhwydwaith pan ofynnir am gysylltiad. Pan nad oes gan is-orsafoedd presennol y capasiti ar gyfer maint y cysylltiad sydd ei angen, mae’n ofynnol i ni adeiladu un newydd i ddiwallu’r angen. Yn yr achos hwn, rydyn ni’n cynnig is-orsaf newydd ger Llandyfaelog.
NGET fydd yn berchen ar, ac yn cynnal, yr is-orsaf 400kV arfaethedig ger Llandyfaelog. Bydd y DNOau/iDNOau a’r dosbarthwyr angen eu his-orsafoedd eu hunain ochr yn ochr â'r is-orsaf 400 kV NGET a byddant yn gyfrifol am sicrhau eu caniatâd cynllunio eu hunain. Mae pob un prosiect yn wahanol i'w gilydd ac yn gyfrifol am sicrhau caniatâd cynllunio unigol ar gyfer unrhyw seilwaith arfaethedig.
Bydd yr is-orsaf arfaethedig ger Llandyfaelog yn helpu i ateb y galw am drydan yn Ne a De-Orllewin Cymru.
Llyfrgell Dogfennau
Yma gallwch ddod o hyd i gopïau o’r cais a’r cynlluniau arfaethedig, a dogfennau atodol eraill y bu i ni eu paratoi cyn cyflwyno ein cais i Gyngor Sir Gâr. Fel dogfennau technegol, dim ond yn Saesneg mae’r rhain ar gael. Mae’r Datganiad Cynllunio ar gael yn Gymraeg ac yn Saesneg.
Dogfennau Cyffredinol
Gallwch weld holl ddogfennau’r cais ar gyfer yr is-orsaf 400kV a gynigir, ar borth cynllunio Cyngor Sir Gaerfyrddin yma (rhif cais PL/10552).
Mae’r dogfennau hyn yn cynnwys y Datganiad Cynllunio, yr Adroddiad Ymgynghori Cyn-ymgeisio, a’r asesiadau a’r arolygon amgylcheddol a thechnegol
Beth sy'n digwydd nesaf?
Ar ddiwedd 2025, fe wnaethom wedyn gynnal Ymgynghoriad Cyn Ymgeisio (PAC) statudol ar gyfer yr is-orsaf. Dechreuodd yr ymgynghoriad ar 18 Tachwedd 2025, gan ddod i ben ar 16 Rhagfyr 2025.
Mae’r ymgynghoriad hwn, wedi’i gynnal yn unol â deddfwriaeth Llywodraeth Cymru, yn rhan bwysig o’r broses gynllunio ac wedi rhoi’r cyfle i ni geisio adborth yn ffurfiol ar ein cynigion cyn cyflwyno cais.
Rydym wedi ystyried yr holl ymatebion a dderbyniwyd yn ofalus. Mae adborth o’r ymgynghoriad hwn wedi ei ymateb iddo yn yr adroddiad Ymchwiliad Cyn Ymgeisio sydd wedi’i atodi gyda’n cais cynllunio.
Rydym nawr wedi gorffen ein cynlluniau’n derfynol ac wedi cyflwyno ein cais cynllunio i Gyngor Sir Gâr.
Mae’r cyngor wedi dilysu’r cais cynllunio (cyfeirnod rhif PL/10552), a gallwch weld y dogfennau cais ar borth cynllunio ar-lein Cyngor Sir Gâr yma:
Bydd Cyngor Sir Gâr nawr yn asesu cais yr is-orsaf ac yn rhoi eu hymgynghoriad eu hunain ynghylch y cais ar waith maes o law. Rydym yn disgwyl derbyn penderfyniad gan Gyngor Sir Gâr yn y misoedd sydd i ddod.
Sut mae cael yr wybodaeth ddiweddaraf am is-orsaf arfaethedig Llandyfaelog?
Gallwch gofrestru eich diddordeb yma i gael yr wybodaeth ddiweddaraf am is-orsaf arfaethedig Llandyfaelog.
Os oes gennych chi unrhyw gwestiynau am is-orsaf arfaethedig Llandyfaelog, gallwch hefyd gysylltu â’n tîm cysylltiadau cymunedol drwy:
E-bost: [email protected]
Ffôn: 0800 915 3595
Post: FREEPOST NG Llandyfaelog
Llandyfaelog Substation
We recently submitted our planning application for the Llandyfaelog 400kV substation to Carmarthenshire County Council. The council has validated the planning application (reference number PL/10552), and you can view the application documents on Carmarthenshire County Council’s online planning portal here. This follows a Pre-Application Consultation (PAC) we held in late 2025 on the project. The consultations closed on 16 December 2025, and we have carefully considered all the responses received. Feedback from this consultation has been responded to in the Pre-Application Consultation report that accompanies our planning application.
National Grid is proposing a new 400 kV substation near Llandyfaelog, south of Carmarthen, to help meet the growing demand for electricity in South and South-West Wales.
We are building the substation in response to connection requests NGET has received in South Wales from Green Gen Cymru and National Grid Energy Distribution (NGED).
NGET has a legal obligation to connect customers to our network when a connection is requested. When existing substations do not have the capacity for the size of the connection required, we are required to build a new one to meet the need. In this case, we are proposing a new substation near Llandyfaelog.
NGET will own and maintain the proposed 400 kV substation near Llandyfaelog. The District Network Operators (DNOs) / Independent DNOs (iDNOs) will require their own substations alongside the NGET 400 kV substation and will be responsible for securing their own planning permission. Each project is distinct from one another and is responsible for securing individual planning permissions for any proposed infrastructure.
Where is the site of the proposed substation?
The new substation would be located around 6km south of Carmarthen. Site access is proposed to be from a new access road which will connect to the A484.
What are substations and how do they work?
Substations are critical parts of the transmission and distribution networks and enable electricity to be transmitted at different voltages, securely and reliably.
One of the main roles of substations is to convert electricity into different voltages. This is needed so the electricity can be transmitted around the country and then distributed throughout local neighbourhoods and into our homes, businesses and buildings.
NGET takes electricity generated from power sources and transports it through its network of overhead lines, cables, and substations. It is then transmitted at a lower voltage via the local distribution networks (DNOs) to homes and businesses.
Why is our new substation needed?
National Grid is proposing a new 400 kV substation near Llandyfaelog, south of Carmarthen, to help meet the growing demand for electricity in South and South-West Wales.
We are building the substation in response to connection requests NGET has received in South Wales from Green Gen Cymru and National Grid Energy Distribution (NGED).
NGET has a legal obligation to connect customers to our network when a connection is requested. When existing substations do not have the capacity for the size of the connection required, we are required to build a new one to meet the need. In this case, we are proposing a new substation near Llandyfaelog.
NGET will own and maintain the proposed 400 kV substation near Llandyfaelog. The DNOs/iDNOs will require their own substations alongside the NGET 400 kV substation and will be responsible for securing their own planning permission. Each project is distinct from one another and is responsible for securing individual planning permissions for any proposed infrastructure.
The proposed substation near Llandyfaelog will help meet electricity demand in South and South-West Wales.
Document Library
Here you can find copies of the proposed application, the plans, and other supporting documents we prepared prior to our application submission to Carmarthenshire County Council. As technical documents, these are available in English only. The Planning Statement is available in Welsh and English.
General Documents
You can view all the application documents for the proposed 400kV substation on Carmarthenshire County Council’s planning portal here (application number PL/10552).
These documents include the Planning Statement, Pre-Application Consultation Report, and environmental and technical assessments and surveys.
What happens next?
In late 2025, we carried out a statutory Pre-Application Consultations for the substation. The consultation began on 18 November 2025 and closed on 16 December 2025.
This consultation, conducted in line with Welsh Government legislation, is an important part of the planning process and gave us the opportunity to formally seek feedback on our proposals ahead of formal submission.
We have carefully considered all the responses received. Feedback from this consultation has been responded to in the Pre-Application Consultation report that accompanies our planning application.
We have now finalised our plans and submitted our planning application to Carmarthenshire County Council.
The council has validated the planning application (reference number PL/10552), and you can view the application documents on Carmarthenshire County Council’s online planning portal here.
Carmarthenshire County Council will now assess the substation application and carry out its own consultation on the application in due course. We expect to receive a decision from Carmarthenshire County Council in the coming months.
How can I keep informed about the proposed Llandyfaelog substation?
You can register your interest here to receive project updates about the proposed Llandyfaelog substation.
If you have any questions about the proposed Llandyfaelog substation, you can also get in touch with our community relations team via:
Email: [email protected]
Phone: 0800 915 3595
Post: FREEPOST NG Llandyfaelog