Mid‑Wales grid plans: Slimmer monopole pylons proposed 2026

Key Points

• Green Gen Cymru has unveiled new monopole pylon designs for two of their three proposed mid-Wales electricity lines.
• The monopoles will stand at an approximate height of 22m and have a diameter of 1m, taking the place of 27-28m steel lattice pylons on the Tywi-Usk and Tywi-Teifi schemes.
• They are expected to roll out a prototype by the start of 2027, and the company hopes that some of the manufacturing process can take place in Wales.
• The developer claims that the smaller structures reduce visual pollution and land use while having enough capacity of 132kV power network.
• Activists and some landowners are still against these proposals, stating that they do not conform to the promise for undergrounding and “low wooden poles or equivalent” made in Plaid Cymru’s manifesto.
• Green Gen Cymru has announced investment of nearly £1bn into electricity infrastructure in Wales by 2030.

Wales (Wales Times) September 17, 2026 – New designs have been published for the pylons planned to stretch across mid Wales to link onshore windfarms with the National Grid, as energy developer Green Gen Cymru seeks to address long‑running controversy over its proposed “pylon superhighways”. The company announced on Thursday that it has designed a replacement structure – a single‑pole steel “monopole” – to use instead of the traditional steel lattice pylons it had previously proposed for two of its three major routes.

As reported by Ruth Mosalski of WalesOnline, Green Gen Cymru hopes to build three major electricity pylon routes connecting onshore windfarms planned by its sister company Bute Energy through a combined 200km of Powys, Ceredigion and Carmarthenshire. The newly revealed monopole would typically be taller than the wood pole structures being considered but shorter and with a smaller ground footprint than the L7 steel lattice pylons originally under consideration.

How do the monopoles compare with earlier pylon plans?

Green Gen Cymru were proposing L7 steel lattice structures which were between 27 and 28 metres high and 4m wide with a ground footprint of 7.5m, according to details outlined by WalesOnline. The alternative monopole design would be 22m high with a 1m diameter, while still able to be used at around four structures per kilometre, broadly replacing the steel structures like‑for‑like in terms of span length.

As reported by Martin Shipton of Nation.Cymru, monopole pylons around 22 metres tall are being proposed for the Tywi‑Usk and Tywi‑Teifi projects, around half the height of a typical 275kV pylon. According to Green Gen Cymru, the monopoles are based on a Danish design and have been created specifically for the requirements of its developing 132kV network, and with the Welsh landscape in mind.

The company says monopoles will now be considered alongside wood poles, lattice towers and underground cables as part of its infrastructure “toolkit”, with opportunities also being explored for the structures to be manufactured and fabricated in Wales. Andrew Hardcastle, Executive Director at Green Gen Cymru, said: “As demand for electricity increases, Wales will need more network capacity to connect new energy generation, support businesses, strengthen communities, improve productivity and attract inward investment.” He added that there was no single solution suitable for every landscape or community and that developing monopoles alongside other options would give the company greater flexibility.

Why has Green Gen Cymru changed the pylon design?

Autto Davies, head of planning and affairs at Green Gen Cymru, indicated that various factors prompted the company to seek an alternative pylon design, including “engineering and environmental considerations, community feedback, and the political context in which we’re operating”, as quoted by BBC News. He said: “We’ve endeavoured to challenge ourselves to discover an innovative approach” that aligns with “Wales’ economic, productivity, and decarbonisation goals while also addressing the needs of the communities hosting this infrastructure.”

Stephen Rowlands, the company’s head of construction and supply chain, remarked on “the real opportunity for Welsh industry to take a leading role” in the development and delivery of the new pylons. He said: “As we advance the monopole, we aim to leverage the skills, expertise, and manufacturing capabilities available here in Wales.” Green Gen Cymru says it intends to engage with potential manufacturing partners across Wales as the design progresses, with the aim of developing a Welsh supply chain around the technology.

The monopoles will be fabricated from structural steel, requiring steel fabrication, forming and welding, alongside associated engineering and finishing processes. In developing the design, consideration has been given to construction requirements, deliverability and the opportunity to draw on existing Welsh skills, fabrication capability and engineering expertise.

What do campaigners and local residents say about the new pylons?

There has been huge opposition to Green Gen Cymru’s plans, with large and active campaign groups particularly in the areas impacted by the Towy Usk and Towy Teifi projects, as reported by WalesOnline. The developer has been criticised by farmers and landowners who claim that agents on their behalf are trying to force their way onto land to conduct surveys for pylon highways, and Green Gen Cymru has been taken to court by landowners and faced criticism from a judge for the way impacted landowners were treated.

As reported by BBC News, Dr Dean of the Campaign for the Protection of Rural Wales said the new design would not appease critics of the company’s initiatives, stating: “It remains a significant piece of infrastructure in the countryside.” Farmer Dyfan Walters, residing near one of the proposed pylon routes on the outskirts of Llandovery in Carmarthenshire, said: “Undergrounding is the only option we would consider, which aligns closely with the Plaid Cymru policy.” He added that while many would still find the new pylons unacceptable, the company’s necessity to amend original plans could be viewed “as a win for the community”.

In Carmarthen, members of the public offered mixed views to BBC News. Georgia Rollinson, 27, said the new design appeared “a little bit better” and might “integrate more seamlessly”, while Anthony Read, 69, said: “They certainly seem smaller and more appealing, but ideally, they should be placed underground.” Phillip Richardson, 78, questioned: “Why invest in replacing pylons with something that is only slightly better?” whereas Robin Daniels, 58, said they looked “much better than the traditional ones” and could be a positive development if they lessen visual disturbance.

The proposed change was immediately opposed by campaigners from the Llandovery Pylon Steering Group, who said the new structures were neither “low” nor “less intrusive” than the lattice pylons they would replace, according to Nation.Cymru. The group pointed out that the proposed monopoles would be more than twice the height of a typical nine‑metre telegraph pole and claimed the structures could require significantly closer spacing than lattice pylons, potentially every 150 to 180 metres compared with around 250 metres for pylons. Campaigners estimate this could result in between 150 and 220 additional structures along the Tywi‑Usk route alone.

A spokesperson for the Llandovery Pylon Steering Group said:

“Replacing one form of massive, intrusive overhead infrastructure with another is not the undergrounding‑led approach that was promised to Welsh communities.”

The group called on Plaid Cymru and the Welsh Government to uphold the commitment to a presumption in favour of undergrounding and invited elected representatives and members of the public to attend Green Gen Cymru’s consultation event in Llandovery on October 15.

How do the plans fit with Welsh Government and Plaid Cymru policy?

The plans have been in focus since the election of the Plaid Cymru government, which had said in its manifesto it would “immediately prohibit the use of large steel lattice pylons for new 11–132kV lines in Wales, with a clear presumption in favour of undergrounding and overhead alternatives permitted only where installation is via low wooden poles or equivalent, less intrusive infrastructure”, as reported by WalesOnline. When it was most recently discussed in the Senedd, on July 8, the rural affairs minister had said “current policy sets out a presumption in favour of the undergrounding of grid infrastructure” but said a more detailed statement would follow.

Adam Price, the minister whose brief pylons falls under, told the Senedd they believed 132kV pylons “should be undergrounded”. He said: “We will not allow pylons on new lines. The only exceptions would involve wooden poles or similarly unobtrusive infrastructure.” “I want to be absolutely clear: our policy is clear on this—we do not see a role for pylons on new lines in the distribution network.”

The Welsh Government remarked that it would be inappropriate to comment on proposals due to the role Welsh ministers play in the process, according to BBC News. A spokesperson added: “We are formulating a National Energy Strategy to ensure that Wales meets its energy needs sustainably and benefits its people and communities.”

Background to the pylon superhighways development

Green Gen Cymru aims to construct three significant powerline routes connecting onshore wind farms planned by its sister company, Bute Energy, with the broader grid network, affecting areas in Carmarthenshire, Ceredigion, Powys and Shropshire. The company has pledged to invest nearly £1bn by 2030 in new electricity infrastructure, arguing that electricity demand in Wales could almost triple by 2050. The monopoles form part of a wider programme to increase network capacity, with the company having already secured approval and completed type‑testing of the ACCC uk/local/cardiff/">Cardiff conductor, which it says can carry significantly more electricity than conventional conductors while allowing slimmer structures.

National context also matters: a £70bn programme is under way to modernise Great Britain’s network of pylons, overhead lines and substations so that more power can be carried from wind and solar farms and other clean energy sources to homes, according to the Guardian. The National Audit Office has warned that failure to implement such modernisation would hold back economic growth and could lead to higher bills. Within Wales, separate proposals for new transmission lines under review by the National Energy System Operator (NESO) could also affect the strategic need for some of Green Gen Cymru’s planned routes, as noted by the Campaign for the Protection of Rural Wales.

Prediction: How could this development affect communities and stakeholders in mid‑Wales?

If the monopole design is accepted and built, residents in Powys, Ceredigion and Carmarthenshire are likely to see a somewhat reduced visual footprint compared with the original lattice towers, but still face new industrial‑scale structures crossing rural landscapes. For farmers and landowners, the smaller ground footprint could mean less land take per structure, although campaigners warn that closer spacing could increase the total number of structures on some routes. For local supply chains, the push to fabricate and manufacture monopoles in Wales could create engineering and steelwork jobs, provided contracts are secured with Welsh firms.

For the Plaid Cymru‑led Welsh Government, the shift to monopoles tests its manifesto commitment on undergrounding and “low wooden poles or equivalent”, and may shape how strictly that policy is interpreted in planning decisions. For energy consumers and climate targets, faster grid expansion using higher‑capacity conductors and slimmer supports could help connect more renewable generation, potentially lowering long‑term system costs if delays and legal challenges are reduced. However, if opposition remains strong and legal challenges continue, project timelines could slip, risking higher near‑term costs and slower progress towards decarbonisation goals.