The Welsh Government has launched a consultation on plans to make underground cables the preferred option for new electricity lines, in a move that could have implications for future energy infrastructure across North Wales.

The proposed policy would apply to new electricity lines operating between 11,000 and 132,000 volts, with overhead alternatives allowed only when specified planning tests are met. Where overhead lines are permitted, the preference would be for low wooden poles or similarly less intrusive structures rather than large steel lattice pylons.

The consultation follows the Welsh Government’s commitment to end the use of large steel pylons for new electricity lines within its devolved planning responsibilities.

Cabinet Minister for Enterprise, Connectivity and Energy Adam Price said the transition to a low-carbon energy system was central to the ambition of reaching net zero by 2040.

He said new grid infrastructure would be needed as the way electricity was generated and used changed, but it was important to minimise the impact on communities and the environment.

The consultation will seek views on how the policy should work in practice, including its design and operation.

The proposals come amid growing debate over how electricity generated by renewable energy projects should be transported across Wales, and whether communities should have to accept large pylons across the countryside to accommodate the changing energy system.

North Wales has already experienced controversy over electricity infrastructure. The North Wales Connection project, developed to support the proposed Wylfa Newydd nuclear power station on Anglesey, included plans for a major overhead electricity connection across the island and towards the mainland.

The prospect of additional pylons has prompted concerns about the effect on rural landscapes, views, wildlife, tourism and the quality of life of people living near proposed routes.

Campaigners have also questioned whether developers have given underground cabling sufficient consideration, particularly in areas valued for their scenery and environmental importance.

More recently, proposals for new electricity connections associated with renewable energy developments have fuelled debate about the scale of infrastructure needed in mid and north Wales, and how much of the electricity generated locally will be used in Wales or transported elsewhere.

The National Infrastructure Commission for Wales has identified a need to expand the electricity network, while warning that uncertainty over planning policy and the cost of different approaches can contribute to delays for grid and renewable energy projects.

If adopted, the undergrounding-first policy could make a difference to the appearance of the countryside where new electricity lines are required at the covered voltage levels. It could reduce the number of new steel pylons in areas where overhead infrastructure would otherwise be considered, including rural communities and landscapes important to tourism.

However, the policy would not automatically remove existing pylons, nor would it necessarily prevent every new overhead line. Its application would depend on the voltage, planning arrangements and whether an alternative met the relevant tests.

It is also important to distinguish between distribution and higher-voltage transmission infrastructure. The new policy concerns lines up to 132kV, while decisions on higher-voltage lines are generally reserved to the UK Government. That means some of the largest strategic electricity transmission projects affecting Wales may not fall within the same policy.

There are also questions about cost and delivery. Underground cables can be considerably more expensive to install than overhead lines, depending on the voltage, terrain and construction method. An independent advisory group examining Wales’s future electricity grid found that undergrounding at 132kV could cost between 2.2 and 2.8 times as much over its lifetime as overhead lines supported by towers. At lower voltages, the difference can be greater when underground cables are compared with cheaper wooden-pole networks.

Those additional costs could affect how quickly new connections are built and the economics of renewable energy developments. The ultimate effect on household bills will depend on how projects are funded and regulated, as well as the wider costs and benefits of the electricity network.

The policy also highlights a difficult balance for the Welsh Government. It wants to protect communities and the landscape while expanding the electricity network needed to support renewable energy, economic development and its net-zero ambitions.

An independent advisory group established to examine the future grid heard concerns from communities that the impact of overhead lines on the countryside, rural businesses and residents had not been given sufficient weight. Its report also recognised the need for stronger evidence on costs, technical options and the environmental effects of different approaches.

The government therefore faces pressure from communities seeking greater protection from large-scale infrastructure, while also needing to ensure that the electricity network can accommodate new generation and growing demand.

For North Wales, where renewable energy developments and proposed electricity connections have generated debate, the outcome could influence how some future projects are designed and assessed. It will not, by itself, settle the arguments over individual routes or guarantee that all new cables will be buried.

Mr Price said the government wanted infrastructure to be sensitively designed, minimising its effects on communities and the environment while delivering maximum benefits for Wales.

The consultation, published today, invites views on how the undergrounding-first approach should be implemented. Further details are available through the Welsh Government website.