Answer from Hansard

The Secretary of State for Wales (Jo Stevens)

Overhead lines are much cheaper to build; according to the Institution of Engineering and Technology, undergrounding costs an estimated four and a half times more than overhead lines. Overhead lines are also quicker to build, cause less environmental damage, and are much easier to maintain. The cost of building this infrastructure is borne by electricity bill payers, and Plaid’s policy on undergrounding will not only increase bills, but suffocate the economic potential of Wales’s green industrial revolution.