Using computer power and algorithms we have generated a visual impact assessment of the Green Gen Cymru Towy/Usk preferred pylon route. The map enables us to determine from where the proposed pylons are visible and how many are visible from that exact location. It takes into account trees and buildings for an accurate assessment.
The assessment was produced at 1m resolution — for every 1m² an assessment was made. Any location highlighted in red will have at least one visible pylon. The darker the red, the more pylons visible from that location.
The map assumes you can see a pylon at a 5km distance — a conservative figure; German studies suggest 10km visibility. It uses bare-earth terrain data (buildings and trees removed) at 1m resolution LiDAR from Welsh Government (2020). Pylons simulated every 250m along the preferred route centroid (388 pylons). Only the pylons themselves are assessed, not the transmission lines between them, so the map shows a conservative estimation of overall visual impact.
27m pylons simulated every 250m as per the Green GEN Cymru proposed preferred route. A Zone of Theoretical Visibility (ZTV) was assessed for each pylon using Welsh Government 1m LiDAR DSM, providing a 1m binary map of where each individual pylon is visible from. This approach copies that taken by development companies in the UK — but at higher resolution than most.