Proposed upgrade of south Mayo electricity line

PLANS are in the pipeline for a signifcant upgrade of an electricity line in south Mayo.

EirGrid PLC has applied for planning permission for works to uprate the existing Cashla - Dalton 110 kV overhead line (OHL), which straddles Mayo and Galway.

Within Mayo, the proposed development will take place in the following townlands: Dalgan Demesne, Pollbaun, Carrowbeg West, Gorteens, Seefin, Brookhill, Carrowmore, Ballyhankeen, Rushbrook East, Ballycusheen, Scardaun West, Millbrook, Milford Demesne, Curraghadooey, Lisduff, Rathgranagher (Miller), Drummin West, Carrowbeg East, Rathgranagher (Lindsay), Crossboyne, Kilbeg-Malone, Davros, Derry, Clare, Greaghans, Coolroe, Roos and Leedaun.

The OHL circuit is 57.7 km long, with 271 supporting structures. Some 24.7 km of the existing circuit is in Mayo, with 33k in Galway. Separate planning applications will be lodged with Galway County Council in respect of that portion.

The proposed works include replacing the existing OHL circuit conductor wires with a new higher capacity conductor, the replacement of angle masts in-situ at six locations with similar structures, as well as strengthening towers and their foundations, along with the replacement of polesets at 83 locations, with similar structures.

Documentation submitted to council planners sets out how the current electricity network in the west does not have the required capacity to accommodate the anticipated future electrical generation and maintain compliance with the Transmission System Security and Planning Standards (TSSPS). This project is part of a suite of OHL thermal uprates being progressed in the west to accommodate the expected future renewable generation, alleviate some of the constraints on existing generation in the area and to maintain compliance with the TSSPS.

The primary purpose of the thermal uprate works on this line is to alleviate overloading and provide additional network capacity on the circuit.