North Connacht 110 kV Project/EirGrid Capital Project 0816

Small-scale grid infrastructure is being proposed for North Connacht after a review of the region’s renewable energy plans.

EirGrid is legally obliged to connect those who generate electricity. This means we must develop the grid in response to plans for new electricity generation, such as wind farms. There is a large amount of electricity generated by wind farms in North Connacht and there is more planned over the coming years.

The level of renewable generation is greater than the capacity of the local electricity network. This means we have to look at ways at improving the electricity infrastructure in the region.

Original and new proposal

Our original proposal was the Grid West project, a large scale development based on 400kV technology. However, by June 2017 the amount of planned renewable generation capacity in the region had dropped by half and Grid West was no longer required.

EirGrid announced in September 2017 that the large-scale Grid West project was no longer needed. We anticipated then that the reduced amount of renewable energy generated could be met through a smaller 110 kV development. That remains the case and we are now bringing forward the North Connacht 110 kV project.

What is the possible route and technology for this new project?

The project will be either a 110 kV overhead line or an underground cable. If an overhead line is used the majority of the line will be carried on timber twin pole sets, with steel angle masts where required, which is no different to the existing national electricity infrastructure which measures in the region of 5,000km. The start point for the North Connacht 110 kV project will be at Moy substation near Ballina, Co. Mayo. The end point will be at Tonroe substation near Ballaghaderreen, Co. Roscommon. There will also be 32km of upgrade works on the existing line from Tonroe to Flagford (Carrick-on-Shannon).

The development is at Step 4 of our six-step approach to developing the grid and consulting with stakeholders. This process is detailed in our Have Your Say publication. The first two steps identified the need for the project and a number of possible technology options while step three involved selecting the best performing technology options.

Why is this project needed?

Ireland has a target for renewable generation to account for 40% of electricity consumption by 2020. This includes wind, wave and tidal power.

Although there has been a reduction in anticipated wind generation in North Connacht, there is still a need to connect generators in there. This can now be met through the development of 110 kV electricity infrastructure; not the 220 kV nor 400 kV infrastructure that was proposed under Grid West.

As the national electricity transmission system operator for Ireland, we have a statutory function to connect electricity generators. Subject to direction from the regulator, this statute requires us to offer a connection to the grid for those who request it. When an electricity generator accepts our connection offer, we have to meet their needs. This means we are legally required to develop the grid in response to plans for new electricity generation, such as wind farms.

What are the benefits of this project?

By connecting renewable energy from the North West to the grid, this new project will reinforce the electricity network, supporting Mayo County Council’s aim to enhance the attractiveness of the county as a place in which to live, work and invest.