Eden-Carnmoney Project

The Project

SONI is the electricity transmission system operator for Northern Ireland. This means we plan for the future of the electricity grid and operate it every minute of every day. We ensure that everyone has power when they need it at the most economical price possible.

To prepare for a clean energy future, SONI must make the electricity grid stronger and more flexible. The grid will need to carry more power, and most of this power will come from renewable generation that varies depending on the weather.

What will the project involve?

The Eden – Carnmoney project is a high-capacity transmission system upgrade between Eden 110 kV Substation, near Carrickfergus, and Carnmoney 110 kV Substation in South Antrim, on the outskirts of North Belfast. The electricity infrastructure which supplies Carrickfergus and Newtownabbey is now around 80 years old. To meet the growing needs of residents and businesses in the local area, a significant upgrade of electricity infrastructure is necessary. This is the purpose of the Eden – Carnmoney project.

  • New sections of underground cable from Eden Substation to west of Carrickfergus
  • Refurbishment of the existing 110 kV overhead line from west of Carrickfergus to Mossley
  • New high-capacity underground cable from Mossley to Carnmoney Substation
  • The de-energising and future removal of sections existing OHL circuit, as it currently runs between urban areas between Mossley and Carnmoney, and from Eden to west of Carrickfergus
  • A new transformer at Glengormley Main 110 kV Substation

What are the benefits of this project?


  • Security of supply - This project will build a more resilient and reliable grid, making sure that everyone has power when and where they need it.
  • Supporting growth - These improvements will support future investment and economic growth – aligning with the vision of the Belfast Region City Deal.
  • Helping to deliver climate change targets and decarbonising the power system for future generations. It is projected that Northern Ireland will require at least another 1,300 MW of electricity from clean sources, to meet the legally binding target of generating 80 percent of our electricity to be generated from renewable sources by 2030. This power will have to be generated, connected to the grid, and delivered throughout Northern Ireland. The Eden – Carnmoney project allows more clean energy to be used on the network. This project also aligns with the Northern Ireland Energy Strategy’s Path to Net Zero Energy’, as it will allow greater use of electricity for heating and transport, one of the strategy’s key ambitions.

  • Enabling removal of existing overhead line (OHL) circuit in some areas. By opting to underground the aspect of the project in and around urban hubs such as Carrickfergus and Carnmoney, this will allow NIE Networks to de-energise and at a later stage to remove the overground infrastructure in these areas. Due to development in the years since the original construction of the overhead line, some towers have become effectively landlocked, making them difficult to maintain and refurbish.