Drumnakelly - Tamnamore Upgrade

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 existing 110 kV network between Tamnamore and Drumnakelly is heavily congested, and the current capacity of the circuits are insufficient. Therefore, there is a need to upgrade current infrastructure to increase capacity.

SONI’s preliminary preferred option will replace existing circuits with a higher capacity conductor and uprate both overhead lines to 200MVA.


What are the benefits of this project?

The project will:

  • Increase the amount of clean energy we can transport from the North and West into urban centres in the East

To date approximately 1600 MW of renewable generation in Northern Ireland (including small scale generation) has been connected. Most of this is in the form of wind generation located in the North and West, while most demand for electricity is in the urban centres of the East.

  • Reduce congestion on the transmission grid and costly constraints

The Drumnakelly – Tamnamore 110kV reinforcement will reduce bottlenecks on the grid, expected to save consumers an estimated £3.69 million per year by 2030. The system between Drumnakelly and Tamnamore has become a point of congestion due to the level of generation in the West that passes towards the East. This means we cannot readily transfer all the clean energy that is available leading to cost implications for consumers.

  • Strengthen the network and ensure consistent security of supply

The Drumnakelly – Tamnamore 110kV reinforcement will help to improve the efficiency of the electricity system, ensuring a more efficient and secure electricity supply on a sustainable basis.

  • Support NI renewable energy targets & decarbonise the power system for future generations

We project that Northern Ireland will need at least double the amount electricity from clean sources, in order to meet our climate targets for 2030. This power will have to be generated, connected to the grid, and delivered throughout Northern Ireland.