Emma Fagan
Principal Engineer, Future Operations, EirGrid
Learn how the electricity transmission system operator for Ireland is overcoming the technical challenges of integrating more renewables, like wind and solar power, onto the grid to support the energy transition.
Renewable electricity will play a crucial role in Ireland’s energy transition. However, operating a power system with electricity generated by the wind or sun is technically very different from operating one based on fossil fuel-powered generation, presenting significant technical challenges. When you put more renewables on the system, you need to be able to manage potential instabilities.
Advancing renewable integration
Following the work of EirGrid with its Northern Ireland counterpart SONI — in collaboration with regulators and industry partners — up to 75% of Ireland’s electricity generation can now come from variable renewables, such as wind and solar, at any one time.
This is known as the system non-synchronous penetration (SNSP) limit, which is high in Ireland by international standards. To get to 75%, EirGrid did a series of system studies and operational trials to identify challenges and take required actions before making the change permanent.
As part of this process, it introduced new tools to the control centre, including a groundbreaking look-ahead security assessment tool. This allows operators in the control centre to run simulations every five minutes to understand how the electricity system will react to situations that might arise.
Up to 75% of Ireland’s electricity generation
can now come from variable renewables.
Enhancing grid stability
Another vital element protecting the electricity grid is the rate of change of frequency (RoCoF). Disturbances in the system can cause the frequency to change. The rate of this change is known as RoCoF.
Higher levels of renewables replacing conventional fossil fuel generation lead to reduced system inertia and potentially increased RoCoF. Each device on the system has a RoCoF setting; if that setting is exceeded, the device can ‘trip’ in sympathy, resulting in the disturbance propagating. This would be a system stability risk.
Therefore, a higher RoCoF limit was required prior to operating the power system with higher levels of renewables. Following a large decade-long programme in conjunction with the regulators, the distribution system operators and the generators on the island of Ireland, EirGrid brought up the RoCoF limit from 0.5 Hertz per second to 1 hertz per second.
Reaching 2030 targets
EirGrid is currently doing more system studies and assessments, aiming to start a trial later this year to bring its SNSP limit above 75%. Such efforts are ongoing to get the electricity system ready to take on more renewables, as the operator and its stakeholders work towards the 2030 targets and beyond.
EirGrid is responsible for operating, developing and enhancing the electricity grid and market. For more information, visit EirGrid.ie
