Ireland’s Grid Flexibility Assessment Shows Why Location Matters

Ireland's electricity regulator released its first national assessment of grid flexibility needs, identifying 234 MW and 58 GWh of potential upward flexibility requirements on distribution networks by 2028. The Commission for Regulation of Utilities found that batteries, managed electric vehicle charging, and industrial demand response could all contribute to meeting these needs.

The assessment examined specific locations to show why geography matters. At the Naas 38 kV/10 kV substation, modeled requirements reach 0.6 MW and 3 MWh in 2028, concentrated in January. Planned reinforcement by 2030 eliminates the flexibility requirement at that location. However, the assessment does not represent a commitment to purchase flexibility services or install equipment.

A battery located elsewhere in Ireland could provide balancing services and help integrate renewable generation while providing no relief to the Naas constraint. The electrical connection determines effectiveness. A resource must change power flows across the affected equipment in the required direction during periods when that equipment is constrained.

The same principle applies to demand response. A large fleet of electric vehicles represents flexible demand nationally, but only vehicles connected to electrically useful locations can relieve a particular transformer. Their charging must also be adjustable without compromising required journeys.

Timing presents another challenge. The 0.6 MW and 3 MWh figures at Naas describe different aspects of the requirement. The duration of individual events, recovery time between them, and customer operating requirements all affect which resources could address the need. A battery discharging for five hours does not necessarily match the actual constraint profile.

In Britain, UK Power Networks stopped seeking flexibility tenders for certain single-transformer substations where constraints typically lasted 24 hours. The available flexibility market could not address those requirements effectively on technical and commercial grounds. In those circumstances, reinforcement may prove more appropriate than pursuing flexibility solutions.