Approval of SONI’s proposal to establish guidelines on electricity transmission system operation (SOGL).

26 March 2021

This update is intended for stakeholders affected by European Network Codes.

Article 145 of the electricity transmission system operation (SOGL) states, that the Transmission System Operator’s (TSO) of NI/IE synchronous areas (SONI and Eirgrid) may submit a proposal to their competent regulatory authorities (RAs) requesting not to implement an automatic Frequency Restoration Process (aFRP). This proposal should include a cost-benefit analysis demonstrating that implementation of an aFRP would lead to higher costs than benefits.

aFRP is a process that is enabled by the use of an AGC system (Automatic Generation Control) which is a machine to machine set point system that does not require manual dispatch instructions from control centres.

In September 2019, the TSOs made their initial submission. The RAs reviewed the proposal and considered that the cost-benefit analysis on the initial submission needed more detail to conclude the need to reject the implementation of an aFRP in the NI/IE synchronous area.

After various discussions between the TSOs and RAs, the TSOs submitted a supplementary note. The RAs were satisfied that the information provided in the supplementary note clearly displayed a thorough cost-benefit analysis on the impact of implementation of an aFRP in the NI/IE synchronous area and agreed with the conclusion of the assessment.

In accordance with Article 145(2) of SOGL the TSOs and RAs are required to re-evaluate this decision at least every four years. We note that the next evaluation on the implementation of aFRP may need to be carried out sooner than four years in order to capture and evaluate the impact that any new interconnector may have on the current SEM market arrangements and to be able to effectively reflect this in other work streams as required. Therefore, the RAs intend to commence work with the TSOs on the review of aFRP in April 2023.

aFRP Approval Letter