Reforming Unscheduled Deviations in the GCC Power Grid : A Transition to a 15-Minute Net Deviation Regime

While these technologies support decarbonization goals, their variability and limited controllability introduce new operational challenges, particularly in managing real-time imbalances across Member States. Besides, Member States TSO balance the excess imports / exports in the same dispatch period to avoid financial implication, resulting in tie lines deviations from schedule. The current framework for Unscheduled Deviations (UD), based on a 60-minute net calculation, seems inadequate in capturing short-term fluctuations and providing fair incentives for system discipline. This limitation becomes more critical as renewable penetration increases, amplifying intra-hour variability and forecast errors.

To address these shortcomings, GCCIA initiated a comprehensive review of the UD mechanism, exploring alternative approaches aligned with international best practices. Two options were considered: adopting a gross deviation methodology or transitioning to a shorter dispatch interval. While both approaches demonstrated potential benefits, the analysis concluded that reducing the dispatch period from 60 minutes to 15 minutes offers the most practical and immediately implementable solution. This method enhances granularity, reduces 1 the masking effect of intra-hour self-compensation, and aligns with practices in advanced power markets such as ENTSO-E and PJM.

Building on this decision, a full-scale assessment of the 15-minute UD calculation was implemented in 2024, followed by a preliminary assessment for Q1-Q3, 2025. The results confirm that the revised framework significantly improves the accuracy of imbalance detection and fairness in cost allocation and compensation to the supporting Member State. Sensitivity analyses on various threshold levels (6.25 MWh, 12.5 MWh, 13.5MWh, 15MWh 25 MWh) reveal that intermediate thresholds, particularly 12.5 MWh, strike an optimal balance between responsiveness and financial sustainability. Furthermore, the strategic use of Emergency

Declarations (EDs), which allow Member States to exempt specific periods from UD charges, emerged as a critical lever for mitigating financial exposure. Simulations and analysis show that utilizing the increased annual cap on EDs from 18 to 72 under the new regime can substantially reduce costs without compromising system reliability.

The transition to a 15-minute dispatch period requires targeted operational and regulatory enhancements, including upgrades to forecasting and scheduling tools, adaptation of settlement systems, and amendments to the Power Exchange and Trading Agreement (PETA) and

Interconnector Transmission Code (ITC). These changes are incremental rather than disruptive, making the proposed reform both feasible and cost-effective.

In conclusion, the adoption of the 15-minute net UD mechanism, combined with optimized thresholds of 12.5 MWH and expanded flexibility for emergency declarations, represents a decisive step toward modernizing the GCC power system. This evolution strengthens reliability, supports renewable integration, and ensures a fair and transparent framework for cross-border operations. The findings presented in this paper provide a clear roadmap for implementation, reinforcing GCCIA’s commitment to building a resilient and efficient regional electricity market.