Effective Utilization of GNA Margin during Real Time Scheduling of Power

A new regime of inter-state transmission system (ISTS) planning, allocation of transmission system corridor access, contracting and scheduling of power by buyers including state DISCOMs from sellers and generating stations has been introduced through the implementation of General Network Access (GNA) and Temporary General Network Access (T-GNA) in Indian Power system. These new mechanisms to grant access to ISTS transmission system replaced the old methodologies of transmission planning, corridor allocation and scheduling of power through Long Term Access (LTA), Medium Term Open Access (MTOA) and Short-Term Open Access (STOA). This paper discusses shortcomings of the previous regime and highlights benefits of the new regime. The paper also provides an in-depth analysis of utilization of available GNA margin in real time by a sample state DISCOM in Eastern Region of India. The analysis has been done considering peak hours or the high demand hours of a day for a period of three months when the demand is higher compared to other months of the year. It has been observed through this analysis that there is a scope of effective utilization of real time GNA margin i.e. the quantum of power that can be scheduled by the state DISCOMs under approved GNA quantum in real time over and above the day ahead GNA schedules. The financial benefits in doing so have also been touched upon in the paper.