The Ministry of Power (MoP) has announced that the inter-state transmission system (ISTS) charges waiver will be extended until 30 June 2025 for solar and wind energy projects that have been completed. The waiver only applies to ISTS charges, not losses, and the order takes effect right away. MoP waived ISTS charges and losses on all solar and wind projects completed before 30 June 2023 in August 2020. Pumped hydro storage projects and battery energy storage systems (BESS) that are completed by 30 June 2025 are also eligible for the waiver, provided they meet the requirements. According to the terms, solar and or wind power must meet at least 70% of the annual electricity requirement for pumping water in the pumped hydropower project. The ISTS charges for power generated by pumped hydro and BESS would be levied gradually, i.e., 25% of short-term open access (STOA) charges for the first five years of operation and gradually increasing by 25% every third year until reaching 100% of STOA charges in the 12th year. For two years, until 30 June 2023 and ISTS waiver would be allowed for trading electricity generated and supplied by solar, wind, pumped hydro, and BESS in the green term ahead market (GTAM); MoP will review this arrangement on an annual basis, depending on the future development of the power market. The ISTS used for electricity transmission across the territory of an intervening state, as well as transmission of electricity within the state that lies on the path of interstate transmission, would be included for the purpose of sharing ISTS charges. Any ISTS charge waiver that applies to inter-state transmission would apply to intra-state transmission as well. The Central Transmission Utility would then reimburse the transmission charges of such intra-state transmission systems. Any charge waiver granted by the ISTS for interstate transmission would also apply to intrastate transmission. The transmission charges of such intra-state transmission systems would then be reimbursed by the Central Transmission Utility. Image Source Also read: Karnataka proposes setting up a 500 MW ISTS-connected solar park