CERC Proposes Amendments to Regulations on Sharing ISTS Charges and Losses

The proposed regulations will come into force after being notified by the Commission


The Central Electricity Regulatory Commission (CERC) has proposed amendments to the ‘Sharing of Interstate Transmission Charges and Losses) Regulations, 2020.’

Some of the important amendments are listed here.

Raising bills

The yearly transmission charges will be shared by drawee ISTS customers of the receiving region in proportion to their quantity of GNA. Previously, the yearly transmission charges were to be shared by drawee ISTS customers of the receiving region and designated ISTS customers with untied long-term access in the receiving region, in proportion to the quantity of LTA plus medium-term open access and untied LTA, respectively.


Per another important amendment, the ‘T-GNA rate (in ₹/MW/block) will be published for each billing month by the implementing agency, which will be calculated state-wise as: Transmission charges for GNA for entities located in the state, for the billing month, under the first bill X 1.10 / (number of days in a month X 96 X GNA quantity, in MW, for the corresponding billing period).

Earlier, the short-term open access rate (in paise/kWh) for each billing month was to be calculated as: Transmission charges of the state for the billing month/(7200 X the quantity, in MW, of long-term access plus medium-term open access of the state for the corresponding billing period).

The transmission charges for T-GNA will be payable by drawee entities located in the state, as per the last published T-GNA rate for the state. Per the previous clause, the transmission charges for short-term open access were to be paid by generating stations located in the state, as per the last published rate.

Transmission charges in case of delay

Another amendment states that when the commercial operation date of a connectivity grantee is delayed and the associated transmission system has achieved commercial operation, the connectivity grantee should pay yearly transmission charges corresponding to connectivity capacity which has not achieved commercial operation. Earlier, when the generating station’s operation was delayed and the associated transmission system had achieved commercial operation, it was required to pay transmission charges corresponding to the LTA granted to the generating station, which had not achieved commercial operation.

When only some of the transmission elements of the associated transmission system have achieved commercial operation before the operation of the associated transmission system, yearly transmission charges of such transmission elements will be included to determine the transmission charges of ISTS customers. Previously, if only some of the transmission elements achieved commercial operation and the generating station wanted part-operationalization of LTA, the central transmission utility could allow it. The yearly transmission charges were to be included for the determination of transmission charges of the ISTS customers.

Another amendment says that when connectivity is granted on existing margins and the commercial operation of such a grantee is delayed, it should, corresponding to the capacity delayed, pay transmission charges from the start date of connectivity at the rate of ₹3000 (~$38.37)/MW/month. Whereas the earlier clause noted that when long-term access is granted and the commercial operation date of the generating station is delayed, the generating station must pay transmission charges at 10% of the transmission charge per MW for the state where it is located, corresponding to the capacity that is delayed.

Also, when a transmission line has already been constructed by an ISTS licensee, the yearly transmission charges should be payable by the generating station to the ISTS licensee. Earlier, when a dedicated transmission line had already been constructed, the generating station’s yearly transmission charges were to be payable to the licensee from the commercial operation of the transmission line until the operationalization of the LTA of the generating station.

According to another amendment, regional entities generating stations drawing start-up power or drawing power during shutdown after the commercial operation or for renewable generating stations drawing power during non-generation hours should pay transmission charges for injection or drawal beyond its T-GNA at the transmission deviation rate. According to the clause before the amendment, generating stations drawing start-up power from ISTS had to pay transmission charges at the rate of the transmission deviation in the state where they were located.

CERC has stated that the implementing agency should, within 45 days of the notification of the amendments, publish the revised procedures for implementation of the provisions of this amendment after stakeholder consultation.

Last November, the Ministry of Power announced that ISTS charges would be levied on renewable energy projects, including solar, wind, pumped hydro storage, and projects with battery energy storage systems (BESS) commissioned after June 30, 2025.

In 2019, CERC issued a draft regulation for sharing interstate transmission charges and losses.

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