Latest official statistics suggest that nine interstate transmission system (ISTS) schemes, awarded under the tariff-based competitive bidding (TBCB) route, were fully commissioned during the fiscal year ending March 31, 2025.
While Power Grid Corporation of India Ltd (PGCIL) accounted for five of these nine schemes, Resonia (formerly Sterlite Power) commissioned two. Renew Transmission Ventures and Adani Energy Solutions Ltd (AESL) had one each.
The aggregate capital outlay of these nine ISTS-TBCB schemes was around Rs.8,800 crore, and collectively these schemes will earn annual transmission charges (tariff) of an estimated Rs.856 crore.
According to estimates made by T&D India, the total infrastructure created by these nine schemes is around 3,165 ckm of transmission lines and 7,820 MVA of substation capacity.
It may be noted that not all of this infrastructure was necessarily commissioned in FY25. It is likely that some elements of these nine schemes could have commissioned prior to FY25 even if the schemes were fully commissioned in FY25.
The five schemes commissioned by PGCIL included three schemes related to RE evacuation from Rajasthan. These three schemes saw a time overrun of more than two years as project execution was hampered by issues relating to potential GIB (Great India Bustard) habitats.
The most complex scheme to have fully commissioned in FY25 was “Mumbai Urja Marg Ltd,” owned by Resonia. Called “Western Region System Strengthening XIX and North Eastern Region System Strengthening IX,” this ISTS-TBCB scheme awarded in June 2020 had a geographical footprint covering northeastern states of Assam and Arunachal Pradesh, as well as western region states Maharashtra and Gujarat. This scheme is significant as it would help transmit over 2,000 MW of green power to Mumbai and Navi Mumbai.
Adani Energy Solutions Ltd (AESL) commissioned its lone ISTS-TBCB project in March 2025. Housed under TBCB subsidiary “Khavda II-A Transmission Ltd,” this scheme, located in Gujarat, mainly involved setting up the 765kV double-circuit line of 355 ckm from Khadva Pooling Station-2 (KPS) to Lakadia pooling station. Aimed at RE evacuation from the Khavda region in Gujarat, this scheme was commissioned without time overrun.
Here is a summary of the nine schemes ISTS-TBCB schemes fully commissioned in FY25
Project SPV: Powergrid Bhadla Transmission Ltd
Developer: PGCIL
Scheme: Transmission system strengthening scheme for evacuation of power from solar energy zones in Rajasthan (8.1 GW) under Phase-II, Part B
Project SPV: Powergrid Sikar Transmission Ltd
Developer: PGCIL
Scheme: Transmission system strengthening scheme for evacuation of power from solar energy zones in Rajasthan (8.1 GW) under Phase-II, Part C
Project SPV: Powergrid Aligarh Sikar Transmission Ltd
Developer: PGCIL
Scheme: Transmission system strengthening scheme for evacuation of power from solar energy zones in Rajasthan (8.1 GW) under Phase-II, Part D
Project SPV: Powergrid Dharamjaigarh Transmission Ltd
Developer: PGCIL
Scheme: WRES XXVIII and WRES XIX
Project SPV: Powergrid Raipur Pool Dhamtari Transmission Ltd
Developer: PGCIL
Scheme: WRES XXVII
Project SPV: Gadag Transmission Ltd
Developer: ReNew Transmission Ventures
Scheme: Transmission system for Gadag Solar Energy Zone (1,000 mw), Karnataka, Part A, Phase I
Project SPV: Mumbai Urja Marg Ltd
Developer: Resonia
Scheme: WRSS XIX and NERSS IX
Project SPV: Nangalbibra-Bongaigaon Transmission Ltd
Developer: Resonia
Scheme: New 220/132kV substation at Nangalbibra
Project SPV: Khavda II-A Transmission Ltd
Developer: Adani Energy Solutions Ltd
Scheme: Transmission system for evacuation of 4.5 GW RE injection at Khavda PS Under Phase II, Part A
ISTS-TBCB schemes under construction
As of March 31, 2025, an estimated 85 ISTS-TBCB schemes were under construction. Of these, as described in T&D India’s special story dated April 8, 2025, as many as 45 were awarded in FY25 alone.
Featured photograph is for representation only
