A new interstate transmission system (ISTS) scheme associated with the upcoming South Kalamb substation in Maharashtra is in the making. The project will involve a mix of TBCB and RTM modalities.
Called “Network expansion scheme for drawl of power at South Kalamb substation,” the scheme will have three components – Part A, B and C. The biggest component, Part A, will be developed under the tariff-based competitive bidding (TBCB) framework while the remaining two parts will see the deployment of the regulated tariff mechanism (RTM) modality.
This scheme was cleared at the most recent meeting of National Committee on Transmission (NCT) and PFC Consulting Ltd has been nominated as the bid process coordinator (BPC) for the TBCB component – Part A – that is estimated to cost Rs.901 crore and has envisaged completion schedule of 24 months.
The primary objective of the scheme is to create a downstream system from the upcoming South Kalamb substation in Maharashtra, so as to help provide direct feed to Mumbai, apart from improving the available transfer capacity (ATC) of the area.
Part A aims at creating new bus sections — two of 765kV and two of 400kV – at the upcoming South Kalamb substation. Three interconnecting transformers (765/400kV, 1500 MVA) will also be put up at the said substation. Besides, three existing 400kV double-circuit lines, including Nagothane-Padghe, Pune-Navi Mumbai and Pune-Vikhroli, will be looped in and out at the South Kalamb substation.
Part B will involve reconductoring of a 1.7-km section of the 400kV Pune-Vikhroli line, while Part C entails upgrade of the 400kV bay at PGCIL’s Pune (AIS) substation, associated with the Pune-Vikhroli line.
Part B will be implemented by Western Transco Power Ltd, a subsidiary of Adani Energy Solutions Ltd, under RTM framework. Part C has been assigned to PGCIL, also under RTM. Parts B and C are small elements, together expected to cost Rs.16 crore, and with commissioning aligned to that of Part A.
Background
The South Kalamb substation (765/400kV, 2×1500 MVA) is being implemented by WRNES Talegaon Power Transmission, a TBCB subsidiary of Adani Energy Solutions Ltd. The project, with estimated completion date of January 2028, also involves LILO of the upcoming 765kV double-circuit line from Pune-III substation to Boisar-II substation. (See related T&D India story dated May 31, 2025.)
Besides, a new 6,000 MW, ±800kV HVDC terminal has been planned near South Kalamb that will transmit green energy from the Barmer-II substation in Rajasthan. (Read T&D India’s story “HVDC chosen over BESS for Rajasthan RE evacuation scheme” dated July 4, 2025). This TBCB scheme, for which bidding has yet to be initiated, is envisaged to complete only over the next five years or so.
Therefore, to expedite the transmission system downstream of South Kalamb, the present scheme “Network expansion scheme for drawl of power at South Kalamb substation” has been envisaged with a compressed time schedule of 24 months.
Technical consultant
PFCCL, very recently, initiated the technical consultant selection process for the TBCB component of the overall scheme, officially referred to as “Network expansion scheme for drawl of power at South Kalamb substation: Part A”
Featured photograph (source: Techno Electric & Engineering Co Ltd) is for representation only