A major interstate transmission system (ISTS) scheme has recently been approved by the National Committee on Transmission (NCT) that will help transmit renewable energy to upcoming green hydrogen/green ammonia plants in Visakhapatnam, Andhra Pradesh.
Estimated to cost Rs.8,386 crore, this scheme will be developed under the tariff-based competitive bidding (TBCB) framework, with REC Power Development & Consultancy Ltd (RECPDCL) named as the bid process coordinator.
The scheme, with a gestation period of 30 months, has been formally termed as “Transmission system for proposed green hydrogen/green ammonia projects in Vizag area, Andhra Pradesh (Phase-I).”
As the estimated project cost exceeds Rs.500 crore, the scheme would require Union power ministry concurrence before the bidder selection process could begin. The ministry’s approval process is currently underway, it is learnt.
The proposed scheme seeks to meet 5,000 MW of green energy demand from upcoming green hydrogen/green ammonia projects in Vizag area.
It is further learnt that Central Transmission Utility of India Ltd (CTUIL) has already received an application from NTPC Green Energy Ltd (NGEL) seeking General Network Access – Renewable Energy (GNARE) to the tune of 2,500 MW for its upcoming green hydrogen plants in Visakhapatnam. NGEL expects connectivity to start from September 2028.
Project elements
The key project elements of this transmission scheme are two new substations in Andhra Pradesh – 4×1500 MVA, 765/400kV Pendurthi (Vizag) GIS substation and 3×1500 MVA, 765/400kV Khamman-II substation. These two substations will be interconnected via a 765kV double-circuit line running about 350 km.
Besides, ISTS connectivity to the proposed Pendurthi substation will be achieved by connecting it to the Srikakulam substation through a 765kV double-circuit line of about 200 km. Khamman-II will be linked to the existing Warangal (New) substation via a 765kV double-circuit line spanning around 100 km. Khammam-II will also be connected to the existing Khammam ISTS substation through a 400kV double-circuit line of about 20 km.
Power Grid Corporation of India Ltd (PGCIL) is the owner of the Srikakulam and Khamman substations, while Warangal (New) substation was commissioned through an ISTS-TBCB scheme housed under Warora Kurnool Transmission Ltd (WKTL). This was originally won by Essel Infraprojects Ltd but was later acquired by Adani Energy Solutions Ltd (AESL). The 765/400kV Warangal substation was commissioned in September 2023 after AESL acquired WKTL in March 2021.
Preliminary estimates suggest that this transmission scheme will involve creation of around 1,380 ckm of transmission lines and 10,500 MVA of substation capacity, all within Andhra Pradesh.
Data centre loads
The Pendurthi (Vizag) GIS substation will also help in meeting data centre load demand at Pendurthi. As data centres would need reliable power supply, ISTS connectivity has been proposed. This would be achieved by a LILO (of around 20 km) of the existing 400kV double-circuit Kalpakka – Maradam (quad) line, at the upcoming Pendurthi substation. The said line is part of the intrastate grid and is owned by state utility Transmission Corporation of Andhra Pradesh Ltd (APTRANSCO).
Green hydrogen scheme for Kakinada
Speaking of transmitting RE power for upcoming green hydrogen/green ammonia plants in Andhra Pradesh as a whole, an ISTS-TBCB scheme catering to Kakinada – where total demand is estimated at 6,000 MW — is already under bidding. Termed as “Transmission system for proposed green hydrogen/green ammonia projects in Kakinada area (Phase-I),” it is housed under project SPV “Kakinada I Transmission Ltd.” Going by the latest available schedule, the last date of submission of technical and financial bids is October 9, 2025, this being at least the ninth extension of bid submission date from the original May 6, 2025.
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