Power Grid Corporation of India Ltd (POWERGRID) has received the Letter of Intent (LoI) for the development of an Inter-State Transmission System (ISTS) at Tumkur-II, Karnataka. The project is designed to integrate 2.7 GW of renewable energy (RE) potential, supporting India’s national target of 500 GW of non-fossil fuel capacity by 2030. The LoI was dated March 30, 2026, and officially received by the corporation on April 1, 2026.
Project Evolution and Regulatory Context
The transmission scheme underwent significant expansion during its administrative trajectory. Originally designed to integrate 1.5 GW of RE potential, the scope was increased to 2.7 GW following the Ministry of New and Renewable Energy’s (MNRE) identification of additional potential in June and August 2025.
The technical requirements were finalized across multiple regulatory venues. The 31st and 33rd meetings of the National Committee on Transmission (NCT) recommended the augmentation to address the volume of connectivity applications in the Southern Region. This alignment was further ratified during the 39th meeting of the Consultation Meeting on Evolving Transmission Schemes in the Southern Region (CMETS-SR).
Auction Results and Bidding Process
PFC Consulting Limited (PFCCL) served as the Bid Process Coordinator (BPC) for the project, as established in the Transmission Service Agreement (TSA). The tender was issued on November 19, 2025, and conducted via the Tariff-Based Competitive Bidding (TBCB) methodology. Technical bids were opened on March 11, 2026.
Five bidders qualified for the Initial Offer stage of the competition:
- Power Grid Corporation of India Ltd
- Adani Energy Solutions Ltd
- Resonia Ltd
- Dilip Buildcon Ltd
- G R Infraprojects Ltd
Technical Specifications and Infrastructure Scope
The infrastructure involves significant augmentation of the Tumkur-II Pooling Station (PS) and the establishment of high-capacity grid connectivity to the Madhugiri substation.
| Component | Specification Details | Function |
| Interconnecting Transformers (Set 1) | Three 400/220kV, 500 MVA units (5th to 7th transformers) | Primary capacity augmentation for RE integration. |
| Interconnecting Transformers (Set 2) | Three 400/220kV, 500 MVA units (8th to 10th transformers) | Secondary capacity augmentation for 2.7 GW total potential. |
| Transmission Line | 400kV quad double-circuit line (~100 km) | Main trunk for high-capacity power evacuation. |
| Route | Tumkur-II PS to Madhugiri substation | Interconnects the RE pooling station with the existing grid node. |
| 400 kV Line Bays (Madhugiri) | Two 400 kV line bays | Provided by POWERGRID at no cost to the SPV; available via Narendra New–Madhugiri upgrade. |
| Voltage Regulation | ±300 MVAr Static Synchronous Compensator (STATCOM) | Includes switching arrangement for two under-implementation 125 MVAr bus reactors. |
| Evacuation Infrastructure | Six additional 220 kV line bays | Dedicated termination points for independent renewable energy developers. |
Contractual Framework and Corporate Structure
The project is structured on a Build, Own, Operate and Transfer (BOOT) basis. Execution is managed through a Special Purpose Vehicle (SPV) designated as “Tumkur II RE Transmission Limited.” Ownership of the SPV transitions from the BPC to POWERGRID following the bidding conclusion. The ISTS license is subject to approval by the Central Electricity Regulatory Commission (CERC), and the TSP is required to maintain the assets for the duration of the contract.
Implementation Timeline and Investment Context
The estimated project outlay is Rs. 1,051 crore, as reported in the investment context provided by T&D India. The implementation timeframe is 24 months from the effective date. In accordance with standard ISTS protocols, the system must achieve an operational life of 35 years from the Commercial Operation Date (COD). Upon completion of this term, project assets will be transferred to the Central Transmission Utility (CTU) or a government-designated agency at zero cost.
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