The Solar Energy Corporation of India (SECI), under the Ministry of New and Renewable Energy (MNRE), has launched a significant tender inviting bids for 1.2 GW of interstate transmission system (ISTS)-connected solar power projects, integrated with 600 MW / 3,600 MWh of energy storage systems (ESS). The projects will be developed on a build-own-operate (BOO) basis.
SECI will enter into 25-year power purchase agreements (PPAs) with successful bidders for the procurement of power. The generated electricity will be sold to various buying utilities across India through a back-to-back PPA-PSA structure, with SECI acting as the intermediary nodal agency.
Tender Scope and Capacity
According to the Request for Selection (RfS) document, developers must bid for a minimum capacity of 50 MW and can go up to 600 MW, in multiples of 10 MW. For every 1 MW of contracted solar capacity, developers are required to integrate at least 0.5 MW / 3 MWh of energy storage.
The storage system must be co-located with the solar project. If the solar project is spread across multiple locations, the ESS must be co-located with at least one component of the project. Developers have the liberty to choose project sites at their own discretion and bear the responsibility of land acquisition, connectivity, and other related logistics.
Important Dates
- RfS Issued: June 19, 2025
- Pre-bid Meeting: Expected in early July
- Last Date for Online Bid Submission: August 18, 2025
- Last Date for Offline Submission: August 20, 2025
- Bid Opening Date: August 21, 2025
Financial & Eligibility Requirements
- Earnest Money Deposit (EMD): ₹15.93 lakh per MW
- Performance Bank Guarantee (PBG): ₹39.82 lakh per MW
- Processing Fee: ₹20,000/MW (capped at ₹20 lakh) + 18% GST
- RFS Document Fee: ₹50,000 + GST
- Minimum Net Worth: ₹16 lakh per MW
- Minimum Annual Turnover: ₹9.15 lakh per MW
The projects must be commissioned within 24 months from the effective date of the PPA, with a grace period of 6 months.
Domestic Content & Manufacturing
All solar modules and cells used in the projects must be sourced from manufacturers listed in the MNRE’s Approved List of Models and Manufacturers (ALMM), ensuring support for domestic manufacturing under India’s self-reliance initiative.
Strategic Importance
This tender is a step toward India’s broader vision of achieving 24×7 clean, dispatchable power and bolstering grid reliability through large-scale energy storage integration. The solar-plus-storage model supports load balancing, peak demand management, and smoother renewable energy penetration into the grid.
The latest tender under SECI’s ISTS Tranche XXI follows earlier large-scale renewable storage bids and is part of the government’s effort to attract serious developers to invest in next-gen utility-scale solar and battery storage infrastructure.
For detailed documents, eligibility criteria, and submission formats, bidders can access the full tender on SECI’s official portal.
| Capacity | 1,200 MW Solar + 600 MW / 3,600 MWh Storage |
| Location | Pan-India (project sites chosen by the developer; ISTS-connected) |
| Last Date | 18/08/2025 |
| Results | To be announced after bid opening on August 21, 2025 |
