SECI Offers Over 7.3 GW of Renewable Energy for Sale Under Multiple ISTS Schemes

The Solar Energy Corporation of India (SECI) has published updated details on power capacities available for sale under multiple Inter-State Transmission System (ISTS) schemes as of July 15, 2025. These capacities span solar, solar plus storage, hybrid, firm dispatchable, and round-the-clock (RTC) renewable energy projects, awarded through competitive bidding. 

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Across all schemes, SECI’s trading margin of INR 0.07/kWh applies in addition to the discovered tariffs.

ISTS Tranche-XV (Solar + BESS)

This scheme includes a total capacity of 700 MW, combining solar generation with battery storage. JSW Neo Energy Limited has secured 500 MW, and ACME Solar Holding Limited has secured 200 MW, both at a discovered tariff of INR 3.42/kWh. Power from these projects is expected to be commissioned within 24 months from the effective date of the power purchase agreement (PPA). 

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A key feature of this scheme is the requirement to supply half of the contracted capacity during the peak evening hours between 18:00 and 24:00, for a two-hour duration. This makes the scheme particularly useful for discoms facing evening demand surges.

ISTS Tranche-XIV, XIII, and XI (Solar)

SECI has also made available 1,150 MW of standalone solar capacity through these three tranches. Under Tranche-XIV, Avaada Energy Private Ltd. and ReNew Solar Power Private Ltd. have each been awarded 300 MW at a competitive tariff of INR 2.57/kWh. In Tranche-XIII, NTPC Renewable Energy Ltd. has secured 250 MW, also at INR 2.57/kWh. 

Meanwhile, Eden Renewable Cadet Private Limited has been awarded 300 MW under Tranche-XI at INR 2.6/kWh. These projects are scheduled for commissioning within 18 to 24 months and are not governed by the Uniform Renewable Energy Tariff (URET) mechanism, offering more tariff flexibility to buying entities.

ISTS Manufacturing Linked Solar Power Scheme

This scheme offers the largest individual tranche, with a total of 2,466 MW linked to domestic manufacturing commitments. 

Azure Power India Pvt. Ltd. will supply 667 MW at a base tariff of INR 2.42/kWh, though the effective tariff rises to approximately INR 2.99/kWh after accounting for Basic Customs Duty (BCD) and Goods and Services Tax (GST). Adani Green Energy Four Limited will contribute the remaining 1,799 MW under this tranche. 

These projects are expected to be commissioned over a period of 24 to 60 months. They also benefit from regulatory waivers on ISTS transmission charges and losses, making them cost-effective for distribution companies over the long term.

ISTS Hybrid Tranche-IX and VIII

Combining solar and wind power, these hybrid tranches offer increased capacity availability throughout the day and night. Under Tranche-IX, Juniper Green Energy Private Limited, ACME Solar Holdings Limited, and Sembcorp Green Infra Private Limited are offering a combined capacity of 600 MW at tariffs ranging from INR 3.25 to 3.26/kWh. 

Tranche-VIII is significantly larger, offering 1,200 MW from six developers, including JSW Neo Energy Limited, Avada Energy Private Limited, and AMPIN Energy Utility Private Limited. Tariffs in this tranche range from INR 3.43 to 3.46/kWh. Both hybrid tranches are governed by the URET mechanism, which ensures a uniform approach to power procurement and tariff benchmarking.

ISTS Hybrid Tranche-VI (with BESS)

This scheme includes 600 MW of hybrid capacity with added battery energy storage, ensuring enhanced power reliability. 

Developers include AMP Energy Green Private Limited (50 MW at 52.06% CUF), ReNew Vikram Shakti Private Limited (300 MW at 72% CUF), Hero Solar Energy Private Limited (60 MW at 60.66% CUF), and ACME Cleantech Solutions Private Limited (190 MW at 60% CUF). The tariffs for these projects range from INR 4.64 to 4.72/kWh, reflecting the premium associated with storage-backed energy delivery.

ISTS FDRE-IV and FDRE-VI (Firm & Dispatchable Renewable Energy)

Focused on ensuring firm and dispatchable renewable power, the FDRE-IV scheme includes 630 MW distributed across five developers — Hexa Climate Solutions, JSW Neo Energy, Serentica Renewable, Vena Energy Aura, and Hero Solar Energy — with tariffs hovering around INR 4.98 to 4.99/kWh. 

Meanwhile, the FDRE-VI scheme is focused exclusively on peak hour supply from 18:00 to 24:00. Under this tranche, Altra Xergi Power Private Limited is offering 200 MW at a notably high tariff of INR 8.5/kWh. This premium pricing reflects the guaranteed supply during high-demand evening periods.

ISTS RTC-IV (Round-the-Clock Power)

SECI’s RTC-IV scheme offers 420 MW of round-the-clock renewable power, with supply commitments spread across Hero Solar Energy Private Limited, Hexa Climate Solutions Private Limited, Jindal India Power Private Limited, and Sembcorp Green Infra Private Limited. Tariffs in this tranche range from INR 5.06 to 5.07/kWh. 

The scheme comes with strict performance benchmarks — a minimum monthly dispatch fulfillment ratio (DFR) of 75 percent, an annual DFR of 80 percent, and a peak hour DFR of 90 percent. Non-compliance can attract penalties ranging from 1.5 to 1.75 times the cost of the shortfall, ensuring high reliability for purchasing utilities.

Read the SECI official document here.