SECI Opens 50 MW/100 MWh Standalone Energy Storage Tender for Short-Term Grid Support

SECI opens a new short-term procurement route for operational storage

Solar Energy Corporation of India Limited has opened a new Request for Selection for the utilization of 100 MWh of standalone energy storage, configured as 50 MW for two hours. The tender was published on 28 August 2026 under reference SECI/C&P/IPP/15/0008/26-27 and will be awarded through tariff-based competitive bidding followed by an electronic reverse auction. Unlike many storage tenders that ask a developer to build a new plant, this procurement is designed for storage that is already commissioned and commercially operational by the bid-submission deadline.

The RfS requires participating projects to have already been commissioned and to have declared their Commercial Operation Date by the bid-submission deadline. That distinction makes the tender commercially interesting. SECI is effectively seeking access to existing storage capacity for short-term, on-demand use rather than committing to a new multi-decade project. The RfS says the selected Energy Storage System Developer will own, operate and maintain the asset, while SECI will schedule charging and discharging according to the Energy Storage Purchase Agreement. The storage must be connected to the interstate transmission system so that SECI can charge and discharge the contracted capacity through the grid.

SECI published the tender on 28 August 2026. The pre-bid meeting is scheduled for 8 September 2026, while online bid submission closes on 30 September 2026 at 18:00 IST. Offline bid documents are due by 5 October 2026 at 18:00 IST, with bids scheduled to open on 6 October 2026.

How the 50 MW/100 MWh configuration will work

The project is specified as 50 MW/100 MWh. The 50 MW figure represents the maximum active power that can be charged or discharged at the delivery point, while 100 MWh is the dispatchable energy capacity. In practical terms, the specification corresponds to a two-hour system at full rated power. SECI states that for a complete cycle it may schedule discharge of up to 100 MWh and will provide charging energy equal to the discharged energy plus expected conversion losses.

The RfS illustrates the efficiency effect using an 85% round-trip efficiency. At that level, approximately 117.65 MWh would have to be supplied for charging in order to receive 100 MWh on discharge. This is why efficiency has a direct commercial effect: a lower-efficiency system consumes more charging energy for the same delivered output. SECI therefore requires the developer to guarantee at least 85% AC-to-AC round-trip efficiency on a monthly basis and provides for liquidated damages when actual performance falls below the required level.

Availability and cycling place performance at the centre

The tender requires a minimum system availability of 95% during the agreement term. Availability is defined around the ability of the storage system to charge or discharge when called upon according to SECI’s schedule. The developer must declare availability on a day-ahead basis for each grid time block. If contracted capacity is not available, the RfS provides for damages linked to the capacity charge, creating a direct incentive to maintain battery, power-conversion, control and auxiliary systems in operating condition.

The storage must also be capable of at least one complete operational cycle per day and up to two cycles per day, subject to a maximum of 485 cycles during the contract. Cycling limits matter because battery degradation is influenced by charge-discharge throughput, depth of discharge, temperature and state-of-charge management. For a developer, the one-year contract therefore becomes an optimization problem involving availability, efficiency, degradation, maintenance windows and the value of the monthly capacity payment.

The tender is technology-agnostic

SECI has not restricted the procurement to one battery chemistry. The RfS describes the opportunity as technology-agnostic as long as the selected Energy Storage System meets the required definition, performance criteria and safety requirements. This creates room for different storage technologies to compete on delivered performance rather than on a prescribed chemistry or equipment architecture.

For battery-based projects, however, the practical engineering requirements remain demanding. A grid-scale BESS must coordinate battery racks, Battery Management Systems, Power Conversion Systems, Energy Management Systems, thermal management, fire detection and suppression, transformers, protection systems, metering and SCADA. Because this tender uses an operating asset, bidders will also need confidence that the existing plant can meet the specified efficiency and availability through the entire contract period without compromising obligations to other customers or markets.

A one-year contract creates a different storage business model

The Energy Storage Purchase Agreement is scheduled to run from 1 November 2026 to 31 October 2027. That is much shorter than the long-term storage-service agreements commonly associated with newly built BESS projects. The selection will be based on the monthly capacity charge quoted in rupees per MW per month, meaning bidders are effectively competing on the price of making flexible storage capacity available to SECI for the contract term.

This approach can be important as India’s storage fleet expands. An operational battery may have periods when part of its capacity is not committed under another contract. Short-term procurement can create an additional route to monetize such availability. More broadly, operational storage assets could potentially combine several revenue streams, including capacity payments, peak shifting, ancillary services, market arbitrage and renewable-energy firming, subject to applicable regulations and contractual restrictions. A more flexible commercial framework can improve utilization of expensive storage infrastructure.

Why the tender matters for India’s renewable grid

India’s power system is adding large quantities of solar and wind, both of which vary with weather and time of day. SECI’s RfS explicitly links the growing need for energy storage with balancing support, peak-demand management, energy shifting and operational flexibility. These services become more valuable when solar output falls in the evening but electricity demand remains high, or when grid operators need a resource that can respond quickly to changing system conditions.

The 100 MWh procurement is modest beside India’s multi-gigawatt-hour storage pipeline, but its structure is significant. It treats energy storage as a service that can be contracted for a defined period instead of only as equipment embedded in a renewable project. If the model attracts competitive bids and operates successfully, it could provide a useful commercial reference for future short-term storage products and for a market in which batteries are dispatched according to system value rather than tied to a single generation plant.

Conclusion

SECI’s latest tender demonstrates that the next stage of India’s BESS market will involve commercial design as much as battery deployment. The selected project must already be operating, achieve 95% availability, maintain at least 85% monthly round-trip efficiency and support controlled cycling under SECI’s schedule. The upcoming bid process will show how developers price a one-year commitment of existing storage capacity. The result could help define how standalone batteries participate in a more flexible, renewable-heavy Indian grid.

SEO publishing details

Original documents and references

Source 1: Official SECI tender page

Source details: Primary procurement page confirming the 50 MW/100 MWh capacity, tender reference, publication date, bidding schedule and downloadable tender documents.
link: https://www.seci.co.in/tender-details/YmVz

Source 2: Original SECI RfS document
link: https://www.seci.co.in/uploads/tenders/RfS-ESS-Short_Term_Arbitrage.pdf