CERC allows 50 MW-plus BESS projects non-solar hour transmission access

The Central Electricity Regulatory Commission (CERC) notified the Fourth Amendment to its connectivity regulations on 11 November. The update permits battery energy storage system (BESS) projects with a capacity of 50 MW or more to access transmission infrastructure during non-solar hours.

The commission did not specify a particular date for the amendment to take effect.

Connectivity and Storage Requirements

The Central Transmission Utility (CTUIL) will publish a monthly list identifying substations with available transmission margins. To qualify for non-solar hour access, storage systems must possess an energy capacity at least twice their power capacity. For instance, a 200 MW facility requires 400 MWh of storage. Crucially, the amendment does not provide fresh transmission augmentation for this access.

Financial and Operational Relief

• Bank guarantees for Conn-BG2 and Conn-BG3 are returned one week after one year of commercial operation.
• The previous schedule required the return of these guarantees in five equal instalments over five years.
• Existing projects that have completed one year of operation will receive their guarantees back within one month of the amendment.
• Developers may withdraw connectivity if the final grant is delayed by two years past the in-principle grant.
• Withdrawal is also permitted if the start date is delayed by two years.
• Partial withdrawal of the connectivity allocation is not permitted.
• The application fee is forfeited upon withdrawal.

Source Change and Deadline Flexibility

Developers facing expired application windows receive a one-time 30-day extension to regularize their status. This second change carries a fee of ₹20,000 per MW or ₹10 lakh, whichever is higher. If a developer simultaneously requests a change in land parcel, the fee rises to ₹25,000 per MW or ₹10 lakh, whichever is higher.

Developers may now submit source-change requests up to six months before their firm start date. This represents a significant shift from the previous requirement, which mandated applications 18 months prior to the start date.

Market Context and Targets

Ministry of Power data as of 30 June 2026 outlines the current scale of storage deployment and the government’s long-term integration goals.

Stage	Capacity (MW)	Energy (MWh)
Under construction	15,754	42,530
At tendering	19,192	67,574

These figures sit within a broader national strategy to integrate 47 GW of BESS capacity by 2031-32.

Sub-lease Documentation and Route Conversion

The amendment accepts sub-lease documents between parent and subsidiary companies, or between sibling subsidiaries, subject to specified conditions. Connectivity originally obtained through the land route can now be converted to the power purchase agreement route for part or the entire project capacity. Developers must submit withdrawal applications within 45 days of the relevant delay event, and those whose application windows have already expired receive a one-time additional period of 30 days.