Grid-India Proposes Integrating Solar, BESS and Pumped Storage into AGC and SRAS Framework

Grid Controller of India Ltd. (Grid-India), through the National Load Despatch Centre (NLDC), has released a consultation paper seeking stakeholder feedback on the Automatic Generation Control (AGC) of Renewable Energy Generating Stations (REGS), Battery Energy Storage Systems (BESS), and Pumped Storage Plants (PSP) in india. The paper has been prepared in compliance with directions of the Central Electricity Regulatory Commission and is based on learnings from pilot projects.

The proposal aims to create clear technical and commercial frameworks to allow these emerging resources to support grid frequency regulation. The paper notes that AGC operation of solar power plants is technically feasible, as demonstrated through a 180 MW pilot project at Devikot.

Solar plants are considered most suitable for SRAS-Down, enabling generation reduction during high-frequency events. While accurate MPPT signals are preferred, Grid-India said acceptable estimations can also work. For compensation, three models have been proposed,ranging from zero marginal cost settlement to partial tariff-based compensation with refunds to the pool, with or without performance incentives. Grid-India has recommended extending AGC and SRAS readiness to all solar plants of 100 MW and above.

BESS has been identified as one of the most effective resources for AGC due to fast response, high ramp rates, and bidirectional operation, backed by a 20 MW/40 MWh pilot. The paper proposes standardized protocols for State of Charge (SOC) and cycle management, while ruling out any mandatory cooling-off period between charge and discharge. Two compensation models are under consideration, a declared charge with mileage-based incentives, including a premium for superior performance, or a fixed weekly reserve charge. Grid-India also highlighted value stacking, allowing BESS to earn revenue through both SRAS and energy market participation.

PSPs have been found technically compatible with AGC in both generation and pumping modes, though certain operational constraints remain. To encourage participation, the paper proposes zero marginal cost settlement, exclusion of AGC-related energy from availability calculations, and eligibility for existing SRAS performance incentives. It also suggests extending the Beta factor incentive for primary frequency response in pumping mode and permitting AGC operation in technically safe overload zones.

For conventional hydro stations, Grid-India acknowledged that AGC-based down-regulation is commercially unattractive due to the notional nature of energy charge rates. To address this, the paper suggests extending zero marginal cost treatment for hydro down-regulation under AGC to unlock flexibility without financial penalties.

The consultation paper also encourages greater participation of intra-state generators, noting that around 6,800 MW is already active in regional SRAS. State Load Despatch Centres (SLDCs) have been urged to facilitate wider participation, paving the way for future state-level AGC operations once EMS upgrades are completed.

Grid-India has invited stakeholder comments on the proposed mechanisms by January 3, 2026, to be submitted via email.