India's First Grid-Scale BESS: A Real-World Test of Software-Defined Energy Management
This report examines the 10 MW / 10 MWh Battery Energy Storage System (BESS) installed at a 66/11-kV substation in Rohini, New Delhi — India's first grid-scale battery installation. Commissioned in April 2019 for Tata Power Delhi Distribution Limited, the system uses NMC lithium-ion batteries and serves three critical grid functions: Deviation Settlement Mechanism (DSM) balancing, frequency regulation, and reactive power support.
Despite a full battery replacement by 2022, the installation kept experiencing accelerated capacity fade under its existing controls. In the second quarter of 2024, Ingro Energy deployed advanced software-defined controls onto the ageing system — creating a rare natural experiment: can intelligent energy management reverse a degradation trend that a hardware replacement could not?
The "Double Whammy" of Battery Degradation
Utility-scale batteries suffer a self-reinforcing degradation spiral. As State of Health (SoH) declines, the system must cycle more frequently to deliver the same grid services — and that extra cycling accelerates capacity fade even further. Left unchecked, each percentage point of lost capacity compounds the next, driving the system toward end-of-life well ahead of schedule. Delhi's 40°C-plus summers and daily DSM cycling made the Rohini system especially vulnerable.
The Intervention: Three Software Innovations
Ingro Energy replaced conventional sequential control with a cloud-based, AI-driven platform built on three pillars:
- Asynchronous Energy Management System (EMS) — simultaneous evaluation of multiple grid signals, with AI arbitration that weighs real-time module-level state of charge, temperature, impedance, cycling history, and the degradation cost of each dispatch decision.
- Cloud-based intelligence — continuous processing of more than 1,700 battery modules and thousands of parameters per second across 124 independent power-conversion units, with machine-learning models that improve over time and remote updates that need no site visits.
- Predictive battery management — module-level SoH forecasting, real-time State of Performance assessment, and early anomaly detection for predictive maintenance.
Measured Results
Before the intervention, the Rohini system was degrading at roughly 5 percentage points of SoH per year — well above the industry-standard 2–4% range, and accelerating. Once Ingro's controls calibrated to the system, the measured degradation rate fell to under 3 percentage points per year. That is a ~41% reduction in degradation velocity relative to the projected baseline trajectory.
Translated into operational life, the improvement extends the battery's usable lifespan to an 80% SoH threshold by approximately 70% — from around four years of remaining life to nearly seven, on the same hardware.
The Financial Case for Early Deployment
Slower degradation directly defers the single largest lifecycle cost of a BESS: battery replacement. A counterfactual analysis in the full report models what would have happened had Ingro's EMS been deployed at commissioning in 2019 rather than mid-life — preserving several additional percentage points of capacity and roughly doubling the years to end-of-life. For a system of this scale, avoiding a mid-life replacement corresponds to an estimated ~31% reduction in lifecycle CAPEX.
The core finding is simple: degradation is software-controllable. Intelligent cycling, thermal management, and cell balancing outperformed a full hardware replacement — at a fraction of the cost. The full report details the empirical SoH dataset (July 2022–July 2025), the counterfactual model, and the technical methodology behind these results.