As India’s renewable capacity expands and grid flexibility becomes critical, merchant Battery Energy Storage Systems are stepping into a pivotal role – operating not as contracted assets but as market-responsive infrastructure. This whitepaper explores how merchant BESS monetizes price volatility, ancillary demand, and capacity shortages through diversified revenue participation. Supported by financial benchmarks, regulatory signals, and deployment case modeling, it outlines how investors and developers can structure, finance, and scale merchant storage portfolios while managing risk exposure and return variability.