A comprehensive review of battery and hydrogen storage systems across technical, economic, and environmental dimensions

The decarbonization of power systems through high-penetration variable renewable energy (VRE) integration critically depends on grid-scale energy storage to mitigate intermittency and enhance reliability. This review provides a systematic, quantitative comparative analysis of two leading storage technologies Battery Energy Storage Systems (BESS) and Hydrogen Storage Systems (HSS) based on water electrolysis with subsequent fuel-cell reconversion across technical performance, economic viability via Levelized Cost of Storage (LCOS), and environmental impacts via lifecycle assessment (LCA). The methodology entails a systematic literature review of peer-reviewed studies and authoritative benchmarks from recent years. To ensure comparability amid heterogeneous studies that differ in boundary conditions, cost reference years, discharge durations, operating assumptions, and geographic contexts, monetary values were harmonized using inflation adjustment where applicable; LCOS was prioritized or contextualized as the primary unifying economic metric, incorporating sensitivity to key parameters such as discharge duration and cycle life; and LCA results were interpreted with attention to consistent functional units (primarily per kWh of delivered energy) while highlighting sensitivity analyses (e.g., recycling rates and grid carbon intensity). The analysis is limited in scope to grid-scale applications supporting VRE integration, with primary emphasis on representative lithium-ion BESS chemistries and green HSS pathways. Key findings establish a complementary, non-competitive relationship: BESS excels in high round-trip efficiency (85–95%), millisecond-scale response times, high cycle life, and competitive short-to-medium duration storage, rendering it suitable for frequency regulation, arbitrage, and daily cycling. In contrast, HSS provides superior gravimetric energy density (120–142 MJ/kg), near-zero self-discharge over extended timescales, and advantages for long-duration and seasonal storage, despite lower overall chain efficiency (typically 35–50%). Environmental considerations reveal trade-offs, with BESS facing notable upfront impacts from critical material extraction (e.g., lithium, cobalt, nickel) that can be partially mitigated through improved recycling, while green HSS offers lower operational emissions but involves infrastructure-related burdens. The novelty of this work resides in its multi-dimensional, side-by-side quantitative framework that integrates recent benchmarks, standardized LCOS and LCA metrics with explicit harmonization of assumptions for improved comparability, and an explicit complementarity perspective grounded in imperfect substitution dynamics moving beyond the qualitative overviews or application-specific comparisons common in prior reviews.