Long-Duration Energy Storage

Long-duration energy storage (LDES) is increasingly recognized as a vital component of a secure, low-carbon energy system. As fossil-based generation gives way to intermittent renewable power, LDES provides the flexibility needed to balance supply and demand over extended periods, maintain grid stability, and enable deeper renewable integration. Unlike short-duration systems, which typically address hourly fluctuations, LDES can support multiday or seasonal needs, reduce reliance on fossil peaker plants, and deliver resilience for critical facilities during prolonged outages. These capabilities position LDES as a foundational technology for achieving decarbonization and energy security goals.

This report analyzes the global market for LDES systems over the next decade with a particular focus on emerging technologies and their readiness for commercialization. Because most non-pumped hydro options are still early in deployment and face distinct challenges around cost, scalability, and market design, the analysis emphasizes technology readiness level (TRL) and the role of policy support in shaping near-term adoption. Capacity and revenue forecasts are based on project-level data from Guidehouse Research's Energy Storage Systems Tracker. Global cumulative LDES capacity (excluding pumped hydro) is expected to reach 439.4 GWh by 2034.

Despite growing interest, commercial viability remains constrained by high upfront costs, uncertain revenue streams, and inadequate market structures that fail to value long-duration flexibility. Regulatory complexity, permitting delays, and grid connection challenges add further risk, while the absence of standardized performance metrics complicates project evaluation. Many technologies are still scaling from pilot to commercial deployment, making it difficult to establish bankable business models. Market design remains the most critical barrier: without clear economic signals and long-term incentives, investment will be limited despite technical need. Sustained policy support will therefore be essential to enable market growth over the next decade.