Small modular reactors in future energy systems: A study of grid support, distributed energy systems, non-electric applications, and economic drivers

Small Modular Reactors (SMRs) are emerging as a potential low-carbon technology for grid decarbonization and industrial applications. This paper provides a comprehensive review and critical synthesis of SMR technology and its role in enabling operational flexibility and reliability in future energy systems. We systematically review 70 SMR designs, categorizing them by reactor type, technology readiness level, and operational characteristics. The literature is synthesized on four key aspects: (1) the technological capabilities of SMRs for grid support services, including inertia, frequency control, and load-following; (2) the potential for SMRs to enable non-electric applications such as hydrogen production, seawater desalination, district heating, and industrial process heat; (3) the role of SMRs in distributed energy systems, including microgrids, data centers, military installations, remote mining, and off-grid communities; and (4) the economic drivers and value of SMR integration with energy storage. The review identifies three main findings. First, SMRs demonstrate technical capability to provide essential grid stability services critical for enabling high-penetration variable renewable energy systems. Second, advanced SMR designs, particularly Generation IV reactors, offer high-temperature heat suitable for decarbonizing hard-to-abate industrial sectors, while micro-reactors provide viable solutions for remote and distributed applications. Third, economic analysis indicates that while SMRs show promise, their competitiveness depends on achieving sufficient deployment scale, learning rates of 10–20%, and supportive market frameworks for value-stacking. Significant challenges remain in licensing harmonization, fuel cycle infrastructure development (particularly for high-assay low-enriched uranium), material for high temperature operation, hybrid system control optimization, and public acceptance.