Abstract

High-temperature thermal energy storage is increasingly considered for decarbonising industrial process heat, particularly in applications requiring temperatures above 500 degrees C. Industrial heat demand and associated CO(2 )emissions are concentrated in a limited number of energy-intensive sectors including iron and steel, cement and other non-metallic minerals, chemicals and petrochemicals, aluminium and glass, where heat supply remains predominantly fossil-fuel based. HTES can support industrial electrification by decoupling variable renewable electricity supply from continuous high-temperature heat demand. This review evaluates sensible, latent, and thermochemical HTES technologies suitable for >500 degrees C industrial applications, focusing on operating temperature ranges, material performance, technology readiness and integration feasibility. The syntesis shows that sensible heat storage based on solid media and molten salts is currently the most technologically mature and widely deployed HTES option, reaching high technology-readiness levels and high efficiencies in power-to-heat systems supplying steam or hot air. Latent and thermochemical HTES offer higher storage densities but remain constrained by material degradation, limited cycling stability, internal heat-transfer limitations, slow or incompletely reversible reaction kinetics, and unresolved system integration. Process-level integration is found to depend on the specific sector, the heat-transfer interface, the continuity of operation and the delivered temperature, rather than on storage performance alone. The review concludes that near-term industrial deployment will be dominated by robust sensible systems, and that wider adoption requires long-term industrial demonstrations, standardised performance reporting, and levelised-cost-of-heat-based techno-economic assessment.