Numerical Investigation of a Multi-Year Sand-Based Thermal Energy Storage System for Building Space Heating Application
Journal: Buildings
Year: 2026

Residential space heating in Northern Europe requires long-duration thermal storage to align summer solar gains with winter heating demand. This study investigates a compact sand-based seasonal thermal energy storage integrated with flat-plate solar collectors for an A+ class single-family house in Kaunas, Lithuania. An iterative co-design couples collector sizing with the seasonal charging target and a 3D COMSOL Multiphysics model of a 300 m3 sand-filled, phenolic foam-insulated system, with a