Open-Source Models for Sand-Based Thermal Energy Storage in Heating Applications


  • Kathryn Hinkelman
  • David Milner
  • Wangda Zuo



District Energy, Load Shift, Modelica, Power-to-X, Renewable Energy, Silica Sand, Thermal Storage


This paper presents a new open-source modeling package in the Modelica language for particle-based silica-sand thermal energy storage (TES) in heating applications, available at Silica sand is an abundant, low-cost, and efficient storage medium for concentrated solar power and electricity generation. Although uncommon today, solid particle TES could benefit building and district heating systems, particularly as building electrification and renewable energy penetration increases. To enable heating system design and evaluation with sand TES, this work developed and open-source released Modelica models from base classes through complete systems with both physical equipment and controls. This paper first presents the new models. Then, we demonstrate their application with a heating plant that supplies steam for district heating, while also providing power-to-heat grid services by storing excesses renewable electricity as thermal energy.