Control Optimization of a Latent Thermal Energy Storage - Heat Pump System for Space Heating in Nordic Climate
Abstract
This study develops a hierarchical control framework for integrating phase change material thermal energy storage (PCM-TES) with heat pump systems for residential space heating in Nordic climates. The control architecture aims to optimise charging and discharging sequences of the PCM-TES to balance thermal comfort, operational costs, and grid flexibility services. A 42 kWh PCM-TES unit coupled with an 18 kW ground source heat pump is installed at the KTH Live-in-Lab (LIL) testbed, with control algorithms processing real-time temperature measurements, heating demand signals, and electricity price data. The framework employs a supervisory high-level control layer for operational mode selection and a component low-level control layer for actuator management. Charging sequences strategically store thermal energy during low electricity price periods, while discharging sequences ensure reliable heat delivery during peak demand or high electricity price periods. The control framework provides practical strategies for flexible sector coupling in residential buildings, supporting renewable energy integration and Nordic decarbonization goals.
Keywords
thermal energy storage (TES), phase change material (PCM), heat pump (HP), control strategy, renewable energy integration, flexible sector coupling (FSC)