A numerical framework for an electrically-charged PCM brick to reduce winter peak heating demand

Abstract

Abstract The substantial peak electrical demand for space heating in cold and freezing climates poses a significant challenge to grid stability and energy affordability. This study proposes and numerically investigates a novel active thermal energy storage system integrated directly into a building brick to address this challenge. The system features an encapsulated Phase Change Material (PCM) composite, enhanced with a high-conductivity copper oxide foam, and is coupled with a low-wattage electrical heating element. This design enables the brick to function as a ‘thermal battery,’ charging with off-peak electricity and discharging heat during peak demand periods. A comprehensive computational fluid dynamics (CFD) model was developed to analyze the system’s performance under severe winter conditions, with ambient temperatures as low as − 30 °C and varying electrical power inputs. The results demonstrate a profound improvement in the indoor thermal environment. While an unheated brick’s surface dropped to − 5 °C, the active system maintained it above a stable + 8 °C, delivering a peak heat output of over 150 W/m² to the living space. This effective load shifting reduced the wall’s net daily energy loss by nearly 70%, significantly lessening the burden on the primary HVAC system during peak hours. The findings confirm that the proposed active PCM-brick is a highly effective and viable solution for peak-shaving, enhancing occupant comfort, and improving the energy resilience of buildings in cold climates.