Electrically driven composite phase change materials for latent thermal energy storage in localized space heating: Progress, challenges, and prospects

Electrically charged phase change materials (PCMs) provide high energy-density, solutions for localized space heating, and reducing peak electricity demand, and provide alternative against power disruptions. This review consolidates a distinct contribution compared with previous PCM–TES studies by consolidating recent advancements, identifying challenges, and outlining strategies specifically for electrically powered latent TES. Key challenges exist at both material and system levels, the challenges related to materials include trade-offs in composite composition required to overcome inherent thermophysical limitations, which directly affect performance long-term reliability. Selecting melting points that align with seasonal and daily heating demand as well as electrical duty cycles remains challenging, further restricting adoption, consideration of material source origin to assess economic and environmental viability through a 4E perspective. System-level barriers include inefficient encapsulation strategies, trade-offs between compactness and heat transfer, and the lack of adaptive control systems integrating occupancy patterns, ambient conditions, and variable electricity pricing. Quantitative trends from recent studies show that electrically driven PCM and composite PCM (CPCM) heaters can reduce peak electricity demand below 10%, achieve 1.7 times higher thermal storage than conventional TES based on sensible heating, and lower operating costs by approximately 15%. Cascaded latent heat storage using multiple PCMs with staggered melting points delivers 5–14% higher storage capacity and up to 15% exergy gains over single-PCM systems. Optimized heat exchanger and container geometries further reduce melting time by up to 28%, improve cycle-level energy savings by over 2.5 kWh, and enable cumulative savings of hundreds of kWh over repeated charge–discharge cycles.