Latent Heat Thermal Energy Storage (LHTES) using Phase Change Materials (PCMs) is a critical technology for balancing intermittent thermal supply with daily energy demand. However, the thermal performance of LHTES systems is fundamentally limited by the severe conduction resistance of organic PCMs, such as RT57HC, which exhibits a thermal conductivity of approximately 0.2 W/(m·K). To overcome this bottleneck, geometric and material enhancements—specifically longitudinal fins and metal foam matrices—are employed. While these structures increase conductive power, they displace bulk PCM capacity and act as momentum sinks that dampen beneficial buoyancy-driven natural convection during the melting phase. This project aims to numerically evaluate the power-to-capacity trade-offs of four configurations: a base vertical shell-and-tube LHTES, fin-enhanced tubes, foam-enhanced tubes, and a benchmark packed-bed architecture. The ultimate objective is to establish a rigorous multi-scale sizing methodology that scales these systems to meet the 80th percentile of a target daily energy demand curve. By bridging numerical thermal outputs (power and capacity) with a techno-economic framework, the study will determine the optimal system design based on total Capital Expenditure (CAPEX).