The utilization of phase change materials (PCMs) with concentrator photovoltaic (CPV) systems for energy storage and thermal management is limited. This is mainly due to the low thermal conductivity and poor heat transfer from the CPV cell to the PCM. In the current study, a novel design of encapsulated phase change materials integrated with a concentrator photovoltaic system is developed to enhance the conversion and thermal efficiencies of CPV systems. The new design enhances the effective thermal conductivity of the PCM-based heat sink and allows for rapid heat dissipation from the CPV cell. Two different sets of PCM enclosures are considered and compared to a conventional heat sink without encapsulation. The first set includes single, double, and triple encapsulated PCMs. The second set consists of four enclosures, each with three capsules having a combination of PCM arrangements with different melting temperatures. To assess system performance, a two-dimensional model of photovoltaic layers integrated with encapsulated phase change material-based heat sink is developed. The model is numerically simulated and validated with experimental and numerical data. Results indicate that triple encapsulation reduces the average cell temperature by 16 ℃ and non-uniformity index by 24 ℃, compared to the conventional heat sink. In addition, using triple-encapsulation results in higher electrical output power, thermal energy storage, and lower heat loss. Moreover, the system's cumulative electrical and thermal efficiency is enhanced by 21.3 % and 5.29 %, respectively. The findings introduce a more efficient design that can accommodate a worldwide increase in energy demand.