Numerical analysis and performance investigation of holographic spectrum-splitting concentrated photovoltaic-thermoelectric hybrid system with phase change material

Abstract

To address the fluctuating nature of solar energy and achieve full spectrum utilization, a novel holographic spectrum-splitting concentration photovoltaic-thermoelectric hybrid system with phase change material is proposed in this study. Specifically, a two-layer volume holographic grating splitter is designed to separate the targeted spectrum from incident solar radiation for three spatially separated photovoltaic cells, while the thermoelectric module is employed to recover the residual heat from photovoltaic cells for electricity generation subsequently. Then, a heat storage layer with paraffin is positioned between the photovoltaic cells and the thermoelectric module to stabilize the temperature fluctuation and prolong the operation time for thermoelectric module. Thus, the conversion efficiency of solar to power can be significantly enhanced and a stable power supply is achieved by the proposed system. A thermodynamic mathematic model is established in this study, and the energy, exergy, and economic analysis are conducted comprehensively. The results show that under optimum conditions, the total energy and exergy efficiency of the proposed system reaches 30.2 % and 32.4 %, respectively. Among all components, the heat sink for thermoelectric module is the most inefficient component and highest exergy destruction is observed in the photovoltaic cells.