聚光光伏光热系统

Abstract As the core of theoretical modeling for concentrated photovoltaic and thermal (CPV/T) systems, carrier balance (CB) and lattice thermal equilibrium (TE) in semiconductors are typically coupled solely at the maximum power point (MPP) of CPVs. Here, we demonstrate that this single-point coupling approach, derived from the Shockley model, introduces significant inaccuracies as it fails to capture the temperature-voltage (TV) characteristics of CPV/T systems. To address this limitation, a full-voltage-range coupling model (FRCM) is developed. This model reveals pronounced TV characteristics in CPV/T systems, resulting from voltage-dependent variations of CB-TE coupling induced by concentrated radiation, which are validated by experimental data. The TV characteristic markedly influences the current–voltage characteristic and total exergy efficiency ( η total ) of CPV/T systems through CB-TE coupling and results in a maximum exergy point distinct from the MPP. Using the FRCM, universal principles for enhancing η total through heat transfer adjustments are identified. Based on these principles, the theoretical limit for η total of an ideal CPV/T system is established. Wide-range calculations indicate that the theoretical η total can exceed 56 %. This work deepens the fundamental understanding of CPV/T systems and provides a robust framework for guiding optimization, contributing to unlocking their potential as highly efficient and sustainable energy solutions.