In most concentrated photovoltaic–thermal systems, solar energy that cannot be used by photovoltaic cells is recycled for the thermal process. The unutilized energy is converted into thermal energy for driving other processes. This increases irreversible losses and restricts the efficient utilization of high energetic photons. To address these challenges, a concentrated photochemical–photovoltaic–thermochemical system is proposed to use the full spectrum of solar energy more efficiently. Photons with photonic energy significantly higher than Eg (the bandgap of photovoltaic cells) are used in the photochemical process, and the below-Eg loss of photovoltaic cells is recycled to provide heat for the thermochemical process. The proposed system realizes the cascade utilization of the full-spectrum solar radiation and can use high-energy photons more efficiently. The irreversible loss from the proposed system is decreased, resulting in higher solar utilization efficiency. The numerical results clearly show that the proposed system outperforms concentrated photovoltaic systems, concentrated thermochemical systems, and concentrated photovoltaic–thermochemical systems. The solar utilization efficiency of high-energy photons (before 600 nm) is increased from 44.01% (of common concentrated photovoltaic–thermal systems) to 80.68%. The total solar utilization efficiency in the proposed system attains 66.95% under the design condition.

在大多数集中式光伏热系统中，光伏电池无法使用的太阳能被循环用于热处理。未利用的能量被转换成热能以驱动其他过程。这增加了不可逆的损失，并限制了高能光子的有效利用。为了应对这些挑战，提出了一个集中的光化学-光伏-热化学系统，以更有效地利用整个太阳能。在光化学过程中使用光子能量远高于Eg（光伏电池的带隙）的光子，而低于Eg损失的光伏电池被回收以为热化学过程提供热量。该系统实现了全光谱太阳辐射的级联利用，可以更有效地利用高能光子。所提出系统的不可逆损失减少了，从而提高了太阳能利用效率。数值结果清楚地表明，提出的系统优于集中式光伏系统，集中式热化学系统和集中式光伏-热化学系统。高能光子（600 nm之前）的太阳能利用效率从44.01％（普通集中式光伏热系统）提高到80.68％。在设计条件下，拟建系统的总太阳能利用效率达到66.95％。