A Solar-Driven hybrid dehumidification system with spectrum splitting technology for efficient operation across a broad range of humidity

Solar-driven dehumidification systems, as a clean and sustainable technology, have attracted much attention. To expand its applications, it is necessary to improve its dehumidification efficiency and range. This study develops a solar-driven hybrid dehumidification system integrated with spectrum splitting technology. Spectrum splitting technology can separate long- and short-wavelength solar radiation, making them convert into electricity and thermal energy concurrently in a decoupled way. Subsequently, a new dehumidification configuration is proposed to efficiently leverage the converted energy, where vacuum membrane dehumidification systems (relying on electricity) and liquid desiccant dehumidification systems (relying on thermal energy) are combined in series to dehumidify the air. Such dehumidification configuration under various operation conditions is theoretically assessed. The results show that solar energy converted electricity is not fully utilized, and the air humidity ratio remains high. An improved configuration is subsequently developed, including additional vacuum membrane modules in the vacuum membrane dehumidification system to further reduce the air humidity ratio and a battery to store the excess electrical energy while handling the intermittency of solar energy. The performance of the improved configuration is theoretically assessed regarding the lowest air humidity ratio, exergy efficiency, and operation duration. The results show that the air humidity ratio can reach below 1 g/kg, meeting most application scenarios. The exergy efficiency can reach up to 6.2 %, representing an increase of up to 100 % compared to previous systems. Moreover, the proposed configuration can operate all day at various humidity levels by optimizing the concentration ratio. The proposed configuration provides a promising way for clean and efficient dehumidification across a broad range of humidity levels. © 2025 Elsevier Ltd