Simulation-guided design of solar steam generator arrays for efficient all-cold evaporation under natural sunlight

Solar-powered interfacial evaporation has emerged as a promising, sustainable technology for clean water production with its minimal carbon footprint. Currently, extensive research efforts focus on enhancing solar evaporation rates and broadening the applicability of three-dimensional (3D) interfacial steam generators (SGs). For large-scale water production, individual 3D SGs must be integrated into system-level SG arrays for deployment in portable devices or solar distillation plants. Therefore, the SG array’s configuration plays an even more critical role in boosting solar evaporation. From a methodological perspective, the development of numerical simulation and evaluation methods to predict the solar evaporation of SG arrays is an emerging research frontier. Nonetheless, the complex energy–water–solute interactions within SG arrays remain largely underexplored. Herein, 3D SGs and their integrated SG arrays are developed. The temperature, relative humidity, airflow, and air particle distributions throughout individual SGs and SG arrays are simulated, guiding the optimization of SG structures and the arrangement of SG arrays. By promoting cold evaporation, 8-Fin SG achieves the highest water evaporation rate of over 2.3 kg m–2 h–1 under 1 sun, with a further increase to 4.8 kg m–2 h–1 under a moderate airflow, positioning it among the best-performing solar-powered SGs. The circular array configuration of nine 8-Fin SGs (12 cm spacing) enables sustained “all-cold evaporation” in each unit, where continuous energy harvesting from both ambient air and bulk water drives an exceptional evaporation rate of 5.9 kg m–2 h–1 of the SG array under natural sunlight. We present an integrated approach combining numerical simulation with experimental studies of SG and their arrays, inspiring a new paradigm for advancing SG arrays toward system-level applications.