Recently, the Team of Plant Environmental Engineering of Protected Agriculture at the Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, discovered that using wall-embedded composite phase-change materials enables photothermal decoupling of indoor sunlight, offering new insights for optimizing greenhouse light-thermal environment control strategies. The related research findings have been published in Energy.

The solar greenhouse, commonly known as a "warm shed", is a representative of low-carbon energy-efficient greenhouses in northern regions. Crops distributed in the northern section of the solar greenhouse often experience poor light conditions due to shading effects caused by the north-south plant spacing and the greenhouse structure itself. Moreover, during winter nights, the low temperature inside the greenhouse can also affect the quality and yield of vegetables and fruits.

This study designed a columnar phase-change energy storage device (CESD) installed on the north wall, using cesium tungsten bronze (CsxWO3) nanoparticle-composite CaCl₂·6H₂O as the spectral separation medium. After passing through the CESD, sunlight undergoes photothermal decoupling. Infrared radiation is stored by the composite phase-change material, while photosynthetically active solar radiation is reflected by the CESD to facilitate crop photosynthesis. The passive solar-thermal energy storage system in this study features structural simplicity, low cost and high thermal energy storage density. Through this system's regulation, the experimental greenhouse in Beijing achieved an average increase of 2°C in nighttime temperature and a 17.5% improvement in plant growth light levels.

This study was supported by the Special Fund for Central Government Guidance on Local Science and Technology Development and the Innovation Project of the Chinese Academy of Agricultural Sciences.

Linkage: https://www.sciencedirect.com/science/article/pii/S0360544225027719