Recently, the Innovation Team of Plant Environmental Engineering of Protected Agriculture at the Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, together with the Institute of Refrigeration and Thermal Engineering, School of Mechanical Engineering, Tongji University, proposed a plant spectral complementation approach based on spectral-splitting solar light transmission and synergetic photovoltaic (PV) and thermal conversion. They also established a theoretical model of multi-wavelength light-matter interaction, which has important implications for reducing energy consumption in plant factories. The related research findings have been published in Energy.

Rationale and structure of the spectral splitting unit

Applying the solar transmission illumination technology to plant factories can significantly reduce the energy consumption of lighting systems in these facilities. However, only a portion of the visible light in the sunlight can directly participate in plant photosynthesis; the remaining could raise the ambient temperature within plant factories, thereby increasing the energy consumption of air conditioning. To enhance solar energy utilization and mitigate adverse infrared effects on optical fibers and plant factories, this study designed a solar transmission illumination system based on composite phase change material and PV and cooling integration.

The results show that PV cells operate steadily at 43.5°C, and the system achieves average power generation and light transmission efficiencies of 9.5% and 18.9%, respectively. The levelized cost of energy (LCOE) is 0.39 yuan/kWh, significantly lower than China's residential electricity price. LCOE is a quantitative indicator measuring the cost-effectiveness of energy projects throughout their lifecycles. This study offers a new path for realizing low energy consumption and sustainable development of plant factories.

This research was supported by the Beijing Municipal Science and Technology Project, Central Public-interest Scientific Institution Basal Research Fund, etc.

Linkage: https://www.sciencedirect.com/science/article/pii/S0360544225039465