Energy consumption of plant factory with artificial light: Challenges and opportunities

Plant factory with artificial light is proved to be a promising technology for relieving the food crisis, especially in urban areas or arid regions endowed with abundant resources. However, lighting and heating, ventilation, and air conditioning systems of plant factory with artificial light have led to much greater energy consumption than open-field and greenhouse farming, limiting the development and global application to a wider extent. Researches in the last few years focus on the optimization of energy consumption to develop and promote the plant factory with artificial light technology with reduced energy usage. The review in this work seeks to overview energy consumption analysis as well as energy-saving technologies that can enhance the feasibility of the plant factory with artificial light. Specifically, the paper reviews various energy-saving designs and case studies, indicating that the lighting energy-saving design mainly focusing on the optimization of light intensity, light spectrum and light period can save up to 45 % energy consumption based on experiments, while heating, ventilation, and air conditioning systems optimization can save up to 50 % energy consumption mainly based on simulation. Future studies on efficient equipment, artificial intelligence technology, renewable energy integration and advanced energy material application are important for developing plant factory with artificial light. These promising improvements will provide more crop yield with lower energy consumption and carbon emissions to achieve resource sustainability and relieve the food crisis.