Solar Greenhouse Illumination Using Smart Artificial Lighting System

Agrivoltaics gives a promising solution in providing dual production of food and electricity. However, as a closed agrivoltaic system, the solar greenhouse experiences a problem of optimizing the natural light in generating electricity and producing crops at the same time. The roofing solar modules prevent the plants from receiving adequate amount of sunlight that they need for photosynthesis in exchange for higher power generation. Thus, this research project explored the implementation of a smart artificial lighting system tailored to supplement light for the plants. An adaptive control algorithm based on the correlation of outdoor solar irradiance and the ambient light inside the solar greenhouse was developed to dynamically adjust the illuminance of artificial lights. The Internet of Things (IoT) technology was integrated into the system to remotely monitor the variations in ambient light, solar irradiance, and energy consumption of the artificial lighting system. The effect of the dimmable lighting system on plants and energy consumption was compared to that of the control setup having no artificial lights and the setup with non-dimmable lights. Results showed that the lighting system improved the growth and quality of plants relative to that of the control setup. It consumed less energy than that of the non-dimmable artificial lights. It can be supplied by the harvested energy from the roofing solar module. Furthermore, its benefit-to-cost ratio from its one-month operation was found to be economically desirable, but it needed improvements to become a better system than the control setup.