摘要： Global population growth and the ongoing climate crisis pose immense risk to the stable food supplies in the future. We have developed a small hydroponic plant cultivation system to ensure even in extreme circumstances. To build a sustainable system, we have utilized an LED lighting system together with conserved energy generated by sunlight. Such hydroponic plant cultivation systems have to operate at an affordable yet efficient principle. In this paper, we examine experimental results of the relationship between LED energy consumption and plant growth in a hydroponic plant cultivation system. LED light intensity directly correlates to electrical power consumed. Energy consumption is the result of electrical power consumed over a period of time. Three experiments with varying conditions utilizing constant electrical energy consumption were conducted. Case-1: Electric power is kept low and the lighting duration is long; Case-2: the electric power is set to medium and the lighting duration is medium; Case-3: the electric power is large and the lighting duration is short. As a result of evaluating the weight of grown lettuces, it was found that lettuce growth is excellent in Case-1. It means that the longer the LED irradiation duration, the better the plant growth even under the same energy consumption conditions.