2015 年 81 巻 821 号 p. 14-00294
In this study, compactification (improvement of the light receiving density) and reduction of the directivity (dependence property for the sun position) are tried to improve the efficiency of the photovoltaics using Light Received Analysis Algorithm of a Plant Shoot (LAPS). The LAPS is a method of analysis to check the form of a plant shoot that has high light receiving density by numerical analysis using GA. A big scale plant needs big energy for maintenance and growth. A characteristic of the big scale plant is to have a branch structure. Thus, it means that a branch structure is necessary to get big energy by the solar cell module simulating a plant shoot. However, conventional LAPS was not able to express the branch structure so far. Therefore L-system is applied to LAPS. The purpose of this paper is to elucidate the influence that the branch structure gives to light receiving density. The analysis is carried out under sunshine condition of the summer solstice and the winter solstice in Sapporo, Hokkaido, and used a ginkgo for the shape of the leaf. As results, solar cell modules with the branch structure of a plant shoot optimized for sunshine condition of the summer solstice and the winter solstice were obtained. As the number of leaves increased, the solar cell module with the branch structure of a plant shoot came to have higher light receiving density than that of the solar cell module without the branch structure of a plant shoot. From this, it is confirmed that the branch structure increases the light receiving density of a plant with many leaves.