Regional specialty 'Yellow Heart'
Pumpkins are grown on many of the sites because they grow well in weeds and require nearly no weeding, which is suitable for natural cultivation without using herbicides and reduces the burden on the farmers. A variety called "Yellow Heart," which is the specialty of the region, was selected (Fig. 6).
Japanese ginger and asparagus that grow well in shade were selected for the power plants attached to greenhouses because the shading rate increases when solar panels are installed effectively in the limited empty spaces.
The plants were designed and constructed by companies based outside the region that undertake construction of solar sharing power plants throughout Japan and local construction companies. As a result, various types of panels, PV inverters and mounting systems manufactured by multiple companies were employed.
Narrow reed-shaped solar panels were used in some of the plants, while general types with 60 cells per panel were used in others. Two types of mounting systems, those made by connecting single pipes with joints and special mounting systems made of aluminum, were used. A system for moving panels is used in one of the sites (Kubo Power Plant). Panel angles are changed depending on the season and in line with the culmination altitude of the sun (Fig. 7).