On September 18, 2019, Chiba University and Keiyo Bank Ltd held an event at the "Chiba City Ookido Agri Energy Unit 1" (Fig. 1), a solar sharing-type solar power plant in Ookido Town, Midori-ku, Chiba City, Chiba Prefecture, Japan. The facilities and status of power generation and farming were disclosed at the event. Chiba University and Keiyo Bank have been promoting activation of the local economy based on a comprehensive collaboration agreement, and the event was part of their efforts.
The power generation and farming at the power plant are handled by Chiba Ecological Energy Inc of Chiba City, which is a venture company of Chiba University and is a solar sharing pioneer.
The event was held Sept 18, 2019, nine days after Typhoon 15, which made landfall and caused serious damage to Chiba Prefecture. Many greenhouses in the surrounding areas were damaged by the typhoon.
Under such situation, the typhoon caused no damage to the equipment at the Chiba City Ookido Agri Energy Unit 1. Facilities at solar sharing-type plants have a height of about 3m and are higher than general on-ground solar power generation facilities because agricultural machinery is used under the panels. And the distance between support pillars is also large. More careful consideration is also required for the toughness and reliability of the facilities at solar sharing plants, including load resistance in the event of continuous strong winds, compared with general on-ground facilities.
Screw piles were used in the foundations, and aluminum materials were used to build the support pillars (Fig. 2). Pile foundations are effective for cost reduction, but the safety is sometimes questioned. However, sufficient strength is ensured by screw piles if they are used appropriately, judging from the fact that the facilities at this power plant were not damaged at all during the typhoon while the strong winds caused serious damage to surrounding areas.