Visit to Plant

Chinese Power Company Runs Solar Plant in Harmony With Local Community (page 4)

Japan's largest solar sharing operation in Tsukuba City

2018/03/06 00:46
Kenji Kaneko, Nikkei BP Intelligence Group, CleanTech Institute
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Korean ginseng grown under the panels

Solar panels with an output of about 35MW were set up across approximately 54ha of farmland at the "SJ Solar Tsukuba Power Plant," which started operation in Mimori District, Tsukuba City, in April 2017. SJ leveraged a program to temporarily use farmland for solar power generation in the area where mounting systems were installed. This became Japan's largest solar sharing (farming solar power plant) project (Fig. 8).

Fig. 8: The SJ Solar Tsukuba Power Plant (source: SAAE)

Using conventional solar panels (60-cell, 265W/unit), arrays (a unit of panel installation) of five sideways panels of four rows each were tilted by 15°, with the lowest part of the panels set up 2m from the ground using pile foundations. Each array was supported by a total of four pile foundations, which were set up at the back and front, and the right and left. The back and front pile foundations were spaced about 3m from each other. These basic arrays were spaced 2.2m from each other (Fig. 9). As a result, the ratio of light shielding surpasses 50%.

Fig. 9: Farming continues under the panels set up 2m from the ground. (source: Nikkei BP)

As panels were set up 2m from the ground and pile foundations were spaced 3m from each other, tractors and other agricultural machines can be used for farming. Mimori-no Sato, a farming corporation formed primarily by local farmers, produces Korean ginseng, ashitaba and coriander, among others (Fig. 10).

Fig. 10: Korean ginseng is farmed. (source: Nikkei BP)

In solar sharing, narrow and long reed-shaped panels are used, and rice and soy beans are sometimes raised if the ratio of light shielding is limited to about 30%. If the ratio exceeds 50%, like at the site in Tsukuba City, however, "semi-shade farming products" that grow with about half the amount of sunshine are suitable. SJ said it had selected Korean ginseng from such a perspective.

SJ runs the power generation business by renting the land where pile foundations are set up from the farming corporation. The corporation can carry on with agricultural work while obtaining a stable income through rent.

Lawn grass had originally been farmed in this district, but the amount of abandoned farmland was increasing amid the weakening demand for such grass reflecting the decreasing number of golf courses in Japan. Based on these circumstances, the farming corporation decided to join hands with SJ by leveraging the program to temporarily convert the use of farmland in the course of exploring ways to rent farmland to mega-solar plants.

Many foreign solar power developers sell their power plants after their operation begins, but "SJ will not sell its power plants because it is an electric power company and makes investments in Japan to undertake the power generation business itself," Tsukamoto said.

"To continue power generation business for 20 years or more, it is indispensable to cooperate with local communities," he said. "We give priority to being accepted by local communities and continuing power generation business, rather than pursuing high returns."

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