North-facing Solar Plant Produces Enough Power
Concrete under arrays prevents erosion by muddy water
Yae District of Irikicho, Satsumasendai City is about a one-hour drive from Kagoshima Airport, in the mountains to the west of Kagoshima Prefecture. Before the war, it was a small mountain village, but multiple new settlements were built as settlers increased after the war.
Land cleared by settlers
The Yaeshikano area is one such settlement. As you drive up a narrow road that is just wide enough for a car, the forest suddenly ends just before the "Kaitaku Kinen no Mori Noen" monument. Beyond this monument, on the way to the summit, the "Satsumasendai Former Frontier Solar Power Plant" with an output of 1.8MW is located on a slope. Construction started in May 2016, and operation started in January 2017 (Fig. 1).
The 3.5ha mega- (large-scale) solar power plant site is narrow and long while the difference in height is roughly 50m. The steep slope had previously been reclaimed as terraces and used for farming. But as it grew less and less used with each succeeding generation, it became wasteland covered with grass and bushes. It was owing to such circumstances that the landowner thought of utilizing the site for solar power generation.
That said, the sloping site was not only located in the steep mountains but also faced north. It was a typical "bad location" for solar power generation business. Solar power developers would usually never be interested in this location. However, Shizen Energy Inc (Chuo-ku, Fukuoka City), which had been consulted, purchased the land and embarked on development, believing it could secure a sustainable business there.
Although sloping, the area was reclaimed as terraces where panels with an output of nearly 2MW could apparently be set up, and a relatively large gentle slope could be secured in the middle of the site while the connecting high-voltage power distribution line reached the adjoining road. Including these factors, the site had some other beneficial aspects for business sustainability.
Shizen Energy, where many civil engineering experts work, had also previously constructed some mega-solar projects on such north-facing slopes.