What became a challenge when setting up the mounting systems were the concrete foundations left from the former pigsties. Should they be removed in a large-scale project, initial investment would increase too much to maintain revenues from the solar power business. Based on these circumstances, the plant decided to leave the concrete foundations untouched and minimize the impact on driving the stakes by arranging the disposition of the mounting systems (Fig. 6).
Water control to prevent "nuisance facility"
Along with the selection of facility equipment, juwi Shizen Energy has focused on "power plants that harmonize with the local community" throughout its mega-solar power plant constructions overseas. The company provided presentation meetings jointly with the neighborhood association after signing a location agreement with Kumamoto Prefecture and Ozu Town.
"One of the factors that make mega-solar power plants 'nuisance facilities' overseas is the water issue," Manager Kasama said. "Given their poor water retaining ability, mega-solar power plants can easily attract complaints as soon as rainwater runs in a specific direction."
Ozu Solar Power Plant, which looked "like a jungle in the beginning," was constructed by cutting down the plants and trees growing there. This made the local residents concerned about the water discharge issue caused by weakened water retaining ability. And some raised water-related questions at the joint presentation meetings with the neighborhood association.
In Japan, there is no obligation to set up a water discharging facility at solar power plants because the installation of a solar power generation system does not correspond to a "development action." Accordingly, most mega-solar power plants in Japan only establish a simple ditch and consider further action in accordance with any water accumulation and other factors after the operation has started.
On the other hand, Ozu Solar Power Plant asked Japanese civil engineering experts who know about Japanese ground formations to calculate the area’s maximum amount of water retention and water penetration ratio, in addition to juwi's findings, and constructed water passages using a U-shaped gutter. The civil engineers also buried boards to block groundwater streams and dug holes to move the water running out from the solar power plant in various directions.
"For a mega-solar power plant run by low-profile venture companies and foreign enterprises to be accepted by the local community and then take root, it is necessary to pay more consideration to the local community compared with the domestic leading companies," said Manager Kasama, standing in front of the mega-solar power plant, which has started operating smoothly.