Solar Plant Exploits City Policy on Landfill (page 3)
Integrated foundation resolves construction restrictions
Fig. 2: Nine mega-solar power plants and four wind power plants are integrated in Hibikinada area. Output ranges from 1MW to 20MW at the solar power plants and from 2MW to 15MW at the wind power plants. (source: Hibikinada Development).
Fig. 3: Flying near the windmill is an Eastern march harrier, which is designated an endangered species. A waste disposal facility turns into an untouched natural environment, where rare species live. (source: Nikkei BP)
Fig. 5: Concrete pieces that combine the foundations and the mounting system are put in place. As concrete foundations could not be built on the ground, the resistance required to set up solar panels was secured by the weight. (source: Nikkei BP)
Given these circumstances, concrete foundations cannot be built on the ground as they are in general large-scale solar power plants. Accordingly, the plant adopted a method in which a concrete piece that integrates the foundation part and the mounting system is placed on the ground.
Deployed was Kokura Cement's "Solar Keeper." Excluding the clasps to attach the solar panels, every other part is made of concrete (Fig. 5) so the required resistance can be secured by its own weight even without building up the foundations.
This system features more benefits than the weight that secures the resistance required for solar panel installation. First, the concrete model's durability is superior to that of general metal models. Given the location near the sea, its durability was also a key factor to be focused on not only against wind pressure but also against salt damage.
Weeds do not grow under the solar panels where the ground is covered by concrete (Fig. 6). This effect can also cut the cost for weeding.
While the PV inverters' total capacity is 1.990MW, 8,008 solar panels for an output of 2.002MW were installed. The installation angle of the panels is 20°. As the angle makes the shadow of the adjoining panels to the south shorter, the plant could array more solar panels than had first been expected.
Space for service vehicles to operate has been set out in a grid inside the mega-solar power plant. This space is needed not only for operation and maintenance of the power plant but also for soil purification. An adjustment ditch was also established for drainage (Fig. 7).
Along with the concrete foundations that cover the ground under the solar panels, weed control sheets are used between the rows of solar panels as another measure against weeds.