Visit to Plant

Bayside Solar Plant Focuses on Protection From Salt Damage

Minimizes risk of 20-year exposure to sea breeze through O&M

2014/07/20 02:00
Kiyotaka Nakanishi, Nikkei BP CleanTech Institute
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Fuji Sash Co Ltd's Chiba Plant is located along the seafront facing Tokyo Bay in Ichihara City, Chiba Prefecture, Japan. In the huge site, which is equivalent to eight Tokyo Domes, Fuji Sash manufactures sashes and other construction materials from dissolving aluminum metal to end products.

In March 2014, a total of 4,208 solar panels started generating power on the roofs of two logistics warehouses in the corner of this plant site (Fig. 1 & 2). It is a mega- (large-scale) solar power plant with an output of 1,376kW that can generate electric power equivalent to the consumption of 360 average families. This is the largest on-roof-type solar power system in Ichihara City.

The Chiba Plant is located within 500m of the coast in a so-called "heavy salt damage area." Salt damage can be found inside the plant site, with more rust generated as the plant buildings get closer to the sea. Based on these circumstances, Fuji Sash adopted a solar panel that complies with the highest "protection level 6" of the international standard "IEC61701" for salt water spray tests targeting panels.

Salt damage effect not properly foreseen

When it comes to heavy salt damage areas, it is generally recommended to install panels that feature "level 3" or higher protection.

"Given that there are few past results from operating a solar power generation system for 20 years, it is difficult to forecast the salt damage effect," Fuji Sash Production Manager Toshiaki Toyama said. "Accordingly, we thought it would be better to use a product that had passed the hardest test."

The logistics warehouses where the solar panels would be installed were situated in the area in the plant site farthest from the sea, but the panels on the roof would be exposed to the sea breeze. Being aware that the protection level 6 products would cost more, Fuji Sash gave priority to the panel's property that prevents lower output and other defects caused by salt damage.

Moreover, the company used installation clasps made of highly corrosion-proof aluminum-coated stainless steel (Nisshin Steel Co Ltd's "Alstar Stainless"), instead of conventional iron, to fix the panels to the logistics warehouses' folded-plate roof. Because Route 16 runs beside the logistics warehouses, Fuji Sash has to place priority on stopping the installation clasps from corroding, separating and falling from the roof.

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