Visit to Plant

5MW Solar Plant Built on 26-degree Sloping Dam Wall (page 2)

Slope specialists hired for construction

2016/06/21 15:21
Shinichi Kato, Nikkei BP CleanTech Institute
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A joint venture (JV) formed by Sanwa Electrical Engineering Co Ltd (Osaka City) and Novac Co Ltd (Himeji City, Hyogo Prefecture) was entrusted with the development of this mega-solar power plant at Kotani Dam. As a result, the same methods and products as those used at Heiso Dam were adopted for the power generation system, foundations and mounting systems.

The same JV also provided engineering, procurement and construction (EPC) services. Sharp Corp's single crystal silicon-type solar panels and Toshiba Mitsubishi-Electric Industrial Systems Corp's (TMEIC) PV inverters were adopted.

The JV deployed a method of forming mortar foundations on the rocks that cover the dam body surface (Fig. 4). The rocks on the surface of Kotani Dam are large, weighing from 1 to 2t and measuring from 1 to 2m each. The JV sprayed mortar in the metal net molds placed on the rocks.

Fig. 4: Foundations were formed on the rocks that cover the dam body. Spraying mortar (top) and completed foundations (bottom) (source: top Novac, bottom Nikkei BP)

The JV also adopted aluminum mounting systems and buried them in the foundations for holding. A hole to put a supporting post of the mounting systems was made in the center when forming each mortar foundation. The supporting posts were secured by pouring a mixture of cement and water in the holes where they were inserted.