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Solar Plant Gets Int'l Certification for 1st Time in Japan (page 3)

Third-party German verification/test firm inspects system

2014/05/07 21:15
Kenji Kaneko, Nikkei BP CleanTech Institute
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Concern about solar panel wiring pointed out

To issue a certification, TUV SUD first examines the documentation, evaluates whether the system design is appropriate or not, and verifies if the construction is carried out in accordance with the design through visual and electric tests by actually visiting the power generation facility's site. After that, TUV SUD issues a certification if there are no problems.

In the case of "Yamaguchi City Aio MS Power Plant," West Holdings had prepared the required documents in November to December 2013 before the examination started. The plant inspection took place for about three days in January 2014, and the third-party certification was issued on February 14. In this case, the verification started after the plant's completion; however, in some cases, the assessment is carried out in parallel from the design phase (Fig. 5).

Should anything not meet the criteria after the plant inspection, TUV SUD would point it out in three grades of "critical," "major" and "minor" in accordance with the degree of seriousness. Compared with "critical," which is a serious failure that directly affects the qualification for the certification, "major" requires improvement, whereas "minor" only demands careful observation. The power producer would have to consider correcting or improving its system in accordance with each grade. In the case of "Yamaguchi City Aio MS Power Plant," there were no "critical" issues, but there were more than ten "minor" and "major" issues.

Among the indicated issues was an item concerning crossover cables that connect panels (Fig. 6). The cables were pushed above the panel at some points, and TUV SUD pointed out that the cables could shade the panels and affect their output depending on the hours of the day. Upon hearing this, West Holdings corrected the position of the cables so they would not shade the panels.

TUV SUD also suggested the wiring diagram and the emergency contact information should always be kept in the connecting and collecting boxes. This is for the purpose of enabling quick response if, for example, the PV system malfunctions. Partly because the deployment of a chief electric engineer in every site is mandated for mega-solar power plants in Japan, such considerations for third parties were barely given in some aspects. West Holdings improved all these issues pointed out by TUV SUD.

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