Visit to Plant

Riverside Solar Plant Facilities Survive Flood of River

Remote monitoring of PV inverters added after automatic recovery failure

2019/10/29 14:56
Shinichi Kato, Nikkei BP Intelligence Group, CleanTech Labo
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The "Daiko Mibu Solar Power Plant," a mega- (large-scale) solar power plant with a solar panel capacity of 2.43MW and a grid capacity of 1.99MW, is located beside the Omoigawa River in Mibumachi, Tochigi Prefecture, Japan (Fig. 1).

Fig. 1: Daiko Mibu Solar Power Plant (source: Nikkei BP)

This mega-solar plant is in what was previously a quarry. The power producer, KK Daiko (Sano City, Tochigi Prefecture), originally ran a quarry business. To efficiently use the former quarry site, the company, having sold the quarry business as it finished quarrying the site, developed and now runs this mega-solar power plant.

NEC Networks & System Integration Corp (NESIC) proposed this mega-solar development to Daiko and commercialized it (See related article).

In early October 2019, the solar panels at the Daiko Mibu Solar Power Plant were inspected using a drone (unmanned flying vehicle) (Fig. 2). The drone was flown above the power plant and shot the panels from above using an infrared camera. Using the thermographic images obtained in this way, any panels likely to be malfunctioning were discovered.

Fig. 2: Panel inspection using drone (source: Nikkei BP)

As a result of this drone inspection at the Daiko Mibu Solar Power Plant, only three panels were found to have possible malfunctions (Fig. 3).

Fig. 3: Malfunction in cells (top), bird droppings (bottom) (source: NESIC)

In two of the above three photos, bird droppings covered some power generation elements (cells) and curtailed power generation. If the bird droppings were washed off, power generation would return to normal. In the other photo, however, the solar panel itself had a problem stemming from its cells.

Despite monthly fluctuations, the power generation amount has been almost flat throughout the year. In every year, the result reportedly outperformed the power generation estimate in the initial business plan by about 20%.

Solar panels of Toshiba Corp and PV inverters of Toshiba Mitsubishi-Electric Industrial Systems Corp (TMEIC) were adopted.