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Riverside Solar Plant Facilities Survive Flood of River (page 3)

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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Such a design proved effective when Typhoon No. 18 struck in September 2015.

At that time, record-breaking heavy rain continued to fall across the northern Kanto region while a broken dike and flooding caused serious damage in the Kinugawa River basin in Joso City, Ibaraki Prefecture.

The Omoigawa River next to the Daiko Mibu Solar Power Plant runs almost in parallel about 10km to the west of the Kinugawa River. It is located upstream from where the Kinugawa River flooded. Despite different discharge rates and other river conditions, the situation regarding the heavy rain seemed to be similar for both rivers.

At that time, a lot of water increasingly pooled under the panels in addition to the two reservoirs at the Daiko Mibu Solar Power Plant. Although the foundations and mounting systems were submerged on the south side where the ground had been lowered and the water level increased further, the power generation facilities fixed on the mounting systems survived the typhoon without being submerged even at the south end. The power plant believes this proves its preliminary design had been sufficient.

That said, power selling stopped at the power plant. An instantaneous drop on the grid side caused the safety feature of the PV inverters to be activated and stop operation. Such an operational stop due to an instantaneous drop can usually be restored automatically. This time, however, the operation was not restored due to a problem.

The power plant noticed the failure of automatic operation recovery about four days later. It did not immediately notice it because a remote monitoring system was not adopted for the PV inverters. Following this failure, the plant added a remote monitoring system for the PV inverters.