Solar Plants Damaged by Typhoons in Summer (2)

Multiple sites in Izu Peninsula damaged, some arrays turned over

2019/12/14 09:34
Kenji Kaneko & Shinichi Kato, Nikkei BP Intelligence Group, CleanTech Labo
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Continued from Solar Plants Damaged by Typhoons in Summer (1)

Mounting systems also damaged in Izu Highland

These accidents are only a small part of the damage caused to solar power plants by typhoons. Low-voltage solar power plants with a grid output of 10 to 50kW, which make up 80 to 90% of the solar power plants for business use in Japan, are not required to report accidents, and METI is unsure of the damage situation at such plants.

Another solar power plant in Izu Peninsula, which was constructed on a slope facing south and facing a road on the north side, was severely damaged by Typhoon No. 19. The plant is in the mountains of Izu Highland in Ito City, Shizuoka Prefecture. However, the plant is not listed in the report of accidents to the government.

The solar panel capacity on the entire area is estimated to be several hundred kW, but the plant consists of multiple low-voltage products adjacent to each other judging from the grid connection equipment. It seems that the plant is not legally required to report on-site accidents because of the situation.

Strong winds of Typhoon No. 19, which made landfall on Shizuoka Prefecture Oct 12, 2019, hit the southern slope, displacing panels from mounting systems and separating mounting systems with panels from foundations and turning them over. It is believed that many panels and mounting system parts were separated from the main body and scattered over the surrounding area because the mounting systems themselves were reversed and damaged (Fig. 9 & 10).

Fig. 9: Mounting systems with arrays turned over (source: Nikkei BP)

Fig. 10: Mounting system parts, as well as solar panels, scattered by powerful winds (source: Nikkei BP)

On October 15, when we visited the site, all of the panels and mounting system parts that were scattered were on the site, with some of them stacked in layers. However, panels and mounting system parts are also scattered on the road that faces the northern side of the project site in the images on SNS of the site immediately after the disaster.

Arrays (units for panel installation) are arranged in steps on a slope that roughly faces to the south at this plant. The damage was severe on the northern side (mountain side) near the road. There is a forest in front of the southern side (valley side), and it is possible that the forest weakened the winds.

The panels were arranged in four rows in a latitudinal direction and the arrays were comparatively large, which could be the reason why they lifted up like kites (Fig. 11 & 12).

Fig. 11: Damage apparently limited in area near forest on southern side (source: Nikkei BP)

Fig. 12: Possible that wind load increased because of large array area (source: Nikkei BP)