According to the preliminary report released by the Ministry of Economy, Trade, and Industry (METI) of Japan, the incident was due to anchor failure.
The island itself was held by 420 anchors and 823 mooring lines in place and during the typhoon, 7 anchors on the southern side of the island came loose.
According to METI one of the possible reasons is that on the day of the typhoon, the water level was 37.3 which is close to the maximum water level that can cause high tension on the mooring lines.
According to a Ciel et Terre representative, “The [mooring] lines are installed under tension at high water level, while usually water level does not reach high water level, the lines have slack,” and because of wind and waves it might have caused the accident but METI did not draw any conclusions.
The shape of the plant was involved too, anchors and mooring lines are attached to the outermost floats and the fixed floats are attached by resin bolts. After the failures of the anchors, the pressure of the floats was on the resin bolts. These caused the bolts to collapse in a chain reaction which led the plant to be torn apart in three pieces.
The Shintaku Tameike floating PV was also destroyed in a similar way. Due to this some of the panels went up and on to each other, this caused panels and other equipment to short circuit. The short circuit caused the plant to burst into flames. So it is better to be more cautious about the exact effect of winds on floating solar PV installation until it is more apparent, to reduce more accidents like this in the future.
Source:@ pv-magzine & @Solar_Edition
Photo:@ Yahoonews @Solar_Edition
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