Visit to Plant

Solar Plant in Togane City Day After Being Struck by Typhoon

Cedar trees cut down in advance

2019/10/17 15:59
Shinichi Kato, Nikkei BP Intelligence Group, CleanTech Labo
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On September 9, 2019, Typhoon No. 15 hit and passed through Chiba Prefecture, Japan. This was the strongest-class typhoon in history among those to have struck the Kanto region.

The typhoon caused serious damage to central and southern parts of Chiba Prefecture. Buildings were damaged by being hit by other structures and trees blown down. Power outages occurred due to damaged electric facilities including steel towers, utility poles and cables, and water systems failed. Traffic was interrupted on roads and railways.

Solar power plants in this area could also be damaged by fallen trees and so forth. At a floating mega- (large-scale) solar power plant that utilized Yamakura Dam in Ichihara City, floating mounting systems were damaged causing a fire; news of this accident was extensively covered by mass media (See related article).

The "Exeo Togane Solar Farm," a mega-solar power plant with a solar panel capacity of about 2.6MW and a PV inverter capacity of 1.995MW in Togane City in the heart of Chiba Prefecture, was also badly damaged by the fierce winds (Fig. 1).

Fig. 1: Numerous fallen trees in surrounding area (top), Exeo Togane Solar Farm in Togane City, Chiba Prefecture (bottom) (source: top Nikkei BP, bottom Kyowa Exeo)

Kyowa Exeo Corp, a company engaged in telecom-related infrastructure, developed and operates this mega-solar plant. The company is approaching the power generation business in addition to engineering, procurement and construction (EPC) services for solar power plants, for which its knowhow in the mainstay business can be leveraged.

I visited the Togane Solar Farm for an interview Sept 10, 2019, the day after the typhoon struck the area.

No traffic lights were working on the roads around the mega-solar plant. Owing to the fallen trees that blocked the roads at many spots, I had to make my way to the power plant by searching for roads I could use. Reflecting the power outage at all the mobile phone base stations in the surrounding area, there was no mobile phone signal all the time I was at the power plant.

Despite such severe damage from the strong wind and fallen trees in the local area, the Togane Solar Farm was barely damaged.

The power generation facilities were neither blown away nor damaged at all, thanks to the array (unit of solar panels attached with a mounting system) structure consisting of robust foundations and mounting systems that can withstand winds above the expected standard value (Fig. 2). Apart from this typhoon, there has reportedly been no damage from strong winds at this power plant since it began operation in November 2016.

Fig. 2: No damage from strong wind thanks to robust foundations and mounting systems adopted (source: Nikkei BP)

The arrays, foundations and mounting systems were structured by Shinei Teck KK's concrete secondary products dubbed "H Pile" and Nisso Pronity Co Ltd's mounting systems. The plant had also taken measures against "falling trees" in the adjoining site. This mega-solar plant is in an area surrounded by forest and farmland in Togane City and had been categorized as forestland before the solar project. Kyowa Exeo set up the solar power generation system after permission was given by Chiba Prefecture to develop the forestland (See related article 2).