Inspections entrusted to hotel

Kinden Corp provides engineering, procurement and construction (EPC) services at both mega-solar power plants next to Lake Biwa Marriott Hotel and on a former golf course in Izumizaki. PV inverters manufactured by Toshiba Mitsubishi-Electric Industrial Systems Corp (TMEIC) were adopted at both sites.

The mega-solar plant site of Lake Biwa Marriott Hotel is near the lake and is surrounded by rice and vegetable fields. These sites were beneficial in limiting construction costs because they were originally flat and required no full-fledged land reclamation. Mori Trust reportedly needed to do almost nothing apart from land leveling and weeding when it developed the site.

Given the badly drained ground, however, drainage measures had to be considered. There were originally reservoirs at multiple locations inside and outside the plant site. In order to use these reservoirs more effectively, new drainage ditches were dug so rainwater could be drained quickly and discharged into these reservoirs (Fig. 3).

Fig. 3: Drainage ditch and reservoir (source: Nikkei BP)

Even so, the site sometimes gets muddy in some areas especially on the day after rain. Accordingly, the company contrived a way to keep feet dry, placing concrete blocks and bricks like steppingstones in the areas that easily get muddy such as between arrays where people frequently walk for inspections and patrols (Fig. 4).

Fig. 4: Concrete blocks and bricks used like steppingstones (source: Nikkei BP)

The Mori Trust Group operates and maintains (O&M) the plant after it started operation. One of the group's characteristics is its extensive experience in building operation and management. According to Mori Trust, solar power plants are relatively easy to manage among the group facilities thanks to O&M that leverages this characteristic.

As for daily duties, the Mori Trust Group has established a structure to implement frequent patrols, requesting a security company to rush to the site when something goes wrong and entrusting daily patrols to the hotel. This was also meant as a safeguard against cable thefts from the solar plant. Such thefts have happened continuously in the Kinki region.

What has been entrusted to the hotel includes weeding. Although the solar panel areas are covered by crushed stones (Fig. 5), weeds have rooted and easily grow in some areas. The hotel cuts the grass in such areas.

Fig. 5: Plant site covered by crushed stones, large concrete foundations used (source: Nikkei BP)

The Mori Trust Group also applies the same O&M method that utilizes its resources to the mega-solar plant on a former golf course in Izumizaki.