Solar Plant Leverages Lessons From Thunderbolt (page 3)
Cost-cutting efforts include weeding measures
The solar panels were installed with the lengthwise rows limited to two panels (Fig. 5). If the lengthwise rows were increased to three panels, a more-costly mounting system would be required due to a heavier load caused by the stronger wind pressure that the mounting system has to endure. In addition, the construction and maintenance costs would rise due to the higher edge of the panels. Furthermore, the construction cost was also lowered by the deployment of metal pile-type foundations, instead of concrete foundations, that support the mounting systems.
Stronger protection from thunderbolts in light of damage at Kasama
Daiichi Jitsugyo also enhanced the protection from thunderbolts. In May 2013, part of the solar power generation facility was damaged by thunderbolts around the area, and the amount of power generation sharply decreased for about a month at Kasama Solar Power Plant.
This was because part of the substrate embedded with the core components in the PV inverter was damaged by the high voltage that reached beyond the designed value and ran through the transmission and distribution cables following the thunderbolts.
Fortunately, the damaged area was limited, and the plant could continue to generate power even though the output declined. The amount of generated power recovered every time the substrate was replaced. Based on this experience, Daiichi Jitsugyo decided to add the surge protective devices (SPD) to all the cables and circuits connected with the PV inverters from the construction phase.