Visit to Plant

24MW Solar Plant Overcomes Barriers of 'Farmland,' 'Output Fluctuation' (page 4)

2019/11/06 16:16
Kenji Kaneko, Nikkei BP Intelligence Group, CleanTech Labo
Print Page

Supporting posts' added against snow cover

As Shiriuchicho faces the Tsugaru Strait through which a warm current flows, the town is considered to be one of the easiest places to live in Hokkaido, with the highest temperature in summer reaching no more than around 30°C and the lowest temperature in winter falling no lower than about -10°C. In terms of snow cover, the highest snow cover reaches about 50 to 60cm, which is relatively low in the north.

Accordingly, sufficient consideration was given to measures against snow cover when designing the mounting systems and arrays (unit of solar panel installation) at the mega-solar plant. Because it is difficult to remove snow that accumulates on the panels at a power plant as large as one with 24MW output, the panel installation height and angle were increased so the snow would easily slip off the panels.

Each large-area array basically consisting of eight panels in four rows (eight panels sideways, four panels lengthwise) was tilted by 30° so the snow on the panels would easily drop off. As a result, however, snow would pile up in front of the arrays more easily.

If the banks of snow under the arrays grow high enough to reach the panels, the snow on the panels would no longer fall off and could cause damage to the panels and mounting systems because of the gravity that pulls melting snow on the panels downward. Given these circumstances, the lowest parts of the arrays were positioned 1.5m above the ground to prevent the snow banks from reaching the panels.

In preparation for the risk of snowbanks reaching the panels due to more snowfall than usual, supporting posts for reinforcement were set up in the front row of the arrays. They help the panels and mounting systems withstand the downward pulling force caused by the weight of snow and melting snow (Fig. 7).

Fig. 7: Supporting posts added to front row of arrays as measure against snow cover (source: Nikkei BP)

Facility overview