Visit to Plant

Solar Plant on Former Eel Farm Avoids Floods But Suffers From Weeds (page 3)

Weeding implemented in line with local events, vehicle-type weed cutter utilized

2019/08/16 10:59
Shinichi Kato, Nikkei BP Intelligence Group, CleanTech Labo
Print Page

Considerations paid to neighboring area even when planting trees, weeding

To prevent the solar panels arrayed across the site from giving a rather lifeless impression to those who see the mega-solar plant from within the housing complex, trees were planted along the fences in the areas adjoining the housing complex (Fig. 3).

Fig. 3: Trees planted in consideration of housing complex. Compared with bottom photo shot in November 2015, trees have clearly grown (source: Nikkei BP)

As about three years and 10 months have passed since the operation began, the trees have grown and are suppressing the rather lifeless impression as expected. In addition, the plant implements weeding in the site near the housing complex shortly before the large-scale cleaning of the ready-built houses twice a year. The company weeds the solar site in order to give the same clean impression when the housing complex is cleaned and becomes cleaner than usual.

At the Kurimamachiya Mega Solar Power Plant, the weeding frequency has increased more than expected around arrays. Sanko Real Estate was planning to weed the site twice a year; however, weeding is needed at least four times a year, perhaps due to the site being a former eel farm (Fig. 4).

Fig. 4: Vehicle-type weed cutter utilized in site, vines on fences removed manually. Fences on river side (lower side in middle photo) covered by vines and blocked like walls with no open spaces. Measures taken to remove vines on fences at mega-solar site (bottom photo) (source: Nikkei BP)

As Sanko Real Estate, unlike the companies which operate a few power plants at remote locations, runs solar power plants at 24 locations in its home base Mie Prefecture, it can increase weeding efficiency by intensively weeding multiple power plants in series as planned, for example.

Sanko Real Estate adopted vehicle-type weed cutters ahead of industry peers and later an additional machine, which features a higher cutting height and is more suitable for use at solar power plants, to further boost work efficiency.

At Kurimamachiya Mega Solar Power Plant, with a site area of about 5ha and a solar panel capacity of roughly 4.5MW, it initially took four to five hours to weed the site using two weed cutters at the same time. Compared with the conventional strimmers, even this was a significant improvement in efficiency. By using a new vehicle-type weed cutter that features a higher cutting height, however, weeding now only takes four hours with one machine (Video).

Video: Cutting weeds by vehicle-type weed cutter with higher cutting height (source: Nikkei BP)

Partly because the operator is getting used to the operation of this vehicle-type weed cutter, the new model's characteristics are contributing to improving work efficiency. The weed cutter not only features higher cutting height, but also allows operators to raise and lower the cutting height just by shifting a lever while driving. These two characteristics reduce the risk of hitting crushed stones and other objects, so the number of times the operation stops or slows down decreases.

The lower risk of hitting crushed stones has also led to improved safety, namely the lower risk of injuring workers and damaging solar panels.

Facility overview