Riding-type grass cutters have begun to be used widely in O&M (operation and management) of solar power plants. They are used at many solar power plants throughout Japan.

Riding grass cutters that are different from conventional ones began to be used recently for removal of grass on solar power plant sites. Riding grass cutters that are generally used at solar power plants are shaped like go-carts, and rotary blades are mounted and enclosed between four wheels directly below the driver's seat. The new-type riding grass cutter introduced here is designed differently, and rotary blades are extended frontward from the vehicle body (Fig. 1).

Fig. 1: Rotary blades in front of vehicle body (source: Wado Co Ltd)

It was difficult to cut grass very close to foundations and fences or under lower sides of solar panel arrays (units for fixing solar panels on mounting systems) using conventional types of riding grass cutters. Portable-type grass cutters are normally used to cut grass in such areas.

The riding grass cutter introduced here can cut grass very close to structures, and grass growing between panels and the ground can be cut by sliding the cutters in the space between them. In other words, the cutter features both the accessibility of portable grass cutters for structures and the efficiency of riding grass cutters.

The accessibility was improved by extending the rotary blades to the front. The blades are in the front and far from the driver's seat. This design was to minimize damage to trees in the event of the rotary blade unit contacting trees to protect trees at orchards from being damaged. Therefore, it is safe to cut grass by approaching close to structures.

When a portable grass cutter is used, the operator, who carries the cutter using a belt on the shoulder or waist, can rotate the rotary blade, which is away from him/her by a certain distance. An advantage of the portable grass cutter is that the operator can approach structures while cutting grass. However, grass cutting at large-scale solar power plants puts a great strain on operators. Grass cutting by portable grass cutters is time consuming, because the operation efficiency per area is comparatively low, and it is not realistic to only use portable grass cutters.

However, portable grass cutters are frequently used in certain areas at solar power plants where riding grass cutters are used. This is because it is difficult to cut grass directly beside structures by conventional riding grass cutters. Portable grass cutters are used to cut grass remaining in such areas.

If a riding grass cutter featuring the advantages of both types is used, areas where portable grass cutters are used will be reduced and the efficiency of grass cutting will be improved.

The grass cutter is driven easily under the arrays at a solar power plant in Hokkaido, for example. As you can see from the video, women who are normally unfamiliar with machines can use the cutter easily, because the rotary blades can be operated easily using the lever near the operator.