Flashlight Repels Crows at Solar Plants (2)

2017/10/02 10:52
Shinichi Kato, Nikkei BP Intelligence Group, CleanTech Institute
Print Page

Continued from Flashlight Repels Crows at Solar Plants (1)

Develops devices to prevent nesting on telephone poles

Toshin Electric is a manufacturer of wiring materials for power, railway and telegraph equipment. As part of its business operations, the company has been working on measures to prevent problems caused by crows nesting around wires.

The development of the devices incorporated by Obayashi was started in 2010. The purpose of the devices was to prevent nesting on utility poles that support transmission lines of power companies (Fig. 3).

Fig. 3: Examples of installation on utility poles. Developed to prevent crows nesting (source: Toshin Electric)

Crows use a variety of items to build nests. They even use metallic items such as clothes hangers. If a metallic item contacts a nearby power line, a power line ground fault may occur. The devices were developed responding to requests of power companies that want to efficiently prevent such accidents.

Crows build nests in the months from February to May. Nests are built nearly every year on utility poles, which are suitable for such nests. Power companies remove the nests as soon as they find them, but the frequency of this operation can be reduced if measures that make crows give up nesting are worked out. However, methods that have negative effects on the environment, creatures and humans in the surrounding areas cannot be incorporated.

Beams were conventionally used in airplanes as measures against bird strikes, which is when birds are sucked into engines. To prevent such accidents, strong beams are flashed to keep birds away from airplanes.

Toshin Electric decided to incorporate this system to develop a device that reduces the frequency of nesting by emitting flash beams from LED lights, which crows dislike.

The devices are installed on utility poles and cannot receive power from external power sources. It is better that they are small and light. Crows build nests in the daytime only, and beams need to be emitted in the daytime only.

Therefore, a combination of a solar panel and an electric double layer capacitor is used as the power source to realize independent operation without relying on external power sources. The solar power is stored in the capacitor to emit beams in the daytime (Fig. 4).

Fig. 4: Illuminated by the independent power source in the daytime. Crows build nests in the daytime only and beams are not emitted at night. (source: Toshin Electric, partially modified by Nikkei BP)

Power consumption for operation needs to be reduced to downsize the external dimensions. The flash beams are emitted upward because the targets are crows in the sky.

The first prototype units were manufactured in 2010, assuming installation on and removal from utility poles in and around months from February to May when crows build nests. In cooperation with a power company, the devices were installed for testing on utility poles at two locations where crows frequently build nests. As a result, no nests were built on the utility poles, proving the effectiveness of the devices.

Prototype units with different flash beam angles and LED luminescent colors were manufactured in 2011 and were tested by a similar method. They were installed, selecting utility poles at 12 locations as the targets, and nesting was eliminated after installation.

In 2012, the third year, prototype units manufactured by reflecting the experiences of the previous year were installed at 37 locations. In this year, seven nests were built after the installation. The devices at these seven locations were installed in places with objects that shield the beams and failed to fully produce the effects, according to the company.

It was evaluated that the method produces a higher effect compared with conventional methods based on the results, and a number of power companies incorporated the devices after commercialization of the products.