Interactions between Electrical Infrastructure and Wildlife

Such interactions can have fatal impacts on avian populations if mitigation measures are not taken. Several categories of international/national legislation and guidelines are in place to deal with these issues. Beyond the impact of electrical infrastructure on birds, wildlife interaction with electrical infrastructure in general can also result in electrical incidents, with significant costs for the TSOs and DSOs either on overhead lines (OHL) or in substations.

In order to better understand these problems and review solutions, a CIGRE Working Group named “Wildlife and electrical infrastructure” was set up in 2016. The working group focused on studying the interaction between birds and power lines. Thirteen countries were directly involved and remained active members of the Working Group (of which nine are located in Europe), with fruitful cooperation. The Working Group involved mainly TSOs (ten TSOs and one DSO), as well as other categories of participants (universities, research centers, consultants and administrators).

As a result of the Working Group, a Technical Brochure (TB) was produced, divided into 8 chapters. Appendices are also provided and give more details on each chapter.  

Chapter 1 introduces the subject and gives an overview of the legal background, factors of collision and electrocution, the main impacts of wildlife on the electrical infrastructure and the main relevant resources (international guidelines) on the issue.

Chapter 2 of the TB shows that electrical utilities are taking more and more wildlife aspects into account, first to obtain the necessary permits but also to improve their environmental responsibility (Corporate Social Responsibility), beyond just legal compliance. Companies are providing more effort in working with associations, universities, scientists and perform studies on the topic. These studies demonstrate that environmental protection is an important subject for electrical utilities.

Chapter 3 deals with the impact of wildlife on new infrastructure projects. The TB shows that impacts related to wildlife are considered as significant for a project. Impacts on wildlife can lead to delays, rerouting or even the cancellation of a project. At a national level the problem of OHLs and bird collision and electrocution is almost entirely addressed within SEA (Strategic Environmental Assessment) (although in some countries not always a legal obligation) and EIA (Environmental Impact Assessment) procedures and associated reports. Protected areas and species have a significant impact on the routing of new OHLs. Methodologies to perform SEA and EIA on wildlife issues are described in the TB and can include guidelines (external or internal to the utilities), GIS (Geographic Information System) maps and the assignment of consultants. The TB shows that the results of the environmental studies can lead for example to local rerouting of the line, the installation of Bird Flight Diverters (BFDs) and more rarely to change the diameter or the configuration of wires, to remove a shield wire, to change tower designs or to bury lines. 

Chapter 4.1 deals with the subject of bird collision with existing infrastructure and shows that it is particularly difficult to quantify these events (as opposed to electrocutions) because a wire strike does not typically result in electrical incidents which can be monitored and counted. Additionally, there are several biases associated with carcass searches, which is a primary indicator used to assess bird mortality. The TB shows the examples of...