Sharing the transmission grid with storks and other birds

摘要

Sharing over-head lines [OHL] with birds requires significant efforts and third party engagement before lines are erected and afterwards as well. The authors show how regular inspections followed by automatic signal processing and data abstraction followed by criticality analysis and model validation with grid events records carry the concern about bird wellbeing across all stages in the life of an OHL. The stork (in particular, the white stork) is perhaps the most visible of the concerns of REN - Rede Electrica Nacional, the Portuguese Transmission System Operator [TSO], with the environment and, in particular, with birds. This species is one of the disturbing agents of the proper functioning of OHLs, especially near the estuaries of Tagus, Mondego and Sado rivers, which led to the search for solutions that minimize interactions between birds and operation of the Portuguese Transmission Grid that are detrimental to both. The main problems are due to the accumulation of droppings in insulators, producing a conductive path and the construction of nests, whose materials (whose size can get close to 1 meter) fall and stay hanging on insulators. Every year, REN invests in actions to mitigate the effects of the presence of storks on OHL. The main measures include the installation of anti-landing devices ("anemometers") on critical towers and over insulators strings, and nest transferring for special platforms in more favorable points of the towers. For these measures to be effective, it is necessary to know where the nests are located (geographically and locally in each tower). For this, REN commissions an airborne inspection dedicated to the counting and location of nests. The authors regard the sharing of the electrical infrastructure with storks as a multi-disciplinary subject and reveal mitigation measures and other stork-related activities that contribute to improve the knowledge of the storks' life cycle and their acceptance as convivial neighbours on the transmission grid and expect most of the methods to be adaptable to other voltages, territories and bird species.