Abstract
Norway has approximately 165 000 km of overhead power lines in the distribution grid system, thus numerous structures are representing a high electrocution hazard to birds. With its long coastline and scattered human population, a significant part of the grid is located in marine environments with high air salinity. The same area represent a stronghold for the eagle owl (Bubo bubo), a Norwegian red-listed species. A research project within the Center for Environmental Design of Renewable Energy (CEDREN) identified high electrocution-risk structures for the eagle owl and other coastal species in Central Norway. As a part of the project, corrosion tests were made to estimate the lifetime expectancy for conductors equipped with insulating bird protection systems and compared the results to those from bare conductors. The experiments simulated 24 years of exposure in marine environments with corrosivity indices of 4 and 8. It turned out that there was a lifetime expectancy reduction between 12% and 22% for conductors with insulators compared to bare conductors. To protect the eagle owl in flat coastal landscapes, where pylons are used as hunting posts, also alternative solutions were searched. A successful option was an elevated prolongation of the cross arm, offering the birds safe perching opportunities. The new device was manufactured and tested in field, and can now be deployed by grid owners as an alternative to insulation systems in areas with eagle owl populations at risk.
