EE 392 Stewardship Transmission Towers, Power Lines & Birds David Dukes Michael Harper

Basic Facts  Not only costly to birds but costly to power companies  Actual statistics on bird death are hard to calculate  US Forest Service estimates power lines to kill hundreds of thousands to 175 million birds per year  10.7% of line outages are due to birds  60% of bird deaths are from collisions with the overhead shield wire (OHSW) or optical ground wire (OPGW)  Power lines are estimated to electrocute tens of thousands to hundreds of thousands annually  Most of these electrocutions occur on distribution lines as opposed to transmission lines as the phases are spaced closer together  Birds like to use transmission structures as perches. It is common for osprey to build their nests on these structures.

Prevention Methods  Perch Preventers  Flight Diverters  Nesting Platforms  Spiral Vibration Dampers (SVDs)  GreenJacket Cover Up  Removal of bird trap structures

Zena Bird Perch Preventers  Prevent birds from perching and nesting on power structures  Reduces bird deaths  Reduces power outages  Environmentally friendly  Zenadesign.com

FireFly Bird Flight Diverter  Reflective tag hung on OHSW or OPGW to increase visibility  Can also be installed on side guys and bridle guys  Glows in low light conditions for up to 12 hours  Rotates on the line in the wind  Installed live  Pr-tech.com

Preformed Bird Flight Diverters  Increases visibility to reduce the number of bird collisions with power lines  Installed on OHSW or OPGW for high voltage applications  Can be installed directly on live conductors in low voltage applications  Also acts as a damper to reduced vibrations in the line  Preformed.com

Nesting Platforms  Separate structures built away from power lines give birds a safer place to perch and nest  Similar designs to the one below have been made in which bird or even owl houses can be hung from the structure  Often constructed from salvaged power line material to cut costs

Bird Trap Structures  Power structures like the one to the right are dangerous for birds  This design is mostly seen on distribution lines or lower voltage transmission lines (69kV)  Birds can perch on the lower cross arm and when they fly away are at a greater risk of colliding with 2 of the higher phases  Removal of structures like these will lead to less bird electrocutions  Alternative designs have been created

Cantega GreenJacket Cover Up – “It fits”  20% of substation outages are caused by wildlife prior to installation  After installation outages and wild life fatality were greatly reduced  Offers a solution to cover up energized areas in substations  Standard cover up available or they will come to your substation and provide a custom solution based on your needs  Live Installation  Cantega.com

References -AltaLink ( -US Forestry Department ( -Cantega Industries ( -Preformed Line Products ( -PR Tech ( -Zena Design ( -Analysis of Factors Contributing To Unexplained Transmission Line Faults on a High Voltage Transmission Network (Bekker, Hoch)Analysis of Factors Contributing To Unexplained Transmission Line Faults on a High Voltage Transmission Network