SYMPOSIA PAPER Published: 01 January 1989

Assessment of Squirrel-Caused Power Outages


Squirrel-caused power outages in Lincoln and Omaha, Nebraska, were evaluated by examining company power outage reports and by consulting with power company representatives. Reports showed that squirrel-caused outages at pole-mounted transformers were most prevalent during May, June, and October (48% of total) and between 1 and 4 h after sunrise (38%), patterns that coincide with squirrel dispersal or morning activity periods. In Lincoln, 1980 and 1981, squirrels caused 177 outages per year, which was 24% of all outages and 90% of animal-caused outages. Estimated minimum annual costs were $23 364 for repairs, public relations, and lost revenue while meters were not running. In Omaha, 1985 and 1986, squirrels caused 332 outages per year, costing at least $47 144 annually. Squirrel-caused outages at substations cost an additional $400 (Lincoln) to $810 (Omaha) annually. Between 1982 and 1985, squirrel guards were installed on all 13 000 Lincoln transformers at an estimated minimum cost of $20 per guard, or $260 000 total. Records from Lincoln after all guards were installed (1986 and 1987) indicate that annual costs were reduced 78% to $5148. Life expectancy of the guards is unknown. The extent of squirrel-caused outages and associated costs may vary among cities and regions. Assessment of these outages as described here can be used for timing biological studies and as a procedural structure for making similar economic assessments in other areas.

Author Information

Hamilton, JC
University of Nebraska, Lincoln, NE
Johnson, RJ
University of Nebraska, Lincoln, NE
Case, RM
University of Nebraska, Lincoln, NE
Riley, MW
University of Nebraska, Lincoln, NE
Price: $25.00
Contact Sales
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Developed by Committee: E35
Pages: 34–40
DOI: 10.1520/STP25259S
ISBN-EB: 978-0-8031-5103-1
ISBN-13: 978-0-8031-1281-0