Squirrels have caused three power outages in two years at one Versant Power substation. Here’s what the utility is doing to prevent more.
Monday, August 7, 2023
BANGOR, ME – On Sunday, October 9, 2022,
7,500 people in Bangor lost power. The culprit? A squirrel. A similar situation occurred two weeks prior at the same location. Versant Power, which serves customers in northern and eastern Maine, has since taken steps to prevent future squirrel-related outages by installing electric fences to keep the animals away.
This week, Versant Power line workers will energize one of these fences, which was installed around the Broadway substation on North Street in Bangor. The fence is a product of Transgard,
the leading animal-deterrent fencing for electrical substations. In cases where a squirrel encounters electrical equipment at a substation and causes an outage, it is electrocuted. This fencing solution delivers a humane and effective electric shock that deters climbing animals before they can enter more dangerous areas.
"In suburban areas, there are always a lot of squirrels, and for some reason this substation has been a magnet for them,” said Power Systems Technical Supervisor Riley McKay, the project manager for the fence installation.
Squirrels, birds, and snakes are
a leading cause of power disruptions. In Maine, trees are the primary cause of outages, but squirrels especially become an issue in autumn as their activity increases in preparation for winter. At the Broadway substation alone, three separate squirrel-related power outages have occurred over the last two years, leading to 20,000 customer outages.
When a squirrel spans an insulator and touches both an energized conductor and a grounded structure, or two different phases of energized conductors, the squirrel creates a fault path. This causes a surge of fault current. Fault current can cause extensive damage to substation assets. Versant's protective equipment senses the fault current then operates to protect both substation assets and downstream customers, resulting in a power outage.
The Tibbetts Street substation in Brewer also experienced several squirrel-related outages in 2017, 2019 and 2020 – this was before the company installed their first Transgard fence on a pilot basis in May 2021. Since that time, there have been no squirrel-related outages at that substation.
“In potential sites we look for the space between the substation fence and the structures, and we look for overhanging structures as well. You can’t prevent all the squirrels from getting in, but we’re hopeful this will help based on how effective the fence at the Tibbetts Street substation has been,” said McKay.
The new electric fences are located inside exterior fences that are not electrified, ensuring the public cannot come in contact with them. Versant also installs squirrel guards at all distribution substations, which makes the electric fences an added layer of protection. Following the success of the pilot program, McKay noted that the company plans to install more fences around substations to improve reliability for customers.