Power outages are always big news, but I was a little surprised to see stories involving animal-caused outages lately. It seems our furry/feathered friends are responsible for a lot of power outages that not only damages expensive equipment, but kills the animal. Birds have the distinction of being the top contender for animal-caused outages, with one researcher estimating that birds could be responsible for up to 25% of power outages.
In addition to the customer’s issues associated with an unscheduled power outage, there are the costs related with repairing or replacing damaged equipment, but it doesn’t end there. Another report focused on the variety of regulatory fines and penalties associated with animal related outages that utilities can be facing. What’s more, if the animals involved were an endangered species, the fines increased substantially and included enforceable animal protection initiatives.
As I continued reading these papers and reports, it brought back a lot of memories for this ex-substation engineer. I learned early in my career that critter impact was an important consideration when it came to designing and building power grid facilities. Over the years, I have dealt with a variety of wildlife, and more than a few have been memorable encounters. One of the strangest, however, was an infestation of snakes and scorpions at one of my substation projects.
Protecting the Critters and Equipment
It happened at an elderly substation I had been assigned to modernize. I was told to meet the crew at the station, but to stay in my truck because this particular substation had a unique critter problem. That got my attention. The first work crew arrived, and explained there were snakes and scorpions inside the yard cable trench system and the control building due mostly to nightly temperature drops. They had a procedure in place that kept the humans and animals apart.
Upon arrival, the covers were removed from the concrete trenches. Once the covers were removed, the control building’s doors and pullbox lids were slammed many times. Then it was time for a coffee break, which gave the critters time to exit the building and trench system. This situation wasn’t considered a big deal because the creatures hadn’t caused any outages or harmed anyone. It would, however, be nice to make it safer for the humans. The fix was simple, high-density spray foam was used on all the openings in the control building and trench system.
Wildlife mitigation doesn’t need to be complicated. After personnel safety, there are two main categories when it comes to wildlife induced outages according to the experts. Those are bridging (i.e. phase-to-ground and phase-to-phase) and guano (i.e., insulation breakdown) pollution. Of these, the bridging grouping is most prevalent, and it occurs more frequently in medium and low voltage substations and overhead lines. Wildlife outage mitigation technologies have been steadily advancing.
Barriers have also improved. Hardware covers are using advanced polymeric materials to insulate conductors, bushings, bus work, and structural components in substations and on overhead lines. Equipment suppliers like Hubbell, TE Connectivity, Wesco, and others offer a wide variety of insulation for energized metalwork. Pre-molded covers and extruded polymer sheets for customed applications have proven effective along with understanding of animal behavior for better applications.
High-Tech Protection
In addition, there’s a wide array of high-tech devices that have also found their way into the battle of preventing flash-overs caused by animals. Ultrasonic devices emit noise above human hearing that scares small animals like mice, squirrels, and rats, which are food for predators. The high-pitched noise discourages them from living in or around the substation and its equipment. Since it’s inaudible to humans, there are no complaints from customers living close to the substation.
Another high-tech control method comes from BirdBuffer. They have developed a system using methyl anthranilate (MA) vapor barriers, which are invisible. MA is a naturally occurring plant-based compound found from grape skins, so it smells good to humans, but birds don’t like it. The MA vapor system temporarily irritates the birds in the substation and encourages them to move out of the facility without harming them.
Improving the power delivery system’s robustness and resilience is a major driving force when it comes to grid modernization, and protecting wildlife and power grid facilities is a key element. Studies reveal that roughly 90% of power outages occur on the distribution system, so reducing critter-caused outages is paramount. Wildlife can’t be kept out, but they can be protected!
