Cooperative News

What causes outages on sunny days?

Six surprising power-interrupting culprits

We all know to brace ourselves for outages when thunder rolls, winds are high or winter storms blow in. But when the lights blink out on a sunny day, it can seem like a bolt out of the blue.

As our lineworkers and industry professionals can tell you, some things can cause outages even when skies are clear. Beyond lightning strikes and high wind, here are our top six outage-causing culprits.

Animal interference

bird icon

  • We’re used to seeing birds perched safely on power lines. But when large birds, squirrels, cats, snakes or other animals make contact between two energized lines or pieces of equipment, they create a fault, causing an arc that can knock out your power. (It’s no picnic for the animal, either!)
  • What we do to help: We place bird guards and other deterrents on our equipment. Unfortunately, very determined birds sometimes try to build nests in them! The guards also don’t protect against snakes climbing the poles, birds of prey dropping kills such as rabbits or fish on energized equipment or squirrels chewing on exposed underground wires. It’s a wild world out there!

Fallen trees

tree icon

  • Trees don’t only fall during wind storms. Dead or damaged branches can fall and take out a power line or utility pole even on a clear and sunny day, particularly if they’ve been weakened by recent high winds or weather events.
  • What we do to help: Our vegetation maintenance team works hard to keep our rights of way clear so our lines will be safe from debris. If you see a dead or damaged tree near a power line, let us know at 888-554-4732.

 Auto accidents

auto icon

  • Lights out on a sunny day? Tune into your local radio station for news about collisions — one of our top causes of fair-weather outages is auto collisions with utility poles or equipment serving underground utilities. Crop dusters, flying low to the ground, can also get tangled in lines and cause outages.
  • What we do to help: Our field staff complete hands-on safety trainings every year, including defensive driving, and avoiding accidents is one of our markers of cooperative success. But we’re just a small segment of vehicular traffic: When you’re driving, be sure to exercise caution and keep your eyes on the road.

Construction and landscaping accidents


  • Whether you’re building up or digging down, power lines are all around. Tall construction equipment like cranes and bucket trucks can clip lines, as can the raised beds of dump trucks. Excavating and digging projects can also damage underground electrical equipment, causing outages as well as the risk of shock or death to the user.
  • What we do to help: In addition to practicing awareness and safety in our operations, we provide member education about digging and construction projects on our website. Call us before beginning any construction project that will bring you within 10 feet of power lines, and call 811 before digging 16 inches or deeper.

Extreme temperatures


  • It may be a cloudless day, but if the temperatures are below freezing or extremely hot, your heater or air conditioner may be working overtime — and if all of your neighbors’ are, too, it can cause system overload, resulting in power interruptions. Extreme shifts in weather can also occasionally cause electrical equipment to malfunction.
  • What we do to help: We work hard to maintain and upgrade our system year-round to ensure peak electrical demand can be met and equipment is in good order. We also upgrade our substations to enable us to shift load when needed and backfeed power in case of outages.

Worn lines on the service side (between our system and your home)

energized line symbol

  • These issues at the point of service (such as your house) are generally issues of wear and tear, such as aging lines or damage due to tree limbs contacting lines on your property.
  • What we do to help: Our vegetation maintenance team trims trees on a 3-5-year cycle to make sure your tree limbs aren’t rubbing up against lines and equipment. Learn more about planting the right tree in the right place to help avoid outages.