When storm-related power outages occur, we can feel the force of strong winds or witness the bolts of lightning that bring down tree limbs and power lines. But when it comes to an ice storm, the impact is not as obvious.
Often, the evidence behind the damage melts away before we see it.
When conditions are just right, as they were the morning of April 15, 2018, the precipitation falls through layers of warm and cold air causing it to become “supercooled” – not cold enough to snow, but not warm enough to rain. In this situation, precipitation freezes on contact, creating a heavy build-up of ice on power lines and tree limbs.
Just a ½-inch of ice can add 500 pounds to a span of power line. That’s the equivalent of stacking 50 one-gallon paint buckets on a span of line. Eventually, the added weight causes the power line to break, interrupting your electric service. The ice also makes the lines thicker, creating more surface area to catch wind gusts, intensifying its susceptibility to wind-related damage.
Power lines aren’t the only thing to fall under the pressure. Trees are also weighed down by the accumulation of ice, causing branches to sag and break, falling onto power lines and damaging electrical equipment. In some cases, the ice can have a slow effect, causing limbs to snap and fall long after the freezing rain has passed.
If the weather warms back up, the ice will melt and you’re often left wondering what caused the damage.
“Ice is sneaky,” said Rick Foltman, DTE Energy meteorologist. “It comes in, freezes over everything, causes its damage then disappears.”
So, why don’t we bury the lines? Wouldn’t that prevent us from experiencing weather-related outages?
It seems like a simple solution, but is certainly not a foolproof plan. While DTE has been incorporating more underground cables into the electrical system, and exclusively installing underground lines in subdivisions built after 1970, the cost to “underground” the entire existing system would be astronomical. An underground system is also not immune to weather-related power outages and has its own set of restoration challenges.
DTE is upgrading its electrical system in a variety of ways that will provide safer, more reliable power at an affordable price. This work includes installing new technologies, replacing and upgrading equipment, increasing the system’s capacity and trimming more trees.
Crews are continuing to work around the clock to restore power to the more than 370,000 customers impacted by ice storm Xanto.