General

OPPD expanding air-flow spoiler use to help prevent galloping lines

One thing the Great Plains has plenty of is wind. That is positive for producing wind energy, but wind can also sometimes cause damage.

Wind, especially wind gusts, can wreak havoc on everything from roofs to awnings to power lines, and when ice enters the mix, the result can be widespread power outages caused by “galloping” power lines.

One way OPPD combats that problem is by installing air-flow spoilers on some power lines across the district.

Ice effect

When ice forms on power lines, it creates an aerodynamic teardrop shape, which can lead to galloping. The added weight on the line pulls it down, and when winds blow at 15 mph or higher, the lines bounce and sway — sometimes as much as 2 or 3 feet. Galloping lines can cause disruption or outages when they swing and contact each other or when electricity jumps between two lines that come near each other.

Galloping lines can also weaken or break poles that hold up the lines. Damaged poles can cause outages and dangerous downed wire situations. Galloping mostly happens in rural areas, but occasionally occurs in urban areas, too.

Air-flow spoilers help prevent galloping. They are rigid thermal plastic coils that wrap around sections of power lines and prevent wind from flowing smoothly across the lines, which stops the kind of movement that makes line gallop.

New areas

Later this month OPPD is installing airflow spoilers on sections of 69 kilovolt (kV) transmission lines in some rural areas.

The areas where work is soon starting run from Louisville to Weeping Water and from Weeping Water to Elmwood, said Josh Verzal, manager of Transmission Engineering at OPPD.

Some of these areas experienced outages or “blips” in service.

“We don’t like to see it (outages caused by galloping) at all,” said Verzal. “But these are areas that are prone to it.”

A total of nine miles out of a 21-mile span of 69 kV line will have air-flow spoilers installed. They are placed about 15 feet apart and are only placed on lines running east and west, due to wind patterns in our area. We don’t typically see galloping on lines running north and south, Verzal said.

Ongoing work

From this summer until the end of 2024, more lines, including some 161 kV lines, will also have air-flow spoilers installed.

Two areas identified for installations this summer are around Brock in Nemaha County and around Tecumseh in Johnson County. OPPD will use a specialized contractor who does “hot” work — maintenance on live wires — for those areas.

“This should reduce outages in rural areas and improve power quality for our customers,” Verzal said. “It also eliminates light flickers and service interruption.”

Types of power lines

OPPD also puts air flow spoilers on distribution lines. So, what is the difference between the two types of lines?

Distribution lines are found chiefly in neighborhoods and business areas. They take power from substations and feed homes, schools, apartment buildings and most businesses with lower-voltage electricity. The power levels are “stepped down” at substations and through the transformers – typically the green boxes found in backyards or around businesses.

Distribution lines are on the smaller power poles that often carry telecommunications wires. In newer developments, distribution lines can be buried.

Transmission lines are the more prominent, thicker lines on large structures in rural areas or even near interstates. They carry power from the generating stations to substations across the region at much higher voltages—from 69 kV to 345 kV on OPPD’s system. Transmission lines also connect different utility systems and ensure power is flowing on the nation’s power grid as designed.