General

Cass to Sarpy Transmission Project supports reliability, communities

OPPD has entered the transmission building stage on what is likely the largest and most complex joint transmission-distribution project in the company’s history. 

The transmission build kicks off this week, but distribution work on the Cass to Sarpy Transmission Project has been underway for the past several months. The line runs between OPPD’s Cass County Station and the new Turtle Creek Station in Sarpy County. 

The new 23-mile, 345 kilovolt transmission line supports community growth. As part of the transmission build, OPPD had to move existing distribution lines because they would conflict with construction of the transmission lines or they lacked the required clearances between transmission and distribution wires.  

The project opened up an opportunity to create a comprehensive plan for the area to increase reliability and support growth for the long term, including placing distribution wires within the transmission corridor – something OPPD hasn’t traditionally done. 

“What we built is inherently a more reliable system,” said Lead Engineer Tyler Knuth. “We also built a larger infrastructure so we can expand and grow with the community.” 

Strengthening the grid

The communities in OPPD’s service territory are thriving, and the utility is working to accommodate load growth across all types of customers.  

In addition to the transmission project, OPPD is adding three new dual-fuel combustion turbines at Cass County Station. The units can be brought online quickly to meet sudden spikes in electricity demand. Two natural gas units already at Cass County Station will be converted to dual fuel generators. That will allow them to run on either natural gas or fuel oil as a backup.  

To the north in Sarpy County, OPPD brought two new dual-fuel generation units online at Turtle Creek Station this summer, and broke ground for the addition of a third unit. 

The natural gas stations are vital for reliability in the winter, when demand is at its highest. The ability to use multiple fuels bolsters reliability and gives OPPD more flexibility with its operations. 

Supporting long-term growth

The opportunity to place distribution wires within the transmission corridor allowed OPPD to invest, where possible, in underground distribution lines, making it less likely that OPPD will have to move the distribution lines in the future for road work. 

Distribution lines are typically placed in the city or county right of way. That meant OPPD’s Distribution Engineering team worked closely with OPPD’s Right of Way team and Transmission Engineering team to site the new distribution lines. 

Less than 10 percent of the new distribution lines will be overhead. The overhead portions will mostly be some backbone distribution lines that carry power along county roads or through the city of Louisville. The distribution lines will attach to transmission poles to send electricity over the Platte River. 

OPPD and contractor crews have been installing manholes, switches and conduit for the underground distribution. The distribution side of the project will be completed after the first of the year. 

“We’re creating a system that will be in place for a long time,” said Distribution Engineer John Tomasek.