Last month, I gave an overview of the transmission system serving Curry County. The Anvil fire was burning southeast of Port Orford and had potential to threaten the Bonneville Power Administration transmission lines that power the southern end of the Coos-Curry Electric Cooperative system. After reading my article last month, one co-op member reached out to ask me how Coos County is served from the BPA transmission system. It’s a great question, because the transmission system that serves Coos County extends south to serve Curry County.

So, I’ll back up and explain more about how CCEC receives the electric energy that powers our lives. Most of the electricity CCEC receives is generated by the Columbia River federal dams. After being generated, the electricity is transformed to high voltage and injected into what is called the bulk electric system. The BES is the electric equivalent of the road system’s freeways and highways. It moves large amounts of electricity over long distances. The Oregon south coast connection to the BES is at BPA’s Fairview substation via two 230 kilovolt transmission lines.

Transmission lines in the Northwest BES are typically operated at 500 kV, 230 kV or 115 kV. Higher voltage lines can move more energy and are built to more robust standards, like the difference between freeways and highways. The two 230 kV lines delivering power to Fairview in Coos County follow a common corridor south from the Eugene area and west from the Roseburg area. One of these lines is suspended from steel structures and the other from wood and steel structures. Either line can be out of service without interruption to CCEC’s power supply. In this way, CCEC’s power source is redundant because either of these lines can carry the entire CCEC load. Also, because both lines are built to more robust 230 kV design and one is entirely on steel structures, CCEC’s power source is quite resilient. BPA does a great job controlling vegetation in its transmission line corridors, which minimizes fuel load and increases resilience from wildfire damage.

The two BPA transmission lines I wrote about last month originate in Fairview and end in Gold Beach. CCEC’s distribution substations tap into the 115 kV transmission grid.

Large substation transformers convert the electricity to distribution voltage, typically 12.5 kV. The CCEC distribution network 

of overhead and underground power lines extends from the substations to homes and businesses, powering our lives.

In a coming month, I’ll give an overview of what CCEC does to build redundance and resilience into our distribution system.

Happy Thanksgiving!

Brent Bischoff General Manager and CEO