Over the past year, Oregon public power utility Eugene Water and Electric Board has been upgrading the Danebo Substation in Northwest Eugene. In August, EWEB completed the project, and the substation is back online, serving electricity to about 6,000 customers.
EWEB engineers have upgraded the substation to ensure new parts of the system are resilient to earthquakes and can meet rising energy demand.
For example, a large transformer might sit on a reinforced-concrete pad. The pad is designed for the transformer weight plus seismic forces, while welds secure the transformer to steel channels embedded in the pad. The pad is designed to resist sliding, overturning and excessive settlement.
Where needed, equipment foundations are deepened and widened to transfer seismic forces to stronger soil and rock deeper underground. Where appropriate, flexible connections, cable systems, and equipment interfaces have been installed to prevent foundation movement from transferring damaging forces between independent components.
EWEB installed a new transformer in the substation capable of delivering up to 65% more power than the previous transformer. This new capacity will give EWEB more flexibility in supplying customers during maintenance or unexpected equipment failures, maintaining reliability for years to come.
One example of improved safety at the substation is replacing the transformer insulating fluid with a natural ester fluid instead of mineral oil, which is certified as less flammable and readily biodegradable.
Balancing Infrastructure Investment and Cost
The Danebo Substation, like many of EWEB’s substations, was first constructed in the 1960s during an infrastructure boom that accompanied Eugene's rapid expansion. To address this aging infrastructure, EWEB is strategically modernizing substations over the next ten years.
EWEB noted it is working diligently to cut costs wherever possible to keep customer rates low, even as costs rise to maintain the grid.
Specifically, to manage costs, EWEB’s latest 10-year infrastructure investment plan defers rebuilding six substations by three to five years to manage rate impacts on customers. All told, the plan pushes back $65 million worth of work originally planned for the near term.
Substations change, or “step down,” high-voltage electricity from power generation stations to levels that can be safely distributed to power homes and businesses.
In total, EWEB has 38 substations in its electrical grid. The next substation planned for construction is the Jessen Substation.
Jessen will receive a complete rebuild like the Currin Substation, which was completed in 2024.
