The modernised McKenzie and Valhalla substations are owned respectively by Chelan County Public Utility District (PUD) and the Portland (Oregon)-based Bonneville Power Administration (BPA).
However, the Chelan County PUD has used part of the funding it received from Alcoa to buy outright the 'low side' of the Valhalla substation, making Chelan the primary electricity supplier for the Wenatchee smelter.
A Chelan spokesperson told Aluminium International Today, "We have purchased the low side of Bonneville Power Administration’s Valhalla Substation to integrate with our own McKenzie Substation to provide transmission service to the Alcoa plant for the power they purchase from us under a wholesale power contract, which is for a “slice” of our production – not a guaranteed amount. Alcoa also purchases power from the market as needed when the amount we produce is not sufficient for their operations. Alcoa paid for the substation and all the associated work."
Chelan PUD manager George Velazquez told the Wenatachee World website that both substations were now working and that they had to remain active throughout the overhaul process in order to maintain a power supply to the smelter's potlines.
During the overhaul – which brought together Chelan PUD, Alcoa and BPA – some of the parts replaced at both substations were over 60 years old.