Siemens has been chosen by Yellowstone Electric Co. out of Billings, Montana on behalf of the US Bureau of Reclamation, to deliver 14 environmentally-friendly ester insulated power transformers to Glen Canyon Dam power plant in Arizona.

The ester fluid, derived from alternative oils, offers significant environmental benefits to the petroleum-based mineral counterparts typically used in power generator step-up transformers. This fluid is fully biodegradable, operates at a much higher flash point which results in a lower fire risk and can dissipate in water quickly if necessary.

The new transformers will replace equipment installed for the dam’s initial operation in 1964 and will increase real power transmission capacity. The power infrastructure upgrade will allow Glen Canyon power plant to continue its annual production of approximately 5BkWh for 5.8M customers.

Supplied by Siemens factory in Linz, Austria, the ester fluid transformers are rated at 125MVA (ten units designed for 345-kV and four units for 230-kV). They will connect Glen Canyon’s generation units to the transmission grid and increase power capacity to provide stable and reliable electricity to customers. This is the first time the Bureau of Reclamation will use ester fluid transformers of this size for a hydroelectric power project.

“Hydroelectric generation is our nation’s largest producer of renewable power, so we need to ensure the systems that support this integral resource are operating efficiently and reliably while keeping environmental and sustainability concerns at the top of our minds," said Richard Boyd, vice president of Siemens Transformers US. "Our goal in working with the Bureau of Reclamation and Yellowstone Electric was to address these issues, and we’re proud that our new ester fluid transformers will enhance the integral power infrastructure for the dam and do so in the most environmentally conscious way possible."

Siemens will begin delivering the transformers in late 2017. The units are expected to be installed and begin operation in 2018 and 2019.