On Tuesday the New Ulm Public Utilities Commission (PUC) authorized an engineering services contract with PSE, Inc. for the replacement of Center Street substation transformer.

Utility Planning and Development Engineer Dan Pirsig said this transformer was built in 1968, making it the oldest one on the New Ulm system. It has been modified with oil coolers and fans since its initial installation. The transformer is currently working without issues, but due to its age staff would rather replace it before there is a problem.

It is estimated to take two years for the replacement transformer to arrive. Pirsig said the old transformer will be 60 years old by the time it is replaced.

The transformer is not currently used every day, but it is tied directly to New Ulm’s Midcontinent Independent System Operation (MISO) generation.

The oldest substation transformer on New Ulm’s electrical system is set to be replaced by 2028. New Ulm Public Utilities Commission authorized engineering services with PSE, Inc. for the replacement of a Center Street substation transformer, originally installed in 1968.

MISO provides transmission and monitoring of the high-voltage transmission system in the Midwest United States Manitoba, Canada, and the southern United States. New Ulm’s power plant is connected to the MISO market and is capable of supplying MISO with additional power if needed. It is rare that MISO calls on New Ulm to supply additional energy, but when asked, this transformer needs to be in working order. The transformer allows New Ulm’s power plant to be in the MISO Market.

The engineering contract with PSE, Inc. is $112,500. The procurement and installation of the transformer will be part of a separate contract. The estimate for the full replacement of the transformer is $2.5 million.

The first phase of the project was budgeted in 2025 for $1 million, covering the engineer and the down payment on the transformer. An additional $1.5 million is budgeted in 2027 for the final transformation payment and installation.

The 1968 transformer at the Center Street substation is the oldest in New Ulm. The transformer was modified over the years to include oil coolers and a fans. The transformer is currently in working order, but due to old age Public Utility staff want to replace before there are problems.