Montana-Dakota Utilities Co., a division of MDU Resources Group, Inc. announced Tuesday the company had signed a 25-year agreement with a subsidiary of Duluth- based ALLETE Clean Energy to purchase the power from a wind farm expansion near Hettinger, according to MDU's press release.
The expansion of Thunder Spirit Wind will boost the combined production at the wind farm to approximately 150-megawatts and will increase MDU's generation portfolio from approximately 20 percent renewables to 25 percent. The original 107.5-megawatt Thunder Spirit Wind project was constructed by ACE and included 43 turbines. The power purchase agreement for the original project was finalized in October 2013 and purchased by MDU in November 2014. The expansion will include 13 to 16 turbines, depending on the turbine size selected, and will be constructed by ACE.
Construction for the project is estimated to be $85 million and is expected to be completed by December 2018.
The agreement also includes an option for MDU to buy the project at the close of construction next year.
"Our relationship with ACE on the first phase of Thunder Spirit Wind proved to be a winning formula," said Nicole Kivisto, MDU president and CEO, in the press release. "We are in need of additional energy to meet our growing demands, and with the easements, interconnection to the grid and permits already in place from the first phase of Thunder Spirit Wind, it makes this a great project for Montana-Dakota."
Mark Hanson, MDU's senior public relations representative said the company would decide on purchasing the second-phase of the wind farm later this spring or summer. If the purchase option is pursued the company, it would file an advance determination of prudence with the ND Public Service Commission sometime in the summer.
This is the only power purchase agreement that MDU currently has with renewable energy in the state.