Montana-Dakota Utilities Co., a division of MDU Resources Group, announced it signed a 25-year agreement with a unit of Allete Clean Energy to purchase the power from a wind farm expansion in southwest North Dakota.
The agreement also includes an option for Montana-Dakota to buy the project at the close of construction.
The expansion of Thunder Spirit Wind, located near Hettinger, ND, will boost the combined production at the wind farm to about 150 MW of renewable energy and will increase Montana-Dakota's generation portfolio from about 20 percent renewables to 25 percent.
The original 107.5 MW Thunder Spirit Wind project was constructed by ACE and included 43 wind turbines; it was purchased by Montana-Dakota in December 2015. The expansion includes 13 to 16 turbines, depending on the turbine size selected, and will be constructed by ACE. It is expected to be online in December 2018.
"Our relationship with ACE on the first phase of Thunder Spirit Wind proved to be a winning formula. 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," said company President and CEO Nicole Kivisto.
If Montana-Dakota buys the project, the capital will be incremental to the Nov. 22 announcement by MDU Resources regarding the utility group's capital expenditure forecast of $1.24 billion for 2017 through 2021. Construction costs for the project are estimated to be $85 million.