The expansion project is being developed at an estimated cost of $230m.
PPL Montana will increase the amount of clean, renewable power to 70% with a single 62MW unit in the new power house.
Smaller units which generates a combined capacity of 35MW are being replaced by the single units that can produce enough electricity to about 45,000 households in Montana.
PPL Montana vice president and COO Pete Simonich said our next project would be the completion of powerhouse, which is expected later this year.
The entire project is expected to be completed in 2012.
