May 6, 2009 — The Montana Public Service Commission (MPSC) voted four to one this week in favor of NorthWestern Energy’s application for approval to construct the Mill Creek Generating Station (MCGS) near Anaconda, Mont. A final order on the request is expected by May 22.
After considerable discussion on the proposed construction costs of the 200 MW natural gas-fired combustion turbine plant, the MPSC commissioners also voted unanimously that the $81 million cost for the turbines was prudent. The commission will determine the prudency of the other MCGS costs at a later time. Among other actions, the commissioners approved the plant’s return on equity at 10.25 percent and debt at 6.5 percent with a 50/50 capital structure and accepted the plant’s carbon offset plan as filed.