Montana utility regulators say NorthWestern Energy would have to pay about $20 per megawatt hour for electricity from a proposed 80-megawatt solar power project near Billings.
MTSun LLC had initially proposed a rate of nearly $64 and in late November rejected NorthWestern's offer of about $43.50. NorthWestern is required to buy power from such renewable facilities at a rate that it would otherwise cost the utility to generate the energy. If they can't agree on a rate, the Public Service Commission sets it.
The PSC authorized the 10-year contract on Thursday a week after voting to cap contracts at 10 years. Previous contracts could run up to 25 years.
The Montana Consumer Counsel testified the longer contracts locked in potentially unfair rates which are passed on to NorthWestern's customers.
Officials with MTSun did not immediately return a phone call seeking comment.