Because NWE is an investor owned monopoly, and their investors make more profit by choosing the most expensive power options - not necessarily the ones that are best for Montanans.(link to cost plus)
Even though coal is now more expensive than wind or solar generation it has provided reliable baseload power to Montanans for generations. People at NWE and regulators are understandably cautious about switching to something new, especially since blackouts can be fatal. But we know now that burning coal kills tens of thousands of Americans every year and that fossil fuel use is driving climate change. Renewables are now cheaper than the fossil fuel technologies of the last century, are reliable, and can help protect our kids’ future. If NWE acts quickly, we will have affordable, reliable power and thousands of good Montana jobs.