Buy or build NorthWestern wants new power plant

NorthWestern Energy says its best option for supplying power to its customers over the next 20 years is to buy or build another natural gas-fired power plant so it can rely less on contracts with PPL Montana.

NorthWestern filed its biennial electric supply plan with the s tate Publ ic Service Commission last week. The plan continues the company's efforts to rebuild itself as a utility that owns power generation, rather than a company that distributes electricity purchased from others at market prices.

NorthWestern's plan also calls for adding 50 to 75 megawat ts of wind power and increasing...