NorthWestern Energy says it has been notified by the Bonneville Power Administration that BPA will not use a proposed $1 billion Mountain States Transmission Intertie to serve its southern Idaho loads.
BPA cited market uncertainties and environmental issues for its decision.
NorthWestern Energy said it may have to write off up to $24 million it has already spent on survey and investigating costs for the proposed 430-mile power line.
City of Idaho Falls spokesman Brad Huerta said the project was one of six options being considered by BPA to deliver power to Idaho Falls Power.
Huerta said BPA has instead decided to pursue the Gateway West project, designed to deliver Wyoming wind power to Idaho and other markets.