NorthWestern Energy, a regulated investor-owned utility serving 650,000 customers in Montana, Nebraska and South Dakota, proposes to build and operate a 500 kV electric transmission line from Townsend, Montana, to the Midpoint Substation near Shoshone, Idaho, by 2013.

This transmission line will meet requests for transmission service from customers, other utilities, new generators and power marketers. The project will relieve current constraints on the high-voltage transmission system, or electric power grid, in the western United States.

The MSTI project will enhance the capability of the power grid that supplies energy to millions of people and businesses in the western United States every day. It would not only meet the energy needs of consumers but would also accommodate the transmission requirements of new generation facilities such as clean coal and wind. MSTI is a direct response to the growing need for electricity in the western United States and the requirements of the National Energy Policy Act of 2005 that took significant steps to strengthen the nation’s electric power grid.

Within the National Energy Policy Act of 2005, Congress authorized mandatory reliability and interconnection standards and directed the Department of Energy (DOE) to conduct a nationwide study of electric transmission congestion on the high-voltage grid. This study, which was completed in August 2006, identified electrical congestion on the existing transmission path between southwestern Montana and Idaho.

In addition, many western states have passed Renewable Portfolio Standards that require utilities to use clean renewable energy to meet their energy needs. Subsequently, governors in the western states have called for the availability of 30,000 megawatts of clean, diversified energy from the Western Power Grid by 2015. NorthWestern Energy has contracted with Power Engineers for assistance in identifying a preferred route and alternatives, and preparing preliminary engineering information for the project.