Associated Press: Four Western utilities are studying potential upgrades to a 500-kilovolt system in Montana to transmit wind power to the Pacific Northwest. NorthWestern Energy, based in Sioux Falls, S.D., announced Tuesday that it will work with Puget Sound Energy, PacifiCorp and Portland General Electric in Washington and Oregon to identify and evaluate one or more potential system upgrades to accommodate the transmission of wind and other renewable power. The study will focus on the Colstrip …