Minn. Stat. § 216B.40: EXCLUSIVE SERVICE RIGHT; SERVICE EXTENSION.

Except as provided in sections 216B.42, 216B.421, and 216B.422, each electric utility shall have the exclusive right to provide electric service at retail to each and every present and future customer in its assigned service area and no electric utility shall render or extend electric service at retail within the assigned service area of another electric utility unless the electric utility consents thereto in writing; provided that any electric utility may extend its facilities through the assigned service area of another electric utility if the extension is necessary to facilitate the electric utility connecting its facilities or customers within its own assigned service area.