(1) “Electric utility facility” means a facility which a municipality is authorized to acquire as part of a municipal electric utility system under this act or other law.

  (2) “Governing body” means the council, commission, or board of trustees of a municipality, or when the charter of a municipality provides that a separate board has general management over the municipal electric utility system, “governing body” means that separate board, subject to review by the legislative body of the municipality as its charter may provide.

  (3) “Governmental unit” means a municipality or a joint agency.

  (4) “Joint agency” means a public body corporate and politic consisting of a combination of 2 or more municipalities, authorities, or other public bodies organized under article 3.