Postal Service Electric Motor Vehicle Act - Directs the Postmaster General to: (1) replace at least 10% of the gasoline-powered motor vehicles in the Postal fleet with electric motor vehicles manufactured in the United States during each year in the five-year period beginning on the enactment of this Act; (2) ensure that at least 75% of the Postal fleet is comprised of such electric motor vehicles by the end of such five-year period; (3) ensure that manufacturers of such electric motor vehicles solicit competitive bids for electric drive components and storage devices from domestic manufacturers that participate in the Department of Energy's Electric Drive Vehicle Battery and Component Manufacturing Initiative (or successor program); and (4) report on expenditures made, savings realized, and revenues received by the Postal Service by implementing this Act.