The Board of Regents of the University of Nebraska is authorized to furnish and to enter into agreements with the Nebraska State Fair Board to furnish a supply of electric current to the Nebraska State Fairgrounds and buildings, which shall be furnished by the heating plant located upon the city campus of the University of Nebraska at Lincoln, except that such electric service shall be furnished only if the same may be generated and furnished without impairment or reduction of the power necessary to proper and efficient operation of the University of Nebraska and the State Capitol, including the executive mansion.