§ 13-f. Moneys for maintaining the municipal electric utilities association of the state of New York and any of its activities. The common council of any city or the board in control of any electric utility owned and operated by the city is hereby authorized to appropriate and expend annually from moneys derived from the operation of the said utility a sum to meet its proportionate share of the actual and necessary expenses of maintaining and continuing the municipal electric utilities association of the state of New York and any of its activities, in this state, for the purpose of devising practical ways and means for obtaining greater economy and efficiency in the operation of the utility.