Section 57A. Any city or town having a municipal light plant may appropriate money for the maintenance and operation of such plant, specifying that the same shall be taken from the receipts of the department; and where such appropriations are made, the city or town treasurer may, in advance of the collection of said receipts, pay bills on account of the said appropriations, and any sum so advanced shall be repaid to the city or town from such receipts, when collected, and shall be applied as reimbursement to the city or town, or to the payment of any temporary loan made by the city or town in anticipation of revenue of that year.