Upon adoption of an ordinance or resolution by an affirmative vote of a majority of the members of the governing body at any regular or special meeting of the governing body called for this purpose, a municipality may pledge utility cost savings, conservation-related cost savings or any or all revenues not otherwise pledged or obligated from gross receipts taxes received by the municipality pursuant to Section 7- 1-6.4 NMSA 1978 and Section 7-1-6.12 N.M. Stat. Ann. for payments pursuant to a guaranteed utility savings contract with a qualified provider and any installment payment contract or lease-purchase agreement pursuant to that guaranteed utility savings contract. The ordinance or resolution shall declare the necessity for the guaranteed utility savings contract and related contracts or agreements and shall designate the source of the pledged revenues. Any revenues pledged for such contract payments shall be deposited in a special fund, and the municipality shall not use any other revenues to make such payments. At the end of each fiscal year, any money remaining in the special fund after payment obligations are met may be transferred to any other fund of the municipality.