(a) On approval by the state energy conservation office, a state agency that reduces its energy or water expenses may use any funds saved by the agency from appropriated utility funds for the purchase of an energy-saving or water-saving device or measure. For purposes of this section, "energy-saving or water-saving device or measure" means a device or measure that directly reduces:
(1) energy or water costs; or
(2) the energy or water consumption of equipment, including a lighting, heating, ventilation, air-conditioning system, or other water-using system, without materially altering the quality of the equipment.
(b) A state agency, in accordance with the recommendations of an energy or water audit, may purchase energy-saving and water-saving devices or measures from appropriated utility funds if the savings in utility funds projected by the audit will offset the purchase. The agency shall retain in its files a copy of the recommendation and repayment schedule as evidence of the projected savings.