The authority shall administer a Clean Energy Upgrade Program to reduce overall costs to the property owners of a loan provided by an applicant to finance the installation of distributed generation renewable energy sources, electric vehicle charging infrastructure, or energy or water efficiency improvements that are permanently fixed to real property by providing a reserve or other financial assistance at a level to be determined by the State Energy Resources Conservation and Development Commission and the authority. Improvements financed pursuant to this program shall be for a residential project of three units or fewer or a commercial project that costs less than twenty-five thousand dollars ($25,000) in total.