7 U.S.C. § 940g

(a) Definition of renewable energy source In this section, the term “renewable energy source” means an energy conversion system fueled from a solar, wind, hydropower, biomass, or geothermal source of energy. (b) Loans In addition to any other funds or authorities otherwise made available under this chapter, the Secretary may make electric loans under this subchapter for electric generation from renewable energy resources for resale to rural and nonrural residents. (c) Rate The rate of a loan under this section shall be equal to the average tax-exempt municipal bond rate of similar maturities.