Subject to sections 
8835 and 
8836 of this title, the Secretary of Energy may commit to guarantee, and guarantee, against loss on up to 90 per centum of the principal and interest, any loan which is made solely to provide funds for the construction of a municipal waste energy project and which does not exceed 90 per centum of the cost of the construction of the project involved, as estimated by the Secretary on the date of the guarantee or commitment to guarantee.