Customs exemption for non-conventional power project imports limits payable duty subject to certification and long-term supply agreements. Exemption applies to imported machinery, components and auxiliary equipment for initial set up of projects generating power or compressed bio gas from specified non conventional materials, exempting duty in excess of a prescribed ad valorem rate. Conditions require a certificate from a designated Ministry officer, proof of a valid long term power purchase or municipal processing agreement where applicable, and an undertaking to use the goods for the specified purpose, with repayment liability for any unproved non use. The notification is time limited and has been amended by later notifications.