Customs exemption for energy machinery: duty relief subject to MNRE certificate and importer undertaking on specified use. Exempts import of machinery and components for initial setting up or demonstration of fuel cell power systems and for balance of systems operating on bio-gas, bio-methane or by-product hydrogen from customs duty in excess of a specified ad valorem floor, subject to a certificate from a Deputy Secretary-rank officer in the Ministry of New and Renewable Energy confirming the items and an importer undertaking to use the items for the stated purposes; misuse attracts payment of the duty differential.