Customs duty exemption for machinery used in non conventional energy instruments, conditional on specified government certification requirements. Exempts machinery in Chapter 84 or 85 imported for manufacture of instruments, appliances or equipment functioning with non conventional energy from customs duty in excess of the rate calculated at 25% ad valorem and from the whole of additional duty, conditioned on (i) a certificate from an Industrial Adviser or Additional Industrial Adviser that the machinery are not manufactured in India, and (ii) a certificate from a Deputy Secretary in the Ministry of Energy that the machinery are required for those purposes.