(a)  In General.⁠—Not less frequently than annually, the Secretary of Defense shall submit to Congress a report that, for the year covered by the report⁠—

(1)  identifies each instance in which the Secretary purchased drop-in fuel that was not cost-competitive with traditional fuel; and

(2)  for each instance identified under paragraph (1), states whether the purchase was based on a military requirement or not.

(b)  Definitions.⁠—In this section:

(1)  The term “drop-in fuel” means a neat or blended liquid hydrocarbon fuel designed as a direct replacement for a traditional fuel with comparable performance characteristics and compatible with existing infrastructure and equipment.

(2)  The term “traditional fuel” means a liquid hydrocarbon fuel derived or refined from petroleum.