Energy efficiency is a foundation of any good energy policy; the economic, security and environmental benefits of energy efficiency have been recognised for decades. This paper explores energy efficiency policy insights derived from survey work in developing countries in 119 projects across nine manufacturing sub-sectors: automative/autoparts, cement/ceramics, chemicals, equipment manufacturing, food and beverages, metal, paper, textile, and other sub-sectors. The paper utilises financial return calculations to highlight gaps and opportunities for meeting the potential of energy efficiency projects in the manufacturing sector. It finds a generally high level of internal rates of return at a project level, but notes that these metrics do not always appropriately influence corporate decision-making.