International cooperation can be a major source of new energy-efficiency knowledge and technology for developing countries. By participating in international research groups or taking advantage of foreign technical assistance and technology transfer in specialized energy-efficiency fields, countries have tapped state-of-the-art advances. Local partners can reap substantial benefits from international cooperation linked to local policy measures when there has been substantial preparatory activity, when technology is adapted to local conditions, when cooperation at the working level is sustained and when public-private partnerships are given high priority.