Directive 2004/8/EC of the European Parliament and of the Council on the promotion of cogeneration based on a useful heat demand in the internal energy market.

The aim of this Directive is to increase energy efficiency and improve security of supply by creating a framework for promotion and development of high efficiency cogeneration of heat and power based on useful heat demand and primary energy savings. It lays down provisions applying to the cogeneration technologies listed in Annex I. Cogeneration is defined as the simultaneous generation in one process of thermal energy and electrical or mechanical energy.