Book excerpt: This book evaluates the potential of the combined use of district heating networks and cogeneration in the European Union (EU). It also proposes measures to remove barriers hindering their widespread implementation, formulates policies for their implementation, and evaluates their economic, energy, and environmental consequences. The book presents a preliminary assessment of the likely cost and the impact of widespread adoption of district heating networks and cogeneration carried out in three cities that represent the variety of climatic conditions in the EU. Based on this assessment, it is estimated that by undertaking the maximum economically feasible implementation across the EU, fuel savings of €95M/year would be achieved, representing energy savings of 6,400 petajoules (PJ), which is around 15% of the total final energy consumption in the EU in 2013 (46,214.5 PJ). Using simple and quick calculations and not specific software, the method used allows the evaluation of the potential benefits of retrofitting existing power plants into cogeneration plants and connecting them to nearby heating networks. In light of increasing energy costs and environmental concerns, the book is of interest to heating engineers, city planners, and policy-makers around the globe.