The structure of the final energy consumption broken down by energy source and sectors is shown in Fig. 1. ‘‘Space heating, cooling and water heating’’ comprises low-temperature heat generation and air conditioning in buildings. ‘‘Steam production’’ includes industrial and commercial heat generation and process heat and ‘‘industrial ovens’’ include industrial and commercial facilities, reaching from small bakery ovens to large blast furnaces. The fraction ‘‘stationary engines’’ includes the final energy consumption of all kinds of engines which are not used for mobility, reaching from small engines in household appliances to large engines in industrial production processes. ‘‘Transport’’ comprises road transport as well as rail, air and marine traffic. Further categories are ‘‘lighting and computing’’ and ‘‘electrochemical purposes’’.