The German province of North Rhine-Westphalia, which has a population of 17 million, promotes energy efficiency in sewage treatment plants by providing financial support for energy analyses. Thanks to this programme, more than 200 sewage treatment plants have now been analysed and have subsequently implemented energy optimisation measures. To support these activities, the North Rhine-Westphalia Ministry for the Environment, Spatial Planning and Agriculture published a handbook entitled "Energie in Kläranlagen" (Energy in Sewage Treatment Plants), which is largely based on a publication of the same name released by the Swiss Federal Office of Energy. Specialists from "SwissEnergy for infrastructure plants" played a major role in preparing the handbook, as well as in developing the above programme in their capacity as project managers.