Energy costs and climate change challenges the water industry to improve their energy efficiency. The number of examples of energy measures in water production and treatment is growing rapidly. In this paper, best practices of energy efficiency from the European water industry are presented with the objective of learning from each other. The best practices are collected within the framework of the Global Water Research Coalition's attempt to devise a global compendium ‘Best practices in the energy efficient design and operation of water industry assets’. The case studies in the compendium show significant energy savings in all parts of the water cycle. Examples with potential include the improved operational set up of pumping design, on line aeration control, and energy-efficient bubble aerators and sludge belt thickeners. Next to optimising energy efficiency across the water cycle, there are also opportunities for energy generation. Promising practices include biogas production from sludge (co)digestion and hydraulic energy generation from micro-turbines.
Keywords: best practices, energy efficiency, Europe, (waste)water