Avoiding energy wastage is a key element to stay competitive for manufacturing companies in the future. This paper presents an energy wastage identification and prevention approach for manufacturing environments. The approach describes the occurring types of energy wastage within manufacturing and specific indicators to identify each of them. Including additional external information, the significance of an identified on-going wastage can be determined and based on the type of wastage and the significance, concrete recommendations for measures to prevent the wastage are delivered. The approach provides a basis for a detailed energy efficiency concept adaptable to a specific company. The information processing procedures described in this approach are designed to be implemented with complex event processing technology enabling real-time information processing and quick reactions to prevent energy wastage.