G. Antoniou et al. (Eds.): ESWC 2011, Part II, LNCS 6644, pp. 270–284, 2011. © Springer-Verlag Berlin Heidelberg 2011 An Approach for More Efficient Energy Consumption Based on Real-Time Situational Awareness Yongchun Xu, Nenad Stojanovic, Ljiljana Stojanovic, Darko Anicic, and Rudi Studer FZI Research Center for Information Technology 76131 Karlsruhe, Germany name.familyname@fzi.de Abstract. In this paper we present a novel approach for achieving energy efficiency in public buildings (especially sensor-enabled offices) based on the application of intelligent complex event processing and semantic technologies. In the nutshell of the approach is an efficient method for realizing the real-time situational awareness that helps in recognizing the situations where a more efficient energy consumption is possible and reaction on those opportunities promptly. Semantics allows a proper contextualization of the sensor data (i.e. its abstract interpretation), whereas complex event processing enables the efficient real-time processing of sensor data and its logic-based nature supports a declarative definition of the situations of interests. The approach has been implemented in the iCEP framework for intelligent Complex Event Reasoning. The results from a preliminary evaluation study are very promising: the approach enables a very precise real-time detection of the office occupancy situations that limit the operation of the lighting system based on the actual use of the space. Keywords: Energy Efficiency, Complex Event Processing, Semantic Technology, Office Occupancy Control. 1 Introduction Real-time processing has become very important for sensor-based applications, since the quantity of data being generated from sensors requires on–the-fly processing and immediate reaction in order to be effective. There are many examples, starting from item-tracking in RFID-supported logistics to remote patient monitoring in eHealth. Indeed, real-time awareness enables the detection of problems (e.g. a damaged item in a delivery, or an acute health problem in a patient) as soon as they happen, so that the reaction can be successfully performed. Note that the same mechanism can be used for preventive reactions, i.e. reacting before a problem would happen. In the nutshell of this mechanism is the ability to recognize in real-time 1 (or even ahead of time) some interesting situations, what is called “real-time situational awareness”. Note that this goes beyond the traditional (static) situational awareness 1 We consider “business real-time“ as the criteria for declaring something to be processed in real-time.