This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. Citation information: DOI 10.1109/TII.2014.2326411, IEEE Transactions on Industrial Informatics

Abstract—The intention of this paper is to provide an overview of using agent and service-oriented technologies in intelligent en-ergy systems. It focuses mainly on ongoing research and devel-opment activities related to Smart Grids. Key challenges as a re-sult of the massive deployment of distributed energy resources are discussed, such as aggregation, supply-demand balancing, electricity markets as well as fault handling and diagnostics. Concepts and technologies like multi-agent systems or service-oriented architectures are able to deal with future requirements supporting a flexible, intelligent and active power grid manage-ment. This work monitors major achievements in the field and provides a brief overview of large-scale Smart Grid projects us-ing agent and service-oriented principles. In addition, future trends in the digitalization of power grids are discussed covering the deployment of resource constrained devices and appropriate communication protocols. The employment of ontologies ensur-ing semantic interoperability as well as the improvement of secu-rity issues related to Smart Grids is also discussed. Index Terms—electrical grid, smart grid, distributed genera-tion, renewable energy sources, power balancing, multi-agent sys-tems, service-oriented architectures, active demand response. I