The future of power grids is expected to involve an increasing level of intelligence and integration of new information and communication technologies in every aspect of the electricity system, from demand-side devices to wide-scale distributed generation to a variety of energy markets. This paper provides a general outlook of the definition of this future in the US and the European Union and compares two approaches-GridWise (TM) and SmartGrid. It describes the contexts in both the worlds, as they influence the two visions of the future intelligent power grid, and as they form foundations at each respective federal level for supporting research in this field. The similarities and complementarities of the two research programs are examined. Within the framework of a solid precedence for trans-Atlantic co-operation in energy research, the time would seem optimal to set in motion active collaboration and educational exchange on GridWise and SmartGrid research. This paper will help energy policy makers to better understand the key issues determining the two different approaches and the two different policies derived from them; as well as a comparison of the solution provided in each case. This work will also be useful for researchers and industry decision makers to be aware of trans-Atlantic approaches, opportunities, and resources looking toward future, more intelligent and interconnected power grids. (c) 2006 Elsevier Ltd. All rights reserved.