The integration of large amounts of renewable power, the will to create a single European Energy Market, and the requirements for system adequacy and security of supply are strong drivers towards more electricity interconnection infrastructure in Europe. This is especially true for the European seas with the North Sea in particular. During the last years, various proposals for an offshore grid in Europe have been published in the public domain, varying from research proposals to long-term visions or more concrete projects. Taken up by policymakers and other stakeholders, they have resulted in a number of ongoing initiatives like the Adamowitsch Working Group, the ENTSO-E Regional North Sea Group and the North Seas Countries' Offshore Grid Initiative. The paper provides the background on offshore grids and an extensive overview of the various proposals. Furthermore, the remaining challenges are discussed and explained in the context of the different initiatives. (C) 2012 Elsevier Ltd. All rights reserved.