In considering the grid connection of ocean wave energy devices, and in particular, the connection of large offshore arrays, there are a number of technical and economic challenges that need to addressed by wave energy device developers. As device developers approach pre-commercial operation, grid connection factors will become increasingly significant in both technical and financial terms. In this study, some generally applicable, non-device specific challenges are examined. The costing issues involved in procuring, building and maintaining a grid connection are reviewed. The technical impacts on device design and particularly on generator system selection are also examined in detail. A grid connection costing case study in the Irish context is performed as a practical indicator of these issues.