I. Introduction
Society's quest for sustainable energy moves us strongly towards carbon-neutral renewable sources such as wind and photovoltaics. Wind energy in particular, has shown strong growth and penetration, with several technologies showing sound economic fundamentals, even in the presence of minimal government subsidies. Significant levels of wind-penetration are being seen in Denmark and Germany, with similar high levels targeted in many countries over the next two decades. As the world moves towards higher level of penetration of wind resources on the grid, there is increasing pressure to locate the large wind farms offshore, where the issues of noise and the impact on the landscape are somewhat ameliorated. Several offshore wind farms have been recently completed, providing experience of the challenges faced and the solutions needed.