Here are the average capacity factors of every Danish offshore wind farm, newly updated to include data to the end of September 2014. The Anholt 1 windfarm, which only opened in 2013, hit an average capacity factor of 51.1% for the last 12 months. Thanks to the wonderful statisticians and data managers at ENS and Energinet.DK, we have a large amount of detailed data from Danish onshore and offshore wind farms.
Danish windfarms also include the most productive wind turbines in the world, at Rønland I: the turbines have been operating for over 11 years now, with a lifetime capacity factor of 44.2%; of its eight turbines, four are rated at 2.3MW peak power, and each of those four had by the end of July 2014 generated over 100 GWh: the first turbines to pass that milestone.
The capacity figures are calculated by calculating, for each turbine in a given wind farm, the number of hours since it was first connected to the grid. This is then multiplied by its capacity, to give the number of peak-MW-hours. These figures are summed across all turbines in a wind farm, and divided into the total energy generated by that wind farm, to give its capacity factor.