The general rule is: the bigger and the newer the offshore wind turbines, the larger the capacity factor becomes and hence the lower the per kWh price.
The champion: Dudgeon (last 12 months) ==> *** 65.3% ***
Dudgeon: 67 Siemens 6 MW turbines, 32 km offshore Norfolk, operational since October 2017, owners Statoil, Masdar, Statkraft, water depth 18-25 m, rotor axis 110 m, rotor diameter 154 m, nameplate capacity factor 48%
[ge.com] – Haliade-X Offshore Wind Turbine Platform
The Haliade-X 12 MW also features a 63% capacity factor*—five to seven points above industry standard. Each incremental point in capacity factor represents around $7 million in revenue for our customers over the life of a windfarm.