The remaining 4% are likely due to the higher and steadier winds at the higher altitude. And the cost savings are likely less about building materials which li

The remaining 4% are likely due to the higher and steadier winds at the higher altitude. And the cost savings are likely less about building materials which likely scale at more than quadratic pace with height, but about labour and maintenance. Each trip out to an offshore base is costly, fewer trips made both for building and for maintenance saves a lot of money.