There's been pretty much one major factor that made wind turbines more efficient: They got bigger. And it doesn't look like this trend is going to stop any time

There's been pretty much one major factor that made wind turbines more efficient: They got bigger. And it doesn't look like this trend is going to stop any time soon. Nobody wants your tiny wind turbine blades from 20 years ago, because when you put up new wind turbines you want the big, new, more efficient ones.