You seem to be a fount of knowledge, Dutch. Every time I take off out of my home port in Australia for my 'overnight horror' flights north, there is a line of red blinking lights on the horizon delineating a row of huge wind powered turbines.
These things are monsters. Apart from their visual abomination on the landscape, danger to birds (and even aircraft), noise to local residents etc, they obviously require a huge amount of steel, concrete and other metals to construct; and of course, transport to site, energy involved in erection, and ongoing maintenance.
My question: how long does it take for these things to repay the 'energy debt' involved in the processing of their construction materials from raw products, their installation, and their ongoing maintenance?