For wonks: The Problem with Wind Energy

Real Engineering (youtube.com)

Comments to this video: "Wind turbine service technician here, actually modern machines doesnt need to achieve 1500-1800 rpm to produce power, thanks to the converter system its possible to start producing usable power as low as around 900-1000 rpm (about 3.5 / 4 m/s of wind on 150m diameter machines at max blade pitch angle). The way its done is simply to lower the voltage frequency on the generator side of the converters (while keeping 50/60Hz on the grid side). The 1500-1800 range is now more of a "max power" range if the wind speed is high enough (4.2MW for a Vestas V150 MK3E for example, at about 11m/s). About the maintenance on gearboxes in fact there is not really much to do most of the time, as soon as the service is correctly done (filter changes, oil levels) they can last more than the 7 years you are speaking without any issues. Of course gearboxes problems are possible, but they are pretty rare compared to the quantity of machines."

"Thanks for the video, but it's a bit outdated. Wind turbines nowadays have better power control systems that allow the "inertia" effect and allow 50/60Hz output and variable speed without all of the power going through an inverter. The gearbox has a design life equivalent to the turbine's design life (15 years in France generally)."

"Recently started working for a bearing manufacturer. Among the biggest problems with the bearing replacement is the fact that it requires removing the blades, which requires the use of cranes, which are very expensive and have to be scheduled. Apparently some companies are switching to split-ring bearings, which can be replaced without removing the blades. It's my understanding that they wear a little faster, but they reduce the cost of each replacement so much that it's incredibly worth it. Just thought I'd throw in my two cents to show that there are entire industries working to solve this problem and that it's not unworkable."

More comments on this subject here.