The trend towards larger wind turbines still continues, driven by Chinese OEMs, with Goldwind, Envision Energy, and Mingyang Smart Energy all having 20 MW turbines in their R&D process, while several others have 16 MW or 18 MW in theirs. With wind turbines, bigger is better. They’re more powerful, both for dollars invested and for space – and height, of course, with stronger winds higher up. There are two reasons why it’s not all positives, and why some are calling for a halt to the size increases. One is reliability. A larger turbine is more liable to break under its own power – one big part of why they are an R&D route and not just a size choice. The…