Well anyone truly interested in wind energy, which probably doesn’t include anyone here, has had many experiences of burning out generators. The reasons are twofold:
- When the wind gets strong, the turbine will exceed the power it was designed for. this can burn out a generator pretty fast.
- Sustained high winds can slowly cook a generator, until a “hot spot” begins to develop anywhere in the stator windings. Once the wires begin to heat up in any small area, the electrical resistance of the hot wires is increased, resulting in an unstoppable “runaway” heating episode that cooks the generator very quickly. Upon later dissection, one can see where the problem started, and how it spread.
Very few initial attempts at wind energy provide enough generator for the amount of power encountered in strong winds, especially sustained strong winds. Almost every new attempt at producing wind energy systems encounters this limitation. It usually means you need
a) a bigger generator with more copper
b) better overspeed protection for the turbine itself.
If you haven’t built and run a lot of wind turbines, you wouldn’t know about any of this, but it seems likely to me that projects like Makani, and maybe the kite-reelers, may have encountered generator overheating, and that may be one reason why they always inexplicably give up, and never have anything in regular production.
Overall, there are many potential failure points in wind energy, and probably all the more so for new types of systems. Of course, most drag-based turbines, like Savonius, will not be making too much power, and are unlikely to burn out any generators, since they are unlikely to ever produce more power than expected - almost always far less. But if you do have something that makes power, look out, because what was your biggest goal will quickly turn into your biggest problem! 