If you basically ignore that they are all built in China. I'd say that's the most centralized mainstream technology to generate electricity by far, it's all down to a single country. We could even say it's down to a single person even, the power being so vertical in China.
> easy to scale.
Well if you don't care about how you are going to pass the winter maybe.
+ it is decentralized, cheap, low tech, low waste, easy to scale.