And if there is no wind or sun for an extended period of time, I guess we just shut down our factories then?

The fact that the Greens have been flexible in some elements of their politics doesn't mean they are committed to a realpolitik approach when it comes to energy generation. They absolutely are not. In fact their record when it comes to science is really spotty, as they also oppose transgenics and even animal experimentation to a certain degree. They are clouded by preconceptions that are dangerous to us all.