We're talking about two different things. You're talking about what IS happening. My comment was about what CAN happen, what's POSSIBLE by the laws of physics.
If 10 million windmills magically appeared tomorrow, that wouldn't provide for most of our energy needs, because most of the time, the wind isn't blowing at the right speed.
Similarly, there is a certain amount of water in the rivers. Those rivers start at a certain altitude. The weight of the water multiplied by the distance it falls is the potential energy. To capture the energy in the water, you have to build dams. To capture more energy, you build bigger dams, holding bigger reservoirs (more tons of water). In order to have enough energy to meet our needs, the reservoirs would need to cover 1/3rd of the United States. It simply isn't possible.
I'm not saying it's unlikely, or that it's not politically viable, I'm talking about what's physically possible. The physics is such that there are two/three sources that have enough energy. Nuclear can, mathematically, provide enough. Old fashioned fossil fuels DO provide the majority. Clean fossil (natural gas and clean coal) can, at least for awhile. Wind cannot. It doesn't matter how many windmills you have, because at the moment it's not windy out.