Wind seems like a great complement to existing hydro capacity. Wind is a clean and renewable energy source which can provide considerable amounts of power. The problem of course is what happens when the wind does not blow. It is also possible to generate more than you need sometimes even when you struggle to meet demand at other times. Wind is inconsistent. It is hard to map capacity to demand.

The environmental damage of hydro is putting it in place to begin with. Once the dams are built is is pretty clean. Hydro can provide consistent power at any time. The concern with hydro is that, as you use it, the reservoirs go down. If you use it continuously, the water levels can drop faster than they are being replenished eventually leading to a problem. So, the problem with hydro is that it offers only so much total power before more dams have to be built ( which creates significant environmental damage ). You cannot really have too much capacity with hydro as you just let the water flow if the reservoirs are full.

If you are generating lots of wind power, you need less hydro and the reservoirs fill up. They act like a battery. If the wind power drops, you can ramp up the hydro until the wind comes back.

Together, hydro and wind create an electrical power system with significant capacity, consistent availability, and the ability to service spikes in demand while remaining green and renewable. Add as much wind as you need to create overall capacity. Use the hydro to smoothly match power delivery with demand.