Wind power and solar are generally considered clean and environmentally friendly. Although the manufacture of their components, the generators, blades, solar cells, concrete foundations, and other parts generates many pollutants and releases a lot of CO2, the actual systems produce no CO2 when they are producing power. That makes them desirable from the viewpoint of climate change advocates.
The problem with these systems is that there are essentially no good storage mechanisms for the power they produce. All the power produced is "use it or lose it". Furthermore, the power produced is unpredictable, depending as it does on the vagaries of wind and cloud, and the lack of sunlight during night.