Comment by tsjackson

There's plenty of space - deserts of the southwest for solar plus offshore wind could easily suffice to produce all of the power needed in the US by themselves. The issue is lack of grid transmission infrastructure, which is a reliability issue during times of extreme weather independent of whether it's a renewables based grid or not. As for materials, there are some rare earth metals that are used in some solar panels, but many others don't require them. If market conditions dictated, use of those materials would shift on it's own.