This is also about 60,000 square miles. About 78 trillion dollars. As daunting as the expense is the fact that this amount of PV is hundreds of thousands times the Current annual output of the PV industry. Let's think of some other ways to put the problem into perspective. The first is that sunlight arrives in diffuse form.
People also happen to exist in diffuse form across the land.
Dividing the area of panels by the 270,000,000 people in the US, we come up with 574 square meters per person, an area approximately 24 meters on a side. While this is certainly high, it is not so high that the idea should be dismissed entirely. In inflation adjusted dollars, a decline of a factor of over 100. Cost of the technology continues to decline. It is quite reasonable to expect that, especially if PV enters extremely large-scale production, cost will drop dramatically.