The annual global energy consumption of humankind is 5 x 1020 Joules; roughly equivalent to the amount of sunshine that reaches our planet in one hour.
Covering 1% of Continental U.S. with 20% efficient PV systems would provide all energy needs of the US. Covering 0.2% of the surface would generate all the electricity that the US consumes.
To put this number in perspective: roads cover 1.5% of the U.S Asphalt as a solar collecting device;
This Dutch company has a working system . This concept is discussed here and Wpi is doing work on this.
Solar Concentrators turn larger areas to collect solar ie a window and deliver in smaller packages like the edges. Increasing the power aggregation potential 4 Fold. Mit Research here.
fuel cell powered by solar