This talk will describe the potential advantages as well as the many difficulties which must be overcome if we are to make future generation solar cells using nanoscale materials. Nanoscale PVs have the possibility of being manufactured on an enormous scale. They also offer the possibility of harnessing new physics which arises in dimensionally controlled systems to control energy dissipation. Yet, nanoscale systems have high surface areas with many potential trap sites and present difficulties for how to spatially organize electrical transport pathways. These issues will be illustrated with recent experiments utilizing colloidal inorganic semiconductor nanocrystals.