Thanks for response. It is said by some that rooftop solar is 3x less efficient than commercial solar (I suppose since it is filtered through our utilities, less than optimal tilt angles, etc) but that so much area is available (while photovoltaics are getting cheap) is a big factor. If utilities "pinch" buyback rates and homeowners buy battery backups, even more efficiencies. Rooftop solar also would seem to have less environmental impact (not compete w farming and/or wildlife etc). If photovoltaic arrays are successfully floated in space, the "utility corruption factor" may still be in play. Surely subjects that someone on Medium needs to explore further.