Visions of the Future from an Airplane Window

In the early 1980’s I was selling high efficicency sodium lighting. I could look out an airplane window and tell that there was a huge potential to increase the efficiency of outdoor lighting. It was easy to see where old fashioned blue-tinted mercury vapor lights were being used and where the newer high efficiency gold-tinted sodium lights were. Over the next 2 decades the gold became ubiquitous.

Now when I look out the airplane window I notice all of the flat roofs on industrial buildings and shopping malls. Over the next 2 decades I expect them to become covered with solar panels. Parking lots would be nice to cover because they would provide shade, but that will cost a little more. Then we could have more electric power in the cities without new transmission lines, pollution, or NIMBY siting wars.