The scale of flashlight batteries is a bit different from that of automobiles. The two can hardly be compared.
Why. There are electric cars on the market filled to the gills with very large "flashlight" batteries. It seems my point went way over your head. What I was attempting to tell you is that in viewing the economics of various "energy sources", the application for which it is being applied is the critical factor. There is not a hard and fast energy-in vs energy-out rule of thumb when determining economics as this article, and you seemed to imply. A solar powered swimming pool heater can make sense and a lot of people buy them, but a solar powered snow blower does not have a market.
The application drives the economics which drives the market.