If your looking for a way to sell hand made electric bicycles, you need an extraordinary design. This is one of the best ideas I have seen, even if it does use a hub-motor. At least it is a geared hub.
One of the main problems with hub motors, besides the lack of gears, is the lack of ventilation. This modification uses fans to cool the interior..
Most people just use a direct drive hub motor that uses much more energy than is needed to climb steep hills. Some make self contained hub motors and claim they are the next big thing; ending up with a wimpy machine that does nothing for real hill climbing with cargo.
Even the Elf car has a less than perfect power system; they use a hub-motor set at a 1:1 gear ratio with no ventilation; and no gear box! Even if it has a voltage multiplier circuit, it is a waste of energy!!! And no one knows enough about why gears were invented to say anything about it!
Read how this bike was built on the Endless-Sphere forum: