A local company uses eBullit, but can only get about 4 hours out of the 500w battery due to hills.
I could see an advantage in offering a 1000w light-moped version however these would be illegal on cycle paths.
Unrelated, they do manual powered boats too: http://www.dpdhl.com/de/presse/pressemitteilungen/2017/start...
I work next to a depot of those so I occasionally share a bike path with them while they are in cruise mode (moving to their delivery area, as opposed to going mailbox-to-mailbox). They go a brisk pace considering the load, but certainly not much faster than the speed required for comfortable balancing. This is no bike messenger from hell tool designed to win alleycat races (though that wouldn't exactly be the home turf of 2x11 componentry either).
Between 250W of assist for hops and acceleration and a very narrow speed band to optimize the gearing ratio for, you really don't need a multispeed transmission.
http://www.go-swissdrive.com/en/the-go-swissdrive-system/mot...
Singlespeed, I assume you just got this from the drivetrain type which doesn't really relate to hub-geared electric motors.
I think the idea here is that the electric motor will help in those cases.
Just to clarify your statement about batteries, you seem to have mistaken the motor rating for battery rating. Motors are rated in watts, batteries are rated in amp hours.
Except for when I'm towing kids in a trailer. 70kg extra means that the motor will drop out when speed drops below 5-6 km/h, because it's a hub motor. 250W isn't quite enough in that situation. Am contemplating upgrading to a longtail now that the kids are older, and will definitely get a mid-drive if I do.
1: https://windsorsradweg.files.wordpress.com/2012/01/cropped-d...
Clearly they were not particularly fast vehicles and the range wasn't necessarily massive, but they did the job and were used for a variety of tasks (most operators expanded from diary to a range of different, fresh, produce).
What killed them off - they are extremely rare now - was the rise of supermarkets and out-of-town shopping. I guess, though, that supermarkets won not from convenience but choice, and that internet shopping retains the choice element but now convenience could win out.
Vehicle website: http://www.streetscooter.eu/