Giving a velomobile electric support

[SlowCo]

Why not a hub motor used as a mid drive in the Velomobile itself like Warekiwi showed you? Why all the trouble of a push trailer that you always have to use if you want electric support? And then even a double wheeler that would need two hub motors and two controllers with a way to connect to your handle bar inside the Velomobile to be able to control it.
Just make a mid drive to support your pedals of the Velomobile.

 

[Warekiwi]

I've now been using the system I described earlier for over a year and 7000+ km. It's proven to be highly reliable and almost imperceptible regarding noise. Although capable of much higher speed/power I normally restrict it (via the Cycle Analyst) to the legal settings of 260W and max assist speed of 25kph (about 16 mph) This doesn't of course restrict the ultimate speed of the velomobile which easily reaches speeds close to 100kph (60mph) on downhills thanks to aerodynamics. I can pedal to about 70kph which corresponds to a cadence of about 130rpm in the highest available gear. Around the hilly local roads I tend to average about 4Wh/km (assistance) and with the 21Ah/48V battery this gives me an assisted range of over 200km.
The French guy who designed and installed my system used a powered trailer for a while (same motor and control setup) but has now reverted to a nose mounted layout like mine.
You can see a typical profile of a ride using my e-assisted QuattroVelo here--
https://ridewithgps.com/trips/40030444