Microlighters

How about this as an alternative to that Rattex?

http://www.electraflyer.com/trike.php

I beleive SoloWings are also experimenting with electric engines

I am an electrical engineer and the one thing that scares me, apart from the fact that electrical planes don't have much range (they are really motorised gliders), is the question of battery life. When the figures for battery cycles are quoted, these are really theoretical. Reality will be much shorter. I will trust them more when they are proven. So if you are in a plane with not much endurance and you are also not sure how much the batteries have degraded, you are taking extra risk and one difficult to quantify.
So the quantity TBO is now replaced by TBBR (Time Before Battery Replacement), and this offsets all the advantages, quietness, cleanness, reduced noise, low "fuel" cost.
If the battery hurdle can be overcome (after all Toyota can provide a 10 year guarantee on the Prius battery), and you can get a bit more range in an affordable battery pack, then this becomes a very attractive option.

See also yuneeccouk.site.securepod.com/. This is a Chinese company with a two seater plane, single seater microlight and a paramotor unit. I think it is also possible to buy a motor/prop/battery/controller arrangement to fit on your own trike (CAA?). The company seems very professional and quotes >500 cycles whilst monitoring each battery in a pack for both charging and discharging - the right way to do it.
They don't want to quote a price on their website now, but I saw $88k for the two seater plane previously (more than 1/2 mill here) - bit expensive.

The only thing that worries me too is the batteries. They basically use LIPO batteries the same as in model airplanes lately. Mismanagement of those can even cause them the burn or explode so the manufacturers will have to make very sure they have that aspect in hand.