To every upvoted point, there has to be a counterpoint.
Sure jet fuel has a higher energy density, but that isn't the end all to the problem. You also have energy efficiency, which to my knowledge is pretty terrible on jet or turbo prop engines. I've been flying LiPo/Brushless RC aircraft for a while now, and in the right conditions your power efficiency comes right on par there with gas (minus any of the issues with ICE engines) In even better conditions, an electric plane can "recharge" batteries on descent.
There's a brand of starter electric planes called "Parkzone" One model (F-27 Stryker Brushed) was a particular favorite of mine. I went to a Gforce Lan event at Fort Mason, and on a lull between matches I flew it out in the heavy winds of the big green lawn. I kept that thing up there for 3 hours on a NiCd battery (usually only went for 15 minutes) I just sort of hovered it, more like "sailed" it and the motor just kept recharging the battery.
You can't really put jet fuel back in the tank like that. All sorts of crazy tricks you can do with electric though.