Caution: This math may be wrong.
In episode 6 of Neon Genesis Evangelion, NERV borrows a positron cannon from a government research lab to deal with the latest threat. This cannon takes all of Japan’s power output, for 37 seconds, to charge the rifle for one shot. According to the CIA World Factbook, Japan produced 1.017 trillion kWh for the whole year in 2003.
1.017 trillion kWh per year/365 days/24 hours = 116 million kWh per hour
So, Japan produces 116 million kWh per hour. However, Makoto Hyuga states that it will take atleast 180 million watts to pierce the AT field of the angel Ramiel. Seeing as it takes 37 seconds to charge the rifle*…
180 million kW per 37 seconds * (3600 seconds / 37 seconds) = 17460 million kWh per hour
So, if my calculations are correct, the rifle would need 17460 million kWh to charge for an hour; unfortunately, this is quite a lot higher than the 116 million kWh per hour Japan produces, infact, it is 150 times more. So, if Evangelion’s Japan in the year 2015 is to be able to power the rifle, it needs to produce 150 times more power than 2003 Japan does.
* Counting from the ejection of the first shot’s fuse, to the pulling of the trigger for the second shot.