google and wolfram alpha tells me one fully tanked 737 stores 16 tons of kerosene, which translates to 261.1 GJ at 35% efficiency (72.5 MWh). doesn't sound too far off. assuming the same energy will be required for an electric airliner and you want to charge it to full in an hour... you probably need much more than 72.5MW power plant per aircraft because fast charging is nonlinear...? numbers which are hard to comprehend at scale in any case