Have jet engines always been able to generate the necessary electricity to supply today's widespread in-seat power ports, or has this perhaps been a function of greater engine efficiencies?
The power that a jet engine can produce has always been far, far greater than the electrical demand placed upon a passenger aircraft.Take, as an example, the 777. The 777 has two General Electric GE90 engines, each capable of 110,000 pounds of thrust at 145,000 horsepower. The onboard electrical generators have an output of 120 kVA (which is more than sufficient to power all onboard electrical equipment).Let's compare. 120 kVA is 0.12 megawatts, or 160.9 horsepower. The GE90 is, as previously mentioned, 145,000 horsepower, and the 777 has two of them, for a grand total of 290,000 horsepower (or 216 megawatts).So, 0.06% of the power generated by the 777's jet engines go to powering the electrical systems (plus whatever amount is lost in the conversion from brake horsepower to electrical power).