Thanks for your reply, malgudi.

But this issue can be confusing, because it is my understanding that EmPower also makes 110V AC systems.

I am guessing UA 777's old configuration probably uses the old 15V-75W EmPower system. But I don't know if the new 777 configuration still use the same EmPower system. Can anyone who has flown on the new configuration 777's enlighten us?