Yancey, standby has its own power
afaik. There is also battery power and an inverter in the event both generators, apu and emergency generator fail.
But as you start to loose power sources, loads get removed to maximize what's left to the things essential for the pilot to try and save the aircraft... That's why pilots windshield heat, even though your talking a lot of power, is one of the last things to go. Hard to land an airplane by hand if you can't see out the front. Or that's what the pilots tell me, anyways.
