Alternator versus plug-in 12v battery charging

[Crashy]

If the alternator is only 21% efficient, how can it be 4x grid cost? That implies 4 x 21 = 88% would be possible from a utility sized generator. That's obviously impossible. Generator power is really expensive.

I've read at least ten of these white papers, in addition I've extensively studied (and practiced for 4 years) off grid power, and I'm certain the real cost of a kwh is more like 10-20x grid cost.

If there was such a small difference between alternator kwh and grid then plug in hybrids would not be a thing....

[Crashy]

In order of highest losses to lowest:

Stator resistance
Diodes
Hysteresis
Regulator
Bearing friction
Fan
Eddy currents
Rotor resistance

[oil pan 4]

Why are the diodes and rectifier seperate?
Any other diode losses for diodes used in the voltage regulator circuit for example would be negligible.

Also eddy losses should very widely from old versus new alternator design. For the old designs thick iron laminates were used for the stators iron core just because they were cheap, in newer alternators very thin much more efficient laminates are used.

[Crashy]

Diode losses are enormous.
0.7v drop x 2 = 1.4v on 14v output, that's 10% bam!

Why are they separate? Because they are different components, they can be isolated and tested separately. Each can be replaced by a more efficient component such as schottky diodes and buck converter