Not sure where the math came from in the OP but...
100W * 0.33 * 0.50 * 0.95 * 0.50 = 7.8
This clearly is lower that 16W
Might have to look more clearly at the article and see where the discrepancy arises.
Also the OP forgets that the quoted 67% includes electrical generation. ie the turbine.
And a typical phone charger (a Switch Mode PSU) will have an efficiency > 75%. So our calculation becomes:
100W * 0.33 * 0.95 * 0.75 = 23.5