ok,
real world alternator ratings is what the alternator actually puts out in real life, i.e. bolted to a hot engine in a hot engine compartment at a relatively slow speed(idle). not what it puts out in some manufacturer test lab where they will do whatever it takes to inflate the numbers.
BTW this is true for solar panels too. you will never see what the panel is rated for.
using a V-8 engine and an automotive alternator as a generator is the most inefficient way to get power. but don't get me wrong it is good to have the alternator as part of the total recharge package.
so back to your question as to what do you need to do?
1. drive to where you don't need AC
2. use shore power
3. use a portable generator
4. have a big old honkin solar array and lots of batteries
my preferred method is number 1.
highdesertranger