I immediately thought about the car stereo guys they run stronger alternators and power massive amount of subs and speakers. But I know nothing about big trucks and their electrical needs. They have refrigeration and other electrical needs I am unsure of.

You made me curious. Big refrigerators and shipping containers have their own diesel engine: https://en.m.wikipedia.org/wiki/Refrigerator_truck They are independent from big truck’s power system. That is a solution for powering electronics - external diesel generator.

10 kW is almost 10% of the max output of the engine in a honda civic. for another comparison, that would be like running three typical car AC systems at max simultaneously. so not infeasible, but a meaningful hit to fuel economy in a smaller vehicle. it would be even more detrimental to the range of a small EV.