This process will NOT "create" energy.
See, this is my problem with you people who put all your faith and belief behind "science", it just leads to pessimistic attitudes. I mean sure, I know it's unlikely that this system would be the exception to conservation of energy or any other principle of physics, but there's always a possibility that maybe, just maybe, plasma garbage vaporizing is where physics breaks down. So, if you want, I'll let you live in your miserable world where you're always right and nothing exciting ever happens. All I ask is that you just don't disturb me in my world, a world of imagination and possibilities, a world where anything can happen, a world where flying cars, jetpacks and sophisticated sex robots are just around the corner and yes, a world where garbage vaporizes can run amok, producing more energy than is put into them thereby destroying the universe. Screw your science, that's the world I want to live in.