I would be hugely surprised if we have a Mr. Fusion future where you toss garbage into it and get electricity. More likely is that you'd have to buy fuel pellets periodically. It's not free to package them into household-sized packages and ship them to every home.

Oh, god, I can even see the pain... just like inkjet cartridges. "Non-genuine fuel cartridge detected. Please remove and replace with a genuine cartridge."