This is what will end fossil fuel use. I can envision toaster size units powering homes for a hundred or maybe a thousand years or a phone booth sized one also powering a neighborhood that long and with advances in battery technology all the cars could also be charged. Might even make these to power cars (that fly?) using tech we can’t imagine today.
The cool thing is they are completely safe. If the fusion reaction doesn’t occur it just goes cold and stops working. No risk of blowing up or spreading radiation like current nuclear energy plants.
Figure with infrastructure install; most of the world could be fitted within 30-50 years. Kids today will see it but anyone over 50 probably won’t unless it gets developed and installed much faster. Still; it is something to cheer about.
Not with this technology, but by fusing anti-matter with matter. Much of the mass of an atom actually comes from the anti-matter inside, in a wild entanglement with the matter. Someone will eventually figure out a cheap way to throw in a monkey wrench.
You’ll still need coal & natural gas for long chain organic molecules for plastics, etc.