Now add in the 50% efficiency of conversion of heat to electricity (and that's very optimistic), and it's only 1.5 megajoules, or 0.5%, right where I calculated

Now add in the 50% efficiency of conversion of heat to electricity (and that's very optimistic), and it's only 1.5 megajoules, or 0.5%, right where I calculated it based on initial information. IANAP, but I see no path forward to sufficient Q-total using plasma fusion to put this to any practical use. Unless the reaction can somehow be self-sustaining, I do not believe this will ever work.