Sure, Deuterium-Tritium fusion is really is impressive. But what if we look for something even more powerful? Something that is much more cleaner, i.e. doesn't release a b*ttload of neutrons during fusion?
Behold, I present to you, Aneutronic Fusion (Hydrogen Fusion).
In simple layman's terms, ordinary hydrogen has just 1 proton in its nucleus and 0 neutrons. This makes it the lightest element in the universe. This element is also extremely abundant. The Milky way is composed of more than 70% hydrogen, for reference.
Pound for pound, fusing hydrogen releases nearly 50% more energy than fusing Deuterium and Tritium atoms together, and 10% more energy than simply fusing only Deuterium. This proves to be an advantage.
You can find hydrogen anywhere. Stars, nebulas, gas giants, you name it. Heck yes, you can just get it free from the oceans. Just dissolve some lye or a strong base in water, pass some electricity through it.... BOOM! There you have it, simple hydrogen.
Deuterium on the other hand constitutes only 0.015% percent of the Earth's crust. This isn't a problem, as this is sufficient enough for us. But tritium.... well, it is, two words, EXTREMELY RARE.
At any given moment, there is just 15 pounds of tritium naturally occuring on Earth. This is because tritium is radioactive, with a half life of 12 years. Tritium is also extremely hard to synthesize, requiring a ton of complex fancy apparatus and bombarding Lithium with neutrons and stuff. In other words, it is a PITA to synthesize tritium.
Fusing 1 kg of hydrogen (Protium), releases nearly 640 TJ of energy, 2% of which is lost due to neutrinos, but the loss is so insignificant that it is easy to ignore it. 640 TJ of energy is basically enough to boil 2 billion liters of water. Using a conventional steam turbine, you can convert this heat energy into hundreds of terawatts of electricity, something that your hero will be very pleased with.
However, there are multiple drawbacks to this:
Protium/hydrogen fusion requires temperatures and pressures that are beyond what we can generate in a lab. You need hundreds of billions of atmospheres of pressure and millions of kelvins (The temperature part is easy, the pressure part is really hard) to create conditions suitable for fusing protium to generate energy, which is a reason why most fusion reactors favor D-T fusion over P-P fusion reactions. But this can easily be ignored, considering that this is your story and you can simply handwave the issues away.
Making a fusion reactor requires vast amounts of money, but that can be ignored, assuming that your hero is some trillionaire guy to whom money isn't a money.
Overall, hydrogen fusion reactors should be something that your hero should consider building to generate not just 1 TW but a power plant that generates hundreds of terawatts of electricity, and also, completely neutron-free.