Open-Source Scientific Progress.

Granted they have been working on the Joint European Torus (JET) in Oxfordshire for decades;
granted that the Torus uses magnetic containment to keep the fusion plasma away from the vacuum chamber walls.

The JET can now produce enough energy for a small town but only for a few seconds.
80% of the fusion energy is expelled as Neutrons, at a velocity that the magnetic bottle cannot contain, which means that the vacuum chamber walls must be replaced every five years.

This is a problem.

Now.

Where else is there a vacuum chamber? With walls a hundred miles thick that never wear out?

Space.

Put a magnetic bottle in space.
Harvest hydrogen from the near vacuum outside the bottle. Or send it from Earth, or the Moon, or Titan.

The energy would be virtually unlimited.
Getting it down would be a problem, except that we already have an established method for getting fusion energy to Earth-it is called daytime.

However, artificial solar energy would cause the planet to warm up.
So another means is required; beaming down energy by microwave is something I would consider risky.

What about non-visible laser?
Atmosphere.

Tethers?
That might work.

So, the biggest problem is the creation of orbital tethers to transmit the power down; granted that many people see the solution as mining Helium3-rich minerals on the Moon(less Neutron emissions) it might still represent an advantage to place the fusion reactors in orbit, to reduce the expense caused by bringing the stuff all the way down to Earth and getting it to power-stations.