Even if we can get fusion to work, it will never be economical. Just because the fuel (water) is free, that doesn't make the energy free. The fuel rods for fission power plants are already a rounding error in the cost of energy. It's the capital costs that dominate the equation, and fusion plants will be at least as expensive as fission, which is more expensive per KWh than solar.
https://thebulletin.org/2017/04/fusion-reactors-not-what-the...