Unlimited for our current needs or on a planetary scale, but nowhere near enough at the scale of a solar system of galaxy. I doubt it would be enough energy to for example open a wormhole or accelerate a spaceship to even 1/3 of light-speed. Not only is the amount important, but also the ability to sustain the output.

We’ll just be on the first rung of the Kardashev scale. Of 3. However, the jumps between the rungs are huge (logarithmic). Complete control of planet, star, galaxy.