If we truly used up all solar and wind power on the planet (which is a mind-bogglingly large amount of energy) there is still nuclear fission which is also a very large amount. Then if we invent fusion, that's basically infinite energy for free. And on top of all that, Earth is not the only planet, and the Sun has energy that does not only hit the Earth, so we can be construct a Dyson sphere.
Energy from our human scale today is basically infinite when we count all the sources available to us.
Solar and wind were brought out up because if any other energy source (like fusion) was used, then waste heat would be generated that would eventually (at exponential growth scales) boil the planet. And we could only, even the best case scenarios, ever only use a fraction of the available wind and solar that exists. Biological life is also solar powered so there's only so much you can take before that's an issue.
Energy from our human scale today is basically infinite when we count all the sources available to us.