What about transmission losses? Is this massive solar farm one big one, or spread out in little chunks?
What about cloudy/rainy days?
What about the solar panels not on the equator/tropics? As you move farther away, the sun’s rays are less perpendicular, and hence less energy is reaching the surface. You won’t get your full 1000W/m^2 each day.
Overall, it will take much more solar in practice than it will in theory...
The transmission losses will be big. No one wants to see these ugly solar farms near the neighborhood. The will force them to be out in the boondocks where the distance to send the power to the cities will increase the resistance loss in the transmission line. I have heard that solar and wind are not practical.