I don’t think you have any idea how much the power consumption is unfortunately. The roof would cover maybe 1-10% of the power consumption of a modern data center. A single rack’s power consumption is basically the same as a neighborhood. An entire data center is more like a small country.
To be clear I’m not trying to say it’s OK they’re using gas plants, I’m just saying why the solar power Musk promised was never going to be feasible.
Edit: My bad, this is a fab, I thought it was yet another XAI datacenter. Might be more feasible, but still - for energy intensive purposes, which this is likely to be, on-site solar can offset part of the energy requirement, but generally not all of it.