How would you stop companies from just erecting solar panels and operating off the grid? Certainly generating your own power starts to make sense at some scale

How would you stop companies from just erecting solar panels and operating off the grid? Certainly generating your own power starts to make sense at some scale of data center power usage. Build a data center in the desert next to a few square miles of solar panels - companies are already doing this even without an energy tax. That's honestly why solar will replace grid power very soon: it's near impossible to regulate because you can't cut off access to the sun. It's the difference between buying a fish at the market for dinner and buying a fishing pole. The more I think on this though, the more I realize that corporations are probably going to become wealthier and stronger than most countries' ability to regulate them. They already have too much influence in government.