Earlier quoted context omitted.
Is that supposed to be a problem? Large data centers are strong candidates for renewable energy conversions because they need backup power regardless. If the "backup power" is supplied by renewables then that becomes the primary generation source and the power grid becomes the backup. Doing it that way is sustainable and profitable.
Yes, but it doesn’t take long for people to start arguing that coal is clean and that diesel is green.
And if it isn't but you want them to use it anyway, that's easy too -- put a carbon tax on that coal fired grid power so that the solar is cheaper and they're back to doing what you want them to.
But don't expect them to choose to lose money while their competitors burn coal, undercut them and put them out of business because you decided that them doing that should be perfectly legal.