Earlier quoted context omitted.
If that is the original intent, why did that not get added into the law? Explicitly specififying that the exception only applies to emergency backup situations would have solved this, right?
My reasonable guess is that they did not want to make those case that need off-grid generation too hard to build. And never considered that anyone would build any actually significant amount of off-grid capacity. At certain threshold grid just makes economic sense. So rational actors would never do that. Sadly AI companies are entirely irrational actors so this really was rather hard to foresee...
For a genuine off-grid use case (eg: very rural locations), they could add a new exemption which allows installations up to X kW capacity per site where local grid connections do not exist. Set X large enough that it won't negatively impact applications like cabins or nature retreats, but small enough that it's not useful to a large operator like a datacentre.
Of course, this all requires a functional Congress... so good luck.