Kaku's estimations are a bit off, there... Most technological breakthroughs, energy-wise, get more out of less. When we get into creating things like fusion reactors, the energy supply will be vast.
And it doesn't even seem to give a category for a civilisation which might have devised a method of vacuuming energy out of the 'ether' or some alternative dimension.
Look at the physical amount of material needed for the first atomic bomb, versus how much TNT an explosion of that size would have required!
If we restrict our understanding of extraterrestrial civilisations by how much resources they exhaust, we could easily be going about it in the wrong way... Doc Brown's time machine ran on household garbage, for crying out loud, whereas the former version required plutonium! A fictional example, sure, but in layman's terms, the principle's a feasible one. By the 'type 1/2/3' theory, the more efficient time machine would be regarded as less advanced.
For all we know, someone could be zipping around the galaxy on something powered by cotton wool...