Every major advance in human technology, in human standard of living, has come with increases in energy density. From wood to charcoal to coal to oil to natural gas to fission power, the arc of progress in energy has always been toward greater, not lower, energy density. That is until the green energy types came along with their insistence on low-density sources like solar and wind.

So, with nuclear fission reactors providing the highest energy density available today, the question arises, "Where do we go from here?" What energy source can provide greater energy density than fission power?

The answer is fusion power. But the problem is that it's a few decades away, and has been since the '50s: