A little harsh and out of context.

He was applying the definition of sustainability as the Prussian's used it to our current energy production. Their time frame was 2 harvesting periods. Yours seems to be quite a bit longer.

Not too harsh and definitely not out of context.

If the author understands H2 energy and plug-in hybrids, he should not speak on subject which even most climate scientists do not understand. Doing so only casts shadow of doubt on his testimony.