aillarra

Hydrogen, like electricity and batteries, is an energy vector: you spend more energy producing that form than what you get from it.

Fossil fuels in general (maybe not shale oil) are sources, since you get more energy than what you spend. So, their energy return on energy invested (EROEI) is positive.

In this regard, we're facing diminishing returns, the low hanging fruit is long gone. This, plus resource scarcity, is going to be a huge limiting factor to growth…

People in general is not aware there are physical limits with energy sources and materials. We won't grow forever, actually we'll probably shrink once we hit the limits.

It's going to be a shock for a lot of people, specially in techno-optimistic communities as HN.