Jed the point is that there are more lies, and damn lies about hydrogen, than there is about having babies.

You are right about efficiencies adding up, they do, and if you added up all the claimed inefficiencies of hydrogen it would come to way more than 100% and that is obviously impossible, so you should be questioning at least some of them.

At worst we might see as little as 40% of hydrogen actually being put to use in an end user application.

But look, if the source energy is from sunlight, this is a triumph of creation, this is in a whole new ballpark from any improvments of efficiency that can be made in use of energy extracted from Earth.

Even at 99.9% efficient use of energy of Earth, there is still 0.01% destruction compared with the 40% creation, which is 40% efficient use of hydrogen from sunlight. See the difference?

On EROI, it is a very deceptive measure, it can be applied both honestly (Very rare!), and it can be applied deceptively (Normal!).

Normally, what is measured, is how much energy we put into a process, and this compared with how much we get out. But did anyone ask where the energy we put in came from, and what the cost of that was to the source it came from? Nope.

If it comes from the sun, then great, as said earlier we just used some energy that would have gone to heat if we did not use it.

Even if we are not using it efficiently, whatever we put to use of it is a triumph of creation, creating things other than heat.

But in the case that the energy came from Earth, the cost was millions of years of sunlight, if it was oil, for example. There is nothing we can take energy from on Earth, without it doing damage to Earth, converting a lot more energy to heat than we can get out of the extraction process. This makes a mockery of efficiency and EROI calculations, the heat generated adds to the heat generated by the energy of the sun, creating heat if neither we nor nature uses it. Notice we removed a lot of nature that used to use it.

This is the fundamental reason the temperature is relentlessly rising, we are contiuously destroying everything on the planet, converting it to heat. We never did create, our net effect is destruction, for everyhting we created, far more was destroyed. This is the penalty of taking all energy from the planet.

Worse, we do it wihout even realising, we do this deception of stealing energy from the planet without even thinking about it, because profit is the underlying mechanism, since money is energy, always, when money makes money then the energy gained in the extra money had to come from somewhere, and it wasn't the sun, because the sun gives what it gives for free, we can't steal more from it than it offers, we can only rip off the planet, and so it is ripped off, relentlessly.

CO2 is not a cause of anything it is a symptom, a multiplier of using mathematically negative energy.

Honestly dude, if you haven't got how this works by now, maybe you never will ;-)