[thrownthatway]

You can’t.

I’m willing to give it a go.

I’ve got the excess solar from the rooftop solar panels, the electrical and electronic knowledge, and the gas fitter and metal fabrication experience.

I have an oil free air compressor, and anyone can by a helium based cryo-cooler. I have an account with an industrial gas supplier.

Just enough knowledge to be dangerous.

If Nile Red hasn’t blown his lab up by the time I publish this comment, I reckon I stand a chance.

[KennyBlanken]

Round trip efficiency of hydrogen is at best 50% and at worse half that. You have the horrendous efficiency of electrolysis and then the equally bad efficiency in the fuel cell.

Efficiency pumping your excess solar into the EV itself is more like 80-85%, most of which is loss in the electronics, not the battery - those typically have a coulombic efficiency of over 95%.

Hydrogen a boondoggle. It's not nearly as stupid as making ethanol from corn (which is an energy-negative process) but it's close.

Also, "gas fitter and metal fabrication" experience isn't worth anything unless it was hydrogen-specific. It is far leakier than natural gas/propane. One of the biggest hassles of a hydrogen fuel chain is that the stuff leaks through everything.

[Ray20]

> Round trip efficiency of hydrogen is at best 50%

In fact, even this level of efficiency may be sufficient. Solar panels are so cheap that if we had affordable, long-term energy storage options, even with such efficiency, we would have completely abandoned fossil fuels. But, unfortunately, storing hydrogen is difficult and dangerous. It is not like natural gas.

> It's not nearly as stupid as making ethanol from corn (which is an energy-negative process) but it's close.

Ethanol is produced from corn not for energy purposes, but for food security. It's like a placeholder for real corn so that if there's a crop failure for a couple of years, the low-iq idiots who think it's stupid to make ethanol from corn don't starve to death.

[aunty_helen]

Your air compressor would get you about 2% of the way to where you need to be whilst also turning any your garage into a bomb.

If you had the knowledge necessary to do this, I would assume that would’ve surfaced reasonably early in the thought process.

[closewith]

No air compressor can compress hydrogen, nowhere near the necessary tip velocity.

[adrianN]

I hope you’re not my neighbor.