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The article acts like hydrogen from electrolysis is an energy source, but this side of fusion (and fusion has remained 30 years in the future for nearly a centu

by dublin 4y ago

The article acts like hydrogen from electrolysis is an energy source, but this side of fusion (and fusion has remained 30 years in the future for nearly a century now...), hydrogen is really an energy storage mechanism, not an energy source. The reason the vast majority of the world's hydrogen comes from natural gas (or the very similar coal gas) is due to two simple facts: 1) Natural gas (methane) conveniently has 4 hydrogen atoms and only one carbon atom, so it's by far the best/easiest/cheapest source of hydrogen there is; 2) Water is one of the most stable molecules in the universe - it requires enormous energy to rip apart, so electrolysis takes a LOT of energy, and that energy (in the form of electricity) has to come from somewhere itself: Currently the most cost effective source is, once again, natural gas. Nuclear (fission) electricity would help a lot (for those who are foolish enough to think that CO2 is a pollutant), but the hippie greenies insist on scuttling the highest-capacity, lowest-carbon energy source we know of...

ncmncm 4y ago
It is correct to say hydrogen is principally a storage medium, although its use as direct feedstock will always be comparably important. The rest is questionable. You get back the ("enormous") energy used to strip oxygen off of water molecules, yielding hydrogen, when you react the hydrogen again with oxygen. Of course by far the most cost-effective way to generate that ("enormous") energy is with enormously cheap solar panels and wind turbines. (The round-trip efficiency of hydrolysis and combustion is fairly low because the hydrogen recombines to H2, yielding heat during electrolysis, then the hydrogen may need to be liquified for transport, and then the H2 may need to be split again when making H2O. Perhaps surprisingly, low round-trip efficiency doesn't matter very much because solar has become so cheap; you just add more panels to make up the difference.) There is no plausible scenario where fusion or fission provides a substantial fraction of the energy used. Fission is enormously more expensive than renewables for the same output -- beyond order-of-magnitude more expensive. Fusion, if ever made to work, would cost another order of magnitude beyond that. Things >100x as expensive as practical alternatives are rarely seen used. AA batteries and bottled beverages are exceptions. And, of course CO2 is a pollutant. The most dominant one, it has turned out. Taxing release of it, and the revenue used to build out renewables, storage, and transmission lines cannot come soon enough.

by dublin 4y ago

ncmncm 4y ago

It is correct to say hydrogen is principally a storage medium, although its use as direct feedstock will always be comparably important. The rest is questionable. You get back the ("enormous") energy used to strip oxygen off of water molecules, yielding hydrogen, when you react the hydrogen again with oxygen. Of course by far the most cost-effective way to generate that ("enormous") energy is with enormously cheap solar panels and wind turbines. (The round-trip efficiency of hydrolysis and combustion is fairly low because the hydrogen recombines to H2, yielding heat during electrolysis, then the hydrogen may need to be liquified for transport, and then the H2 may need to be split again when making H2O. Perhaps surprisingly, low round-trip efficiency doesn't matter very much because solar has become so cheap; you just add more panels to make up the difference.) There is no plausible scenario where fusion or fission provides a substantial fraction of the energy used. Fission is enormously more expensive than renewables for the same output -- beyond order-of-magnitude more expensive. Fusion, if ever made to work, would cost another order of magnitude beyond that. Things >100x as expensive as practical alternatives are rarely seen used. AA batteries and bottled beverages are exceptions. And, of course CO2 is a pollutant. The most dominant one, it has turned out. Taxing release of it, and the revenue used to build out renewables, storage, and transmission lines cannot come soon enough.