I commented in this way because the article directly addressed the problems with the GP comment, and the GP comment made no mention of it. There's also a pattern on HN and elsewhere of comments popping up in top-level threads made in bad faith to derail and redirect conversation, especially on anything related to power generation or renewables. Telling someone to "address the actual content" is precisely what I was doing.
Go use excess PV to pump water uphill back into a reservoir or something if you need energy storage, not drive a complicated process to make artificial hydrocarbons to store in a tank and burn in an engine.
Chemical energy storage is simple, scalable, and allows for the easy movement of vast amounts of energy over great distances to be used anywhere with minimal changes to existing infrastructure.
Chemical storage is horrific. Creating diesel and burning it in a turbine or similar you start at 40-50% for the burning phase, without even converting anything in the first place.
If you go the fuel cell route you tend to end up somewhere at 40-60% efficiency.
So no, the only use case for chemical storage is either where you want energy density. Say aviation or maritime shipping. Or nation state like energy security, where you can pay the efficiency price.
For all other use cases any optimization done, or better usage of the energy, will eat into that horrific round trip efficiency.
Similarly, how bound are you to the local topology? The longest already existing HVDC line in China is 3,293 km (2,046 miles). That brings you from the Rockies to any location within continental US.
Utilize renewables to have bidirectional flow compared to traditional hydro.
either the political will or budget to do this apparently does not exist.
The easiest way to improve transport in the US would be to abolish the TSA and go back to pre-9/11 screening. That would reduce the time needed to arrive before a flight, making flying more competitive for shorter distances. When electric planes are introduced, they'll most likely be for shorter flights at first (since battery tech won't have the range for cross-country or cross-oceanic flights). Then we'll have similar travel times as high speed rail, similar environmental impact, and more flexibility than HSR (since it's easier to fly more/fewer planes to various airports than to build new tracks).
Same reason why a 2 bed in SF is so absurdly priced.
Higher taxes on land will reduce its value - making land purchases cheaper. This will bring American HSR costs more in line with China's.
China also reduces land acquisition costs by building a lot of elevated HSR and reduces overall HSR costs through economies of scale - something that doesnt work when you limit HSR to one area.
Might be able to run off biodiesel or similar. Even if biofuel is double the cost of current dino juice, fuel makes up 20-40% of major airline’s opex, so it’s not like crude-free flying will kill the industry.
Might even be made up with increased aircraft efficiency, more intermediate stop operations (saving 15-30% in fuel by flying 2x medium haul instead of 1x long haul) and better load factors (“revenue management”).
The hydrogen will be electrolysed from water and liquified right at the airport, from power delivered by HVDC lines.
I expect the LH2 tankage will be in under-wing nacelles alongside the engines. Probably existing airframes can be retrofitted.
And one order of magnitude is more than enough. But yeah, besides planes and rockets, hydrocarbons are important in several industrial processes. Besides, we don't want to replace all of the cars, trucks and ships in a single decade.
And the infrastructure used to sequester carbon from the air can be turned around and deployed later when we want to sequester carbon without creating hydrocarbons.