Comment by ben_w
3 years ago
The best thing hydrogen has going for it is that it’s easy to scale up without needing significant increases in mining and processing various minerals.
If you are willing to increase mining, and want the cheapest solution, and you can ignore or solve geopolitics, the “best” solution is neither hydrogen or batteries, it’s to make a several square meter cross-section HVDC loops around the planet, because nighttime winter is never more than 20 Mm from daytime summer and the losses are low enough that it is still worthwhile.
But: you probably still want hydrogen and batteries for the vehicles, and vehicles use so much power that solving transport almost automatically gives you enough used parts to build the storage capacity for the electricity grid, and that even with batteries (and over-provisioning PV, which is fine because of how cheap it is), there would be enough storage for winter.
> and you can ignore or solve geopolitics
That's a hell of an "if" statement there my friend :)
I agree though, in a thousand years there will be a worldwide electricity grid that takes care of the "big picture" energy flows; hydrogen will be created as needed to serve as chemical feedstock to make eg plastics or hydrocarbons for specialized purposes. That or we kill ourselves in the meantime, but since killing everyone is in nobody's best interest I don't think that'll happen. Hopefully.
> That's a hell of an "if" statement there my friend :)
Indeed! It's one of many reasons that "the best" isn't always the real best.
I'm extremely optimistic about technology, but not so about politics.
> several square meter cross-section HVDC loops
Let's take one half-way around the world.
That's 1 sq m * 20000 km = 20000000 m^3. Let's take aluminum because it's cheap. 2.7 tons/cubic meter = 54 Mt.
Multiply by price: $2444 x 54M = $132B for just the wire. That's $16.5 per capita.
But you also need insulators, labor, machinery, design, and so on.
It’s not that high, if you consider that we consume 150 terra watt hours per year worth of energy. Even if we assume a (unrealistically) low cost of 1 cent per watt hour for transportation, it means we spend at least $1.5T to transport our energy per year.
Extremely cheap! Unfortunately global production is currently 64 Mt/year[0], so the world would need to sustain an increased production for a while. (Especially as square meter cross section is the order-of-magnitude answer, not an exact value).
[0] https://en.wikipedia.org/wiki/List_of_countries_by_primary_a...
The best thing hydrogen has going for it is the cost of energy storage capacity can be as low as $1/kWh (vs. 100x that for batteries.) Underground storage of compressed gases can be very cheap.