Comment by lewis500 | Hacker News Reader

Comment by lewis500 | Hacker News Reader

I always look for the surprising angles in a development of this kind: the knock-on effects. Given 200GW of capacity, in Saudi Arabia, on some days there will be endless electricity.

What I'm thinking is that this will lead to innovation in industrial processes that can productively use a lot of energy in a 4-8 hour window...something you can turn on in a big way and then turn off. Such a process effectively "stores" the energy in the product. The larger the electricity share of such a process, the closer the marginal cost gets to zero during sunny times.

Most modern industrial processes aren't like that: either they're not very power constrained (e.g., a toy factory) or they need the power to be on for a while (e.g., a steel mill). But then again it makes sense these are the types of processing we've perfected, since that's the kind of power we've hard so far in large quantities (coal, nuclear).

Does anyone know of products that can be made quickly by the application of raw energy? I don't know how desalination works, but (just as an example) if there were such a desalination process then Saudi Arabia could desalinate tremendous amounts of water and store it...or even export it to neighbors.

I am not so excited about the idea of a fundamentalist monarchy---one that is helping starve the poor Yemenis---getting even more power, but I am excited about the downstream innovations the fact of nearly-free electricity could potentially create. If SA invents such processes, then they could be copied in other places.

To search for ideas of what would be a good candidate for soaking up excess electricity, look at capital cost per watt consumed:

For instance, if I have an efficient computer system that costs $100 for every watt consumed, it's not going to make sense to run it only during that 20% of the time there's excess electricity. The effective capital cost is then 5 times greater. I'd be better off investing in a battery and extra solar to allow it to run it 24/7.

But if, instead, I have something which has incredibly low capital costs, like 10 cents per Watt consumed, and which can tolerate being shutdown and restarted, then even though it might only be operating 20% of the time, the effective capital cost is still just 50 cents per Watt, even cheaper than a battery capital cost. So it makes economic sense to use that to soak up the extra electricity demand.

This is why the key for hydrogen electrolysis isn't so much efficiency but capital costs: a variable-renewables-heavy grid will have enormous amounts of excess electricity at times, but only for fairly brief periods. You can't economically "store" that electricity using hydrogen if your electrolysis capital costs are so high you need to run your electrolysis cell 24/7!

If you want to make the hydrogen economy a reality, FORGET about hydrogen cars. Focus on hydrogen electrolysis capital costs!!!

I suspect the best option is pumping sea water up the sides of a mountains in the south west for pumped storage. Except rather than then using it to run generators they use that same pressure to operate desalination plants 24/7.

Reverse osmosis uses (600–1200 psi) for seawater = 1400 to 2800 feet of elevation which is taller than what they have available, but sill very viable. Further, as reverse osmosis already needs to pump salt water to high pressure the only change is simply slightly larger pumps and a big pit plus some piping for massive amounts of energy storage.

Great point. They're not doing it to save the world or anything, they see dollar signs. As you said, they'll desalinate enormous amounts of water, and that is life.

While $200b is about $200b more than virtually all of us have, all the Crown Prince has to do is hold another Ritz Carlton party. This time they know he's serious so they'll pay in a few days.

Aluminum smelting.

Desalination is a good idea too, but instead of selling the water they could use it to grow forests and then sell carbon credits.

Growing forests would be incredible, it’d be like rain forest eventually right? It would be very strange to see a substantially green country in the Middle East.

But to do that you need to increase the salinity of the nearby ocean for years.

How much of the increase in salinity stays? The ocean is huge and the water moves so I'm surprised that desalination has a large effect in that regard

I don't know. I live on the other side of the continent from California but sometimes I hear complaints about the ecological impact. http://www.latimes.com/business/hiltzik/la-fi-hiltzik-201504... The oceans may be deep in the middle, but they are often shallow at the edges. And Saudia Arabia is bordered by two seas which have much less capacity to dilute salt than an open ocean.

I think “the Earth is huge” is one of those things that makes intuitive sense to us, but that fails to take in to account the scale with which we operate. A desalination plant must put a lot of excess salt into the ocean somewhere. Whenever you’re dumping high quantities of something into the ocean, there’s always going to be some effect. The question is just “how significant” is the effect. I assume the local animal population could perhaps be greatly affected. And depending on the region there could be effects on migrating populations as well. Everything we do has an impact.

But where will they train their Sardaukar?

The smelted aluminium goes to the market, recyclable aluminium from scrap is recovered and fed into grid scale aluminium air batteries (still in development) and you have got a closed loop of generation and storage.

Aluminum smelting does NOT handle shutdowns very well, though. Aluminum smelting really needs a constant power source because shutdowns can actually damage the electrolysis pots.

Crypto mining?

More seriously, it will boots/create R&D for actual energy storage. Storing it in products might be nice early one, but having application neutral (renewable) energy available whenever for whatever we want seems like an unavoidable trend.

on good days they could pump water into silos

>Does anyone know of products that can be made quickly by the application of raw energy?

Chipsets?

Potato chipsets?

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