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I do not understand why there is not more focus on fuel synthesis. If electricity becomes “free” for hours a day, even crummy roundtrip efficiency seems like a great option to soak up extra capacity and get long term (seasonal?) storage.



You are describing e-fuels. Hydrogen from excess renewables is the same idea. The critics are simply not paying attention to the fact that green energy is nearly free and therefore fuels made from it can also be nearly free.


The plants aren't free.


Same issue with wind and solar. Sure, you have to build them first, but afterwards it's a continuous stream of virtually free energy.


How much is virtually free?

How much will each kWh generated from synthetic fuels cost?


As free as green electricity itself. You're just reusing the same attacks that were used against wind and solar.


Asking questions is attacking, now is it? What are we, snowflakes?

Can you please answer the question with dollars and cents? Or if you don't know, say so.

Green electricity isn't free. Neither will synthetic fuels be.


Is green electricity suppose to be nonviable now? If you can accept that green electricity, which will be the dominate source of unexpected cost, is going to be very cheap, then anything predominately made from it will also be very cheap.

This is a repeat of the anti-wind and solar attacks because it is the same general principle. Basically an appeal to the unknown that the new green technology couldn't possibly be cheap, despite plenty of evidence that cost is dropping or that there is no expensive supply chain.


Can you run fuel synthesis profitably purely on intermittent renewable power and scale up and down in real-time?

Capital costs are high and utilization will be low.


The key is sufficiently cheap electrolysers. They are below $300/kW now. The other steps (if any) have higher capital cost/energy cost ratios, so they can be done when energy is more expensive.


Can you explain how the costs pencil out?

Today, in Finland, renewables produced between 0,2 GW and 1,5 GW.

Does that mean I would need $450M (1,5 GW * $300/kW) in electrolysers to soak up all that power?

For simplicity's sake, let's say output averages 1GW over 24 hours? What do I get for the day with my $450M electrolysis plant?


There's a tradeoff between the cost of excess solar/wind and the capacity factor of the electrolysers. You can get a handle on where the tradeoffs lie by looking at optimizations using historical weather data.

https://model.energy/

For Finland, the 2030 assumptions number (for "synthetic baseload" from renewables + storage) is just under their "EPR" number (which may be a bit optimistic, given your experience with an EPR). As I said, Finland is a tough case for renewables. The solution has > 400 MW each of solar and wind, and 110 MW of electrolysers (to provide 100 MW of synthetic baseload).


That's a very interesting site.

I got Average system cost [EUR/MWh]: 101.9 which is more than nuclear, when solving for renewables + storage + hydrogen.


As I said, Finland is one of the worst locations for renewables. There, nuclear remains at least within spitting distance of being competitive.

But as I also said elsewhere in these comments, this just means Finland (and other nearby countries at high latitude and without good wind resources) will become energy ghettos. They will lose their energy intensive industries. You will not be able to compete in such industries with countries where solar seasonality is low and insolation is very high. This means your energy consumption per capita will be depressed. Can a nuclear industry survive powering a handful of such disadvantaged countries? Maybe they'll just import energy from elsewhere (hydrogen can be piped like natural gas; while it has less energy per unit volume it also has considerably lower viscosity, reducing pumping costs.)


Sort of. Doing that would still be cheaper than nuclear power whose capital costs are insane. Does that count as profitable?

It would be cheaper still to throw pumped storage and batteries into the mix.


> Sort of. Doing that would still be cheaper than nuclear power whose capital costs are insane. Does that count as profitable?

Yes. What do I get for $15B? How many GWh of storage and electricity generation?

> It would be cheaper still to throw pumped storage and batteries into the mix.

What pumped storate? Everybody is already about maxed out on hydro capability.

What batteries? The world is barely producing enough for EVs and other stuff, there aren't enough GWhs available for utility storage.


> What pumped storate? Everybody is already about maxed out on hydro capability.

You are making the common mistake of assuming pumped hydro must, like primary hydro, be built on rivers. But pumped hydro just requires two reservoirs near each other with a vertical offset (although one can imagine repurposing an existing on-river reservoir by adding a separate off-river reservoir nearby at a different altitude; any reservoir with a sizeable hill nearby would do.) They could be built anywhere that isn't flat, even in deserts.

This web site uses geographical data to find PHES opportunities around the world. The possibilities are enormous.

https://re100.eng.anu.edu.au/global/

As an example, here's a facility being built near Ely, Nevada. Look how arid the area is. This facility is sized to provide 1000 MW of output for 8 hours. At $2.5B, the cost of the project is ~$316/kWh of storage capacity.

https://www.powermag.com/major-pumped-hydro-storage-project-...

> What batteries? The world is barely producing enough for EVs and other stuff, there aren't enough GWhs available for utility storage.

You are again making a foolish argument that production of things cannot be increased. Please stop. One would almost begin to think you're arguing in bad faith here.




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