Or we can just follow France's example and build nuclear plants.
If that's legit and can be made cost-effective, the case for nuclear is largely gone...
Come back to me once these claimed figures are actually implemented.
Uhm, well, electrolysis and Sabatier reaction, and then you clean it up and compress it or something. Unfortunately, you need a source of carbon dioxide (no, not air, extracting a trace gas is rather impractical), and then the whole process has a round trip efficiency of certainly no better than 20%. Looks like we need a 4x or so overbuild of unrealiables so that methanation can keep the lights on in winter.
What confuses me is that there are much more practical chemical storage methods nobody talks about. Ammonia comes to mind. It's easier to make and easier to store. I can't help but think that the whole methanation idea is a PR stunt by the gas industry, intended to positively associate renewables with fossil gas in the minds of the unwashed masses.
I've already linked a paper which makes promises of efficiencies of up to 80% using reverse fuel cells.
Here's an older one that promises 'only' 70% efficiency, using caverns for CO2 and CH4 storage:
Not sure how much of these claims will survive after contact with reality...
Those reversible fuel cells... I'll believe in them when I can buy them. And a round trip efficiency of 80% is unbelievable when simple electrolysis of water, which is only half the round trip, isn't that efficient.
(Iñigo Capellán-Pérez, Carlos de Castro, Luis Javier Miguel González,
Dynamic Energy Return on Energy Investment (EROI) and material requirements in scenarios of global transition to renewable energies, Energy Strategy Reviews, Volume 26, 2019, 100399, ISSN 2211-467X, https://doi.org/10.1016/j.esr.2019.100399.)
"Will EROI be the Primary Determinant of Our Economic Future? The View of the Natural Scientist versus the Economist"
Which actually answers why the point you bring up is not relevant:
"In a recent meeting of scientists and economists in London, economists raised eight points as to why it was not necessary to consider EROI in determining future energy availability or policy."
Now the above paper tries to refute those points, but using invalid logic, e.g. arguing that because EROI and costs are linked in oil and gas, then the same observation must hold across categories to renewables.
The red flag that stood out to me is that they show huge increases in tellurium, gallium, and indium demand in Figure 10. Those materials are only required for thin film solar technologies. But according to Table 2, their scenario includes one PV technology: fixed-tilt arrays of silicon PV. Where are the increased demand for tellurium, gallium and indium coming from? It reads like they copy-pasted information from prior studies without paying attention to their own scenario parameters.