Turning carbon dioxide into liquid fuel. Scientists have discovered a new electrocatalyst that converts carbon dioxide (CO2) and water into ethanol with very high energy efficiency, high selectivity for the desired final product and low cost.

[u/Wagamaga]

https://www.anl.gov/article/turning-carbon-dioxide-into-liquid-fuel

[u/spacegardener]

With solar and wind we will often have too much energy and little ways to store it. Using that energy, even with some loss, to capture some carbon to use it as a fuel later is a win-win.
Even if 70% of the energy is lost during the process, that is still 30% energy saved, which would otherwise be lost too.
And each time captured CO2 is used in a fuel new CO2 is not released from the fossils.

[u/[deleted] → u/spacegardener]

Fair enough, I don't know the efficiency of this process, it's possible that it will be great for energy storage.

I'm still sceptical however, because it's an energy intensive process to condense the CO2 to a point where it can be used in this way.

[u/dastardly740 → u/[deleted]]

The goal is sunlight to high density portable energy storage. Usually, that is sunlight to electricity via evaporation, temperature differences between different land areas, or direct to electricity. That part we have a good handle on. It is the electricity to high density portable energy storage that is difficult.

[u/[deleted] → u/dastardly740]

I'm in favor of hydrogen fuel cells, but the volatility problem still needs to be answered.