The ability of higher efficiency technologies to perform many more profitable trades in a given year has a significant impact on ROI.
https://www.researchgate.net/publication/341393321/figure/fi...
What we should be doing though is building this smart charging and dispatch functionality into cars, so that we don't make our existing electricity peaks even peakier when people get home from work and immediately plug in and charge their EVs.
Ideally people would charge their cars at work, during the day. I guess we need to lean on employers with huge parking lots to provide EV charging.
What does it matter you lose 20% if the alternative is selling at a loss?
Another way to say this is that there is a real economical value for storage because of the increase in renewables
[1] https://www.rte-france.com/eco2mix/les-donnees-de-marche
The alternative isn't selling at a loss, it's using technology with higher round trip efficiency.
Say you have two batteries, both 1MW/4H systems, one lithium at 95% efficiency, one this CO2 thing at 80% effiency. In the highly volatile SE4 spot region in the Scandinavian grid, if you traded in 2019 you'd have made $80K USD with the CO2 battery, $155K USD with the Lithium one (assuming you traded perfectly).
A tigher efficiency envelope lets you exploit many smaller 10-20% cost gaps, rather than having to sit for many days to wait for gaps in the 30-40% range.
Not to say that Lithium would have a higher ROI over all than this technology, just to say that round trip efficiencies have significant impact on revenues here.
Such short bursts of energy are typical for Li-Ion batteries, but quite atypical for other forms of energy. It's the same principle as with the flow batteries.