long duration storage with liquid air

[MikeNovack]

In considering energy storage, the energy/power ratio is important.

This is unlike vehicles. Most current battery development is with batteries where that ratio is < 2-3 hours, and energy density both by weight and volume important. The reason is that such batteries can ALSO be used when the ratio is > 4 and both weight and volume unimportant. There are LOTS of solutions if say ratio =8 and can be both heavy and bulky.

Besides literal batteries, there is current research to make rechargeable zinc-air* "batteries" (actually a "fuel cell") high power. I'm not sure how plays a role, but the old FeNi chemistry involved as well as improving getting air to the air electrode. But for that matter the old FeNi battery still works if the energy/power ratio > 4 hours and you don't care about weight and bulk.

(*) these have excellent energy density but low power. That's OK when you want a tiny "battery" whose charge is used over several days (hearing aid "batteries")

[smegal]

I am going to refrain from giving another Physics lecture. Just mention a few factors folks might want to look up)

1) The critical temperature for O and N (the temperature above which both will remain gasses regardless of how high the pressure)
2) Whether pressure vessels "scale" or not (if a vessel of size X needs walls Y thick to withstand a given pressure, will walls Y thick still be enough if the size becomes 2X? Or will Y have to be increased as the tank becomes larger)
3) Advertised as "long term" storage. What is the problem (what has to be happening to keep "1" from coming into play. How does THAT affect "long term".

This is a scheme where could easily show a working small scale model to potential investors.

It IS a practical scheme for short term storage.

1,2. Critical temperature is sort of irrelevant as One would assume these are at atmospheric pressure. I've worked on a 30,000 m3 cryogenic tank (there are also much larger ones in existence), so scalability isn't a significant concern.

The main issue is the different boiling points of the N2 and O2. This can leave concentrated O2 which is quite hazardous.

3. Long Duration Energy Storage is basically a technology that can discharge for hours (in excess of 4 hours seems to be the definition).

[Stinsy]

3. Long Duration Energy Storage is basically a technology that can discharge for hours (in excess of 4 hours seems to be the definition).

I understood "long duration" in this context to mean inter-seasonal storage. Eg saving solargenerated energy in summer to use in winter!

[smegal]

3. Long Duration Energy Storage is basically a technology that can discharge for hours (in excess of 4 hours seems to be the definition).

I understood "long duration" in this context to mean inter-seasonal storage. Eg saving solargenerated energy in summer to use in winter!

The government definition is 4+ hours.