long duration storage with liquid air

[Bugtownboy]

Next time you go to a reasonably sized hospital, look for the liquid oxygen tanks nearby one of the more ‘facilities’ type areas.

They are large and usually in multiples - they’ll supply the oxygen supply around the hospital.

In a previous life, I used to have multiple Dewars storing liquid Nitrogen (used to process and store ‘bone marrow’ / stem cells )

Liquid ‘air’ is already stored probably near to all of us - how many hospital sized ‘Dewars’ would be needed to provide energy storage, don’t know, but I’m sure from a storage perspective, scaleability shouldnt be an issue.

[Countrypaul]

Before going to university I worked over summer at a chemical site. On site they had 2 spherical storage spheres for liquified gas (iirc it was Propene), not sure but I seem to recollect these were 90ft in diameter, but the gas/liquid was not stored under pressure. The gas above the liquid was constantly removed and reliquified before being pumped back into the storage sphere. Both storge sphere had pressure release valves (not surprising). On one occasion there was a failure in the cooling system resulting in the PRV lifting for around 90 seconds. The main concern was whether the few tonsof gas released was enough to form an explosive cloud that wouldmake its way across the estuary to the town on the other side as an explosive mixture. Due to the weather it didn't and dispersed out to sea rather quicker than was expected.

The schematic on the Highview website also shows a Regassification stage with a link to the High Grade Cold store, so it might be that they are using a similar approach. The first gas to come off liquid air as it warms is oxygen, a high concentration of which can cause serious problems. There have been incidents in labs using liquid nitrogen in condensers where explosions have resulted because of oxygen condensing out of the air and dripping onto organic compounds below.

[Moxi]

Every large steel making plant has an on site air distillation plant to produce oxygen for steel making, nitrogen and other gases are sold on to third parties and argon is used on site for bubbling through the steel when alloying.

Moxi

[MikeNovack]

Before going to university I worked over summer at a chemical site. On site they had 2 spherical storage spheres for liquified gas (iirc it was Propene),

The critical temperature of propane is a little under 100C. If you fill a pressure vessel with liquid propane and close the valve, some of it will remain liquid if at ambient temperature. The vessel would have to be able to withstand a bit over 600 psi.

[Countrypaul]

Before going to university I worked over summer at a chemical site. On site they had 2 spherical storage spheres for liquified gas (iirc it was Propene),

The critical temperature of propane is a little under 100C. If you fill a pressure vessel with liquid propane and close the valve, some of it will remain liquid if at ambient temperature. The vessel would have to be able to withstand a bit over 600 psi.

Propane is different to Propene (used to be called propylene) although the critical temperature is only just slightly lower.

A 90ft diameter sphere would have to withstand about 4oo tons force for each 1 PSI, not surprising the PRV lifted so quicky when things went in the wrong direction.

[Paul_F]

Don't we have (or had) loads of air liquification and distillation plants around the UK...?
I'm sure I have seen lorries of liquid N₂ on the road and delivering to scientific/research facilities - and liquid oxygen is also a regular thing. I have even done jobs on sites where other people have brought big Dewar flasks of liquid N₂ in their cars to cool the sensors in their instruments... Why suggest it might be in the "too difficult" category? I think that well-insulated (vented/cryogenic) storage of liquid air is well-established, probably since the Victorian era.

Those systems work by using the latent heat extracted by the boil-off gas to keep the rest liquid. As a convenient self-regulating system it's great, but the losses are significant. Acceptable when liquid nitrogen is cheap to use and adds a lot of value to industrial processes, but not great for an energy storage scheme - particularly one where you're looking to store energy for long term (i.e. inter-seasonal) use.

[AE-NMidlands]

Don't we have (or had) loads of air liquification and distillation plants around the UK...?
I'm sure I have seen lorries of liquid N₂ on the road and delivering to scientific/research facilities - and liquid oxygen is also a regular thing. I have even done jobs on sites where other people have brought big Dewar flasks of liquid N₂ in their cars to cool the sensors in their instruments... Why suggest it might be in the "too difficult" category? I think that well-insulated (vented/cryogenic) storage of liquid air is well-established, probably since the Victorian era.

Those systems work by using the latent heat extracted by the boil-off gas to keep the rest liquid. As a convenient self-regulating system it's great, but the losses are significant. Acceptable when liquid nitrogen is cheap to use and adds a lot of value to industrial processes, but not great for an energy storage scheme - particularly one where you're looking to store energy for long term (i.e. inter-seasonal) use.

Are you agreeing with MikeNowak - who seems to be saying that scaling this up won't work because (if I understood it right) large volume storage of liquid air demands such high pressure that the container becomes either unbuildable or disproportionately expensive?
If that's so it's a pity, as it looked a clever use of straightforward engineering and clean materials.

[Mart]

Don't we have (or had) loads of air liquification and distillation plants around the UK...?
I'm sure I have seen lorries of liquid N₂ on the road and delivering to scientific/research facilities - and liquid oxygen is also a regular thing. I have even done jobs on sites where other people have brought big Dewar flasks of liquid N₂ in their cars to cool the sensors in their instruments... Why suggest it might be in the "too difficult" category? I think that well-insulated (vented/cryogenic) storage of liquid air is well-established, probably since the Victorian era.

Those systems work by using the latent heat extracted by the boil-off gas to keep the rest liquid. As a convenient self-regulating system it's great, but the losses are significant. Acceptable when liquid nitrogen is cheap to use and adds a lot of value to industrial processes, but not great for an energy storage scheme - particularly one where you're looking to store energy for long term (i.e. inter-seasonal) use.

Hiya. I don't believe LAES is aiming for inter-seasonal storage*, it's more in the shorter end of LDES, like flow batts. And even if we have 100's of them, which is entirely possible, that will 'only' be a few 100GWh's, which again is more for intra-day grid balancing.

For longer LDES roles, we are probably looking at CAES, if it's viable and economic, if only for scale (in the TWh's range). Combined perhaps with a broader range of technology, such as tidal, interconnectors, and the current use of bio-mass/bio-energy to demand follow, as it has an element of multi-day storage. Even schemes like the Morrocco interconnector, with reliable power, may be considered as part of a wider storage plan, or at least having an impact on the total needed.


*In fact, I don't think the UK/most of Europe are even considering inter-seasonal storage for leccy, since we have a good balance of PV and wind. So 2-3 weeks may be the max. Inter-seasonal heat batteries, may be a thing, assuming the economics work out, but that's a slightly different role.

[Paul_F]

Are you agreeing with MikeNowak - who seems to be saying that scaling this up won't work because (if I understood it right) large volume storage of liquid air demands such high pressure that the container becomes either unbuildable or disproportionately expensive?
If that's so it's a pity, as it looked a clever use of straightforward engineering and clean materials.

Slightly different view from me - I don't believe that it would ever be pressurised (safety case would be nightmarish and expensive as a result), but I think the losses from storing it more than a couple of days would be prohibitive.
The problem is when you're only storing for a few hours the rapid response and high C-rate of batteries starts to become more attractive than the low capital cost per MWh of liquid air tanks. Given that the cost per MWh of batteries is crashing, I think this is an interesting idea that just isn't economically viable.

[Mart]

Are you agreeing with MikeNowak - who seems to be saying that scaling this up won't work because (if I understood it right) large volume storage of liquid air demands such high pressure that the container becomes either unbuildable or disproportionately expensive?
If that's so it's a pity, as it looked a clever use of straightforward engineering and clean materials.

Slightly different view from me - I don't believe that it would ever be pressurised (safety case would be nightmarish and expensive as a result), but I think the losses from storing it more than a couple of days would be prohibitive.
The problem is when you're only storing for a few hours the rapid response and high C-rate of batteries starts to become more attractive than the low capital cost per MWh of liquid air tanks. Given that the cost per MWh of batteries is crashing, I think this is an interesting idea that just isn't economically viable.

Good points, I think the UK recently re-classified, or made more clear that LDES should be minimum 6hr, and OFGEM suggesting it's raised to 8hr or 10hr minimum.

Part of that, is exactly what you suggest, that the rapidly falling cost of lithium batts (and possibly similar like Sodium), is allowing for them to economically compete in roles greater than their previous (economic) speciality of 1-4hrs.

I really like the idea of LAES, and have had a massive soft spot for Highview for over a decade, but I don't know if any of their costs will fall over time, as the technology/kit is already well established.

Still, more options is better than less.