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'Freeze-thaw battery' stores electricity long-term for seasonal release

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Re: 'Freeze-thaw battery' stores electricity long-term for seasonal release

#11

Post by jewel »

phh wrote: post #7

It doesn't sound like the improvement of cost is enough the justify using it only for few cycles a year as the title says rather than every other day. That said, I see nothing in this article saying why it would be limited to seasonal release, I'm guessing it just has a lower self-discharge. The title made me thought of an idea my father had, for which I'm still totally ambivalent: Freeze water in the cellar (speakin…

Your father's idea is a good one. Here is a thermal heat pit which is being used to store heat for the winter:

https://stateofgreen.com/en/partners/ramboll/solutions/world...

Re: 'Freeze-thaw battery' stores electricity long-term for seasonal release

#12

Post by maxerickson »

seltzered_ wrote: post #5

"The freeze-thaw phenomenon is possible because the battery’s electrolyte is molten salt - a molecular cousin of ordinary table salt. The material is liquid at higher temperatures but solid at room temperature. The freeze-thaw battery was shown to retain 92 per cent of its capacity over 12 weeks." Any relation between this and 'sodium-ion' battery companies like the recently acquired Faradion? (see https://www.youtub…

The electrolyte is sodium aluminum and chlorine, which sounds pretty different than sodium-ion.

https://www.sciencedirect.com/science/article/pii/S266638642...

The PNNL article is somewhat better than the current link.

https://www.pnnl.gov/news-media/freeze-thaw-battery-adept-pr...

Re: 'Freeze-thaw battery' stores electricity long-term for seasonal release

#13

Post by Haplo »

phh wrote: post #7

It doesn't sound like the improvement of cost is enough the justify using it only for few cycles a year as the title says rather than every other day. That said, I see nothing in this article saying why it would be limited to seasonal release, I'm guessing it just has a lower self-discharge. The title made me thought of an idea my father had, for which I'm still totally ambivalent: Freeze water in the cellar (speakin…

Similar systems are actually being build, but with a bigger scale (like big office buildings). There is no freezing involved, just heating the office space with warm water in the winter (cooling the water to ~10°C) and cooling it in the summer (heating the water to about 40°C).

Re: 'Freeze-thaw battery' stores electricity long-term for seasonal release

#14

Post by KaiserPro »

gwbas1c wrote: post #8

> The battery’s theoretical energy density is 260 watt-hours per kilogram Makes me wonder how big a battery would need to be to handle all of the overwinter energy demands of some densely-populated US states.

Massive. But I don't think thats the point of this.

I imagine you'd pair this with an energy source(say solar), so that you are able to smooth out/absorb excess energy and release when its needed. You could use it as an energy supply of last resort.

Re: 'Freeze-thaw battery' stores electricity long-term for seasonal release

#15

Post by KennyBlanken »

Iron flow batteries already exist commercially, are even more non-toxic/safe, and they don't require heating up (and keeping hot, while using) the battery.

https://essinc.com/iron-flow-chemistry/

The utility industry isn't really that interested in storing power for an entire season. Very little ROI compared to a system that allows them to balance minute-to-minute or day/night...or transmission infrastructure improvements. Got excess generating capacity? Send it somewhere that doesn't.

I hope that some day in the near future we see home-scale or neighborhood-scale iron flow battery systems so that homeowners, apartment buildings, and small neighborhoods can go off-grid.

Re: 'Freeze-thaw battery' stores electricity long-term for seasonal release

#16

Post by KennyBlanken »

phh wrote: post #7

It doesn't sound like the improvement of cost is enough the justify using it only for few cycles a year as the title says rather than every other day. That said, I see nothing in this article saying why it would be limited to seasonal release, I'm guessing it just has a lower self-discharge. The title made me thought of an idea my father had, for which I'm still totally ambivalent: Freeze water in the cellar (speakin…

> some other people would have already proposed such things.

Geothermal heat pumps. Been around for decades. Expensive to install due to drilling the well or laying the field, but very efficient.

Re: 'Freeze-thaw battery' stores electricity long-term for seasonal release

#17

Post by a9h74j »

Tangent, but in the seasonal storage context.

Apparently, according to a reported simulation, if you (1) take a ca 15m x 15m house thermally in contact with the ground, (2) insulate the ground outside to a radius of ca 40m, and (3) heat the interior to say 25C, then (4) evenually (50years?) the ground itself under the house will come up to a steady temperature consistent with that.

Even if the simulation was correct, I can only see this being sustainable with solar gain being used for heating, but it makes for an interesting long-term-oriented picture.

One imaginable scale of application could be for a cluster of houses in a larger agricultural setting.

Re: 'Freeze-thaw battery' stores electricity long-term for seasonal release

#18

Post by Gasp0de »

phh wrote: post #7

It doesn't sound like the improvement of cost is enough the justify using it only for few cycles a year as the title says rather than every other day. That said, I see nothing in this article saying why it would be limited to seasonal release, I'm guessing it just has a lower self-discharge. The title made me thought of an idea my father had, for which I'm still totally ambivalent: Freeze water in the cellar (speakin…

This exists and is actually used in Germany, it is called "Eisspeicher" (ice storage). It is utilizing the effect that it takes a huge amount of energy for the water to go from solid to fluid, about the equivalent of heating water from 1 to 81 degrees.

Re: 'Freeze-thaw battery' stores electricity long-term for seasonal release

#19

Post by Gasp0de »

This doesn't seem cost efficient at all, my (medium sized) house in Germany consumes about 3000kWh of electricity during winter. This does not include heating, which consumes another 15.000kWh (of heat energy from oil, so around 5000kWh electrical energy with a heat pump).

If I were to use this battery I would need to get 3000(8000)kWh of energy storage at 23$ per kWh which would amount to 69000(184000)$. There are better hydrogen-based solutions for that cost. Also, did I read correctly that I have to keep the battery heated to 180°C during discharge? This is going to waste a lot of energy in winter.

Re: 'Freeze-thaw battery' stores electricity long-term for seasonal release

#20

Post by gwbas1c »

Gasp0de wrote: post #19

This doesn't seem cost efficient at all, my (medium sized) house in Germany consumes about 3000kWh of electricity during winter. This does not include heating, which consumes another 15.000kWh (of heat energy from oil, so around 5000kWh electrical energy with a heat pump). If I were to use this battery I would need to get 3000(8000)kWh of energy storage at 23$ per kWh which would amount to 69000(184000)$. There are b…

Gosh, it's still coming out of academia. It takes awhile before these kinds of things are economically viable.
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