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I really wish humanity comes up with a good way to store large quantities of electricity (not counting Hydro Batteries). Compressed air in mines is a good alte

I really wish humanity comes up with a good way to store large quantities of electricity (not counting Hydro Batteries). Compressed air in mines is a good alternative, with heat of compression also stored. I am actually looking for ways to make this small scale. As in, creating a storage system for domestic use. In developing countries, average energy usage per house hold, would be not more than 10 kWh per day. Compressed air is slightly dangerous, so are flywheel systems, not to mention complexity of operation. Chemical conversion of captured carbon to liquid fuels seems to be a viable solution.

jedimastert 6y ago
> I am actually looking for ways to make this small scale. As in, creating a storage system for domestic use. Mildly interesting thought: grandfather clocks have been using this form of battery for a very long time
Tade0 6y ago
We already have that in the form of LiFePO4 batteries. They last over 2000+ cycles, use no rare/expensive/conflict minerals and are safe. Also just recently they crossed the $100/kWh barrier in some markets: https://about.bnef.com/blog/battery-pack-prices-cited-below-100-kwh-for-the-first-time-in-2020-while-market-average-sits-at-137-kwh/ https://about.bnef.com/blog/battery-pack-prices-cited-below-... An ISO container(40ft) of those can store 10-15MWh. For the cost of the Astravets Nuclear Power Plant in Belarus ($11bln, 2GW) you could have 80GWh worth of batteries - that's a week of backup power for one million households in the EU. One disadvantage of them has always been their performance in terms of power and energy density, but given that they're currently installed in Chinese-made Teslas, I guess it's more or less a solved problem.
- newyankee 6y ago
  i have never seen retail prices of lfp batteries below 300$/kwh yet. Although i am confident near future versions of these batteries can last > 5k and may be even 10k cycles
  - Tade0 6y ago
    I studied the topic and it appears that none of the manufacturers/retailers is willing to sell at this price to consumers - they already sell all their stock to car manufacturers and the like.
    - newyankee 6y ago
      Is it because demand greatly outstrips supply at this point and will remain so for a few more years at least till new production capacity catches up ? Or is there any other reason that makes it trickier ? Would appreciate any links if you have some.
      - Tade0 6y ago
        My best source was a first-hand account from a business owner who tried to switch from one-off EV projects to an a full-blown assembly line. He called up a few manufacturers and they basically told him to come back when he's at the scale of hundreds of MWh - sort of a chicken-and-egg scenario. Retailers didn't want to talk about special pricing, regardless of scale.
- baybal2 6y ago
  I came to very much the same conclusion few weeks ago https://news.ycombinator.com/item?id=25651782 https://news.ycombinator.com/item?id=25651782 The basic math behind the company simply doesn't work. They cannot make money out of it.
dmos62 6y ago
I've read about using a lot of small cheap containers, like plastic bottles, as compressed air batteries, but can't find the article right now. Apparenly a lot of small containers is a significant improvement over few (or single) large compressed air containers. Many small containers offer better space efficiency, they're cheaper, because you require less pressure (regular plastic bottles v. steel tanks), and their power output is steadier.
- nullsmack 6y ago
  There's this article about using small containers: https://solar.lowtechmagazine.com/2018/05/ditch-the-batteries-off-grid-compressed-air-energy-storage.html https://solar.lowtechmagazine.com/2018/05/ditch-the-batterie... But it's not talking about using cheap things like plastic bottles. I'd be interested in reading the article you're talking about. It's hard to find much about CAES online because it's easy to run into the crazy people that think they're going to get free energy out of it or something.

jedimastert 6y ago

> I am actually looking for ways to make this small scale. As in, creating a storage system for domestic use. Mildly interesting thought: grandfather clocks have been using this form of battery for a very long time

Tade0 6y ago

We already have that in the form of LiFePO4 batteries. They last over 2000+ cycles, use no rare/expensive/conflict minerals and are safe. Also just recently they crossed the $100/kWh barrier in some markets: https://about.bnef.com/blog/battery-pack-prices-cited-below-100-kwh-for-the-first-time-in-2020-while-market-average-sits-at-137-kwh/ https://about.bnef.com/blog/battery-pack-prices-cited-below-... An ISO container(40ft) of those can store 10-15MWh. For the cost of the Astravets Nuclear Power Plant in Belarus ($11bln, 2GW) you could have 80GWh worth of batteries - that's a week of backup power for one million households in the EU. One disadvantage of them has always been their performance in terms of power and energy density, but given that they're currently installed in Chinese-made Teslas, I guess it's more or less a solved problem.

newyankee 6y ago
i have never seen retail prices of lfp batteries below 300$/kwh yet. Although i am confident near future versions of these batteries can last > 5k and may be even 10k cycles
- Tade0 6y ago
  I studied the topic and it appears that none of the manufacturers/retailers is willing to sell at this price to consumers - they already sell all their stock to car manufacturers and the like.
  - newyankee 6y ago
    Is it because demand greatly outstrips supply at this point and will remain so for a few more years at least till new production capacity catches up ? Or is there any other reason that makes it trickier ? Would appreciate any links if you have some.
    - Tade0 6y ago
      My best source was a first-hand account from a business owner who tried to switch from one-off EV projects to an a full-blown assembly line. He called up a few manufacturers and they basically told him to come back when he's at the scale of hundreds of MWh - sort of a chicken-and-egg scenario. Retailers didn't want to talk about special pricing, regardless of scale.
baybal2 6y ago
I came to very much the same conclusion few weeks ago https://news.ycombinator.com/item?id=25651782 https://news.ycombinator.com/item?id=25651782 The basic math behind the company simply doesn't work. They cannot make money out of it.

dmos62 6y ago

I've read about using a lot of small cheap containers, like plastic bottles, as compressed air batteries, but can't find the article right now. Apparenly a lot of small containers is a significant improvement over few (or single) large compressed air containers. Many small containers offer better space efficiency, they're cheaper, because you require less pressure (regular plastic bottles v. steel tanks), and their power output is steadier.

nullsmack 6y ago
There's this article about using small containers: https://solar.lowtechmagazine.com/2018/05/ditch-the-batteries-off-grid-compressed-air-energy-storage.html https://solar.lowtechmagazine.com/2018/05/ditch-the-batterie... But it's not talking about using cheap things like plastic bottles. I'd be interested in reading the article you're talking about. It's hard to find much about CAES online because it's easy to run into the crazy people that think they're going to get free energy out of it or something.