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>The new liquid air battery, being developed by Highview Power, is due to be operational in 2022 and will be able to power up to 200,000 homes for five hours, a

>The new liquid air battery, being developed by Highview Power, is due to be operational in 2022 and will be able to power up to 200,000 homes for five hours, and store power for many weeks. Is it just they're expecting many leaks in the system? I don't see why they couldn't just store things for years basically.

icegreentea2 6y ago
Liquid air is cryogenic - they'll have to either bleed off or spend energy to keep it cooled. The "many weeks" measurements is probably some measurement of bleed off rate assuming no top offs (but I'm just guessing - the company website https://www.highviewpower.com/technology/ https://www.highviewpower.com/technology/ doesn't seem to call it out clearly).
- imposterr 6y ago
  If the tanks are strong enough, is cooling required? My understanding is that you'd only need to cool the liquid if the structure holding it wasn't sufficiently strong enough to handle the pressures.
  - icegreentea2 6y ago
    Approximating air as nitrogen... nitrogen cannot exist as liquid phase at room temperature - it can exist as a supercritical fluid though at 5MPa (so 50 atm). At that point it has a density of roughly 56 kg/m^3. At ~1 atm, nitrogen becomes liquid at -194C and has a density of roughly 800 kg/m^3. So your mass density of the system is like 14 times better with liquid nitrogen, and the pressure loading requirements are stupidly lower.
  - deleted 6y ago
    [deleted]
  - woodandsteel 6y ago
    Making the tanks strong enough to handle the pressure if the liquid turns to gas is very expensive. It is much cheaper to make a tank that just holds a liquid.
mhandley 6y ago
It's not cost effective to store for a very long time. If you stored for a year, and the tanks last 30 years, you only get 30 tanks worth of electricity for the price of the tank. If you store for a few hours, you get 30*365 tanks worth of electricity for the price of the tank, but you need to factor in the cost of the compressor and generator. Presumably there's some balance when you're getting best value out of the compressor and generator, but don't need an excessive number of tanks.

icegreentea2 6y ago

Liquid air is cryogenic - they'll have to either bleed off or spend energy to keep it cooled. The "many weeks" measurements is probably some measurement of bleed off rate assuming no top offs (but I'm just guessing - the company website https://www.highviewpower.com/technology/ https://www.highviewpower.com/technology/ doesn't seem to call it out clearly).

imposterr 6y ago
If the tanks are strong enough, is cooling required? My understanding is that you'd only need to cool the liquid if the structure holding it wasn't sufficiently strong enough to handle the pressures.
- icegreentea2 6y ago
  Approximating air as nitrogen... nitrogen cannot exist as liquid phase at room temperature - it can exist as a supercritical fluid though at 5MPa (so 50 atm). At that point it has a density of roughly 56 kg/m^3. At ~1 atm, nitrogen becomes liquid at -194C and has a density of roughly 800 kg/m^3. So your mass density of the system is like 14 times better with liquid nitrogen, and the pressure loading requirements are stupidly lower.
- deleted 6y ago
  [deleted]
- woodandsteel 6y ago
  Making the tanks strong enough to handle the pressure if the liquid turns to gas is very expensive. It is much cheaper to make a tank that just holds a liquid.

mhandley 6y ago

It's not cost effective to store for a very long time. If you stored for a year, and the tanks last 30 years, you only get 30 tanks worth of electricity for the price of the tank. If you store for a few hours, you get 30*365 tanks worth of electricity for the price of the tank, but you need to factor in the cost of the compressor and generator. Presumably there's some balance when you're getting best value out of the compressor and generator, but don't need an excessive number of tanks.