Lithium-ion batteries are falling in cost so rapidly that any new process being ramped up is risky business. Form is way further along than this landing page and yet has a long way to go:
A gas-based design seems like it would be better at a small scale - e.g. the facility in the link has a reservoir the better part of a mile away from the turbines, and has a max output of 600 MW or so.
CO2 may actually be a good working fluid for the purpose - cheap, non-toxic except for suffocation hazard, and liquid at room temperature at semi-reasonable pressures. I'm not an expert on that sort of thing, though.
- Round trip efficiency: how much electricity comes out from electricity going in
- $/kWH capacity: lower is better, how does the battery cost scale as additional energy capacity is added?
- $/kW capacity: lower is better, how does the battery cost scale as additional power capacity is added?
- power to energy ratio: higher is better, to a certain point, but not usually at the expense of $/kWh capacity. If your ratio is 1:100, then you're in range of 4 days duration, which means at most 90 full discharges in a year, which highly limits the amounts of revenue possible.
- Leakage of energy per hour, when charged: does a charged battery hold for hours? Days? Weeks?
These all add up to the $/kWh delivered back to the grid, which determines the ultimate economic potential of the battery tech.
Lithium ion is doing really great on all of these, and is getting cheaper at a tremendous rate, so to compete a new tech has to already be beating it on at least one metric, and have the hope of keeping up as lithium ion advances.
At first, I thought this was an elaborate joke because fossil fuels are effectively "CO2 batteries."
Instead, it's compressed gas. Which is fine and possibly the best solution in certain contexts. But, it isn't exactly revolutionary or necessarily preferable to Li-ion most of the time.
Can somebody versed in thermodynamics explain me how can it work?
They say that they keep CO2 in liquid form at room temperature, then turn it into gas, and grab the energy so released.
* Isn't the gas be very cold on expansion from a high-pressure, room-temp liquid? It could grab some thermal energy from the environment, of course, even in winter, but isn't the efficiency going to depend on ambient temperature significantly?
- To turn the gas into the liquid, they need to compress it; this will produce large amounts of heat. It will need large radiators to dissipate (and lose), or some kind of storage to be reused when expanding the gas. What could that be?
- How can the whole thing have a 75% round-trip efficiency, if they use turbines that only have about 40% efficiency in thermal power plants? They must be using something else, not bound by the confines of the Carnot cycle. What might that be?
This is a fairly elegant idea. But it's definitely not "long term storage" as they claim it to be. A long-term storage solution that only holds energy for 8 hours is quite useless. Also, a long-term storage solution needs to be proportionally less expensive than a short term one in order to be equally profitable. For example, if you charge-discharge a lithium battery on a daily basis, and you use any long term solution to charge-discharge every 100 days, then the second needs to be 100 times cheaper if you want to get the same profit, because you sell the electricity only once vs 100 times for the battery. But this solution claims to be only slightly less expensive than lithium batteries, certainly not by a factor of 100. Not even by a factor of 2.
I'm guessing the diagram is missing a bit on the heat exchanger side; they're going to need to dump plenty of (environmental) heat into the expansion thingy to keep the liquid CO2 boiling off indefinitely at the pressure they want.
If this is intended for small-scale to medium-scale on-premise storage then the evaporating CO2 could also serve as the cold side of a building-size AC system for extra efficiency during the high demand portion of the duck curve.
I think there may be quite a market for maintaining hot and cold (and pressurized/liquified) sinks throughout the day/night cycle in highrises or entire cities.
This is potentially promising because it puts pressure on batteries, which gives us more options and reduces the dependence on specific minerals. Also may be cheap enough to be worth putting right next to a solar farm when batteries don't make sense.
What are the drawbacks of this battery compared to a Lithium-Ion battery? I would assume practicality (sizing, installation, etc...) but I would be interested to hear others thoughts on this. This site does a great job marketing the battery but not defining the drawbacks, hence why I am asking.
There are historical examples of entire villages around lakes suffocating during a limnic erruption.
I can't exactly find what sort of specs an installation of a large co2 battery might have, so it may be small beans relatively speaking, but that is still a lot of co2 in a very small area, and I certainly hope that both the engineers and regulators know what they're doing with it.
brilliant!, WOW!, how the fuck did everybody else miss this till now!
this could be easily cobbled together useing junkyard salvage!
zero exotic anything! -37°c, I've lived in colder places.
it will scale down to house or smaller sizes, or all the way up to primary grid power.
far north areas with abandoned mines into the permafrost will benifit from this.
very tickled by this
edit: there are a number of hazards and failure modes that are unique to this , but in no way as a dangerous as most other current power generation and handling of chemical storage and transport, and most of the danger to the public can be eliminated by sufficient set backs, ie:in a breach
the CO² would dissapate below lethal levels quickly.
tl;dr: it's a gas compression/decompression energy storage mechanism. It's nothing new and I have never seen one being being financially viable so far.
CO2 Battery
(energydome.com)144 points by xnx 21 hours ago | 125 comments
Comments
https://www.latitudemedia.com/news/form-energy-brings-in-mor...
The scale of investment required makes it quite hard for new companies to compete on cost:
https://www.theinformation.com/articles/battery-industry-sca...
A gas-based design seems like it would be better at a small scale - e.g. the facility in the link has a reservoir the better part of a mile away from the turbines, and has a max output of 600 MW or so.
CO2 may actually be a good working fluid for the purpose - cheap, non-toxic except for suffocation hazard, and liquid at room temperature at semi-reasonable pressures. I'm not an expert on that sort of thing, though.
- What's the energy areal and volumetric density kWh/m2 & kWh/m3 of this storage?
- How did they derive their CapEx savings figures?
- What's the peak charge/discharge rate of an installation?
- Can this storage be up/down-scaled in capacity and rate and by what limiting factors?
- Round trip efficiency: how much electricity comes out from electricity going in
- $/kWH capacity: lower is better, how does the battery cost scale as additional energy capacity is added?
- $/kW capacity: lower is better, how does the battery cost scale as additional power capacity is added?
- power to energy ratio: higher is better, to a certain point, but not usually at the expense of $/kWh capacity. If your ratio is 1:100, then you're in range of 4 days duration, which means at most 90 full discharges in a year, which highly limits the amounts of revenue possible.
- Leakage of energy per hour, when charged: does a charged battery hold for hours? Days? Weeks?
These all add up to the $/kWh delivered back to the grid, which determines the ultimate economic potential of the battery tech.
Lithium ion is doing really great on all of these, and is getting cheaper at a tremendous rate, so to compete a new tech has to already be beating it on at least one metric, and have the hope of keeping up as lithium ion advances.
One of the few numbers I could find on their site was:
> Our standard frame 200MWh battery requires about 5 he (12 acres) of land to be built.
They also refer to it as a "20MW/200MWh" plant.
Instead, it's compressed gas. Which is fine and possibly the best solution in certain contexts. But, it isn't exactly revolutionary or necessarily preferable to Li-ion most of the time.
They say that they keep CO2 in liquid form at room temperature, then turn it into gas, and grab the energy so released.
* Isn't the gas be very cold on expansion from a high-pressure, room-temp liquid? It could grab some thermal energy from the environment, of course, even in winter, but isn't the efficiency going to depend on ambient temperature significantly?
- To turn the gas into the liquid, they need to compress it; this will produce large amounts of heat. It will need large radiators to dissipate (and lose), or some kind of storage to be reused when expanding the gas. What could that be?
- How can the whole thing have a 75% round-trip efficiency, if they use turbines that only have about 40% efficiency in thermal power plants? They must be using something else, not bound by the confines of the Carnot cycle. What might that be?
I wonder if they design in flow channels for the heavier CO2 to flow down to safe, unpopulated areas.
Is there an advantage to the domes? IIRC some CAES system are put into old mines, that sort of thing.
If this is intended for small-scale to medium-scale on-premise storage then the evaporating CO2 could also serve as the cold side of a building-size AC system for extra efficiency during the high demand portion of the duck curve.
I think there may be quite a market for maintaining hot and cold (and pressurized/liquified) sinks throughout the day/night cycle in highrises or entire cities.
I can't exactly find what sort of specs an installation of a large co2 battery might have, so it may be small beans relatively speaking, but that is still a lot of co2 in a very small area, and I certainly hope that both the engineers and regulators know what they're doing with it.
https://en.wikipedia.org/wiki/Limnic_eruption