Energy

Energy Dome uses carbon dioxide as a grid-scale battery

Energy Dome uses carbon dioxid...
Italian company Energy Dome says its "carbon dioxide batteries" offer a fast-response, cheap, grid-scale energy storage alternative to lithium batteries
Italian company Energy Dome says its "carbon dioxide batteries" offer a fast-response, cheap, grid-scale energy storage alternative to lithium batteries
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Italian company Energy Dome says its "carbon dioxide batteries" offer a fast-response, cheap, grid-scale energy storage alternative to lithium batteries
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Italian company Energy Dome says its "carbon dioxide batteries" offer a fast-response, cheap, grid-scale energy storage alternative to lithium batteries
The technology can respond very quickly in certain configurations, making it a good alternative for load spike smoothing as well as longer term storage
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The technology can respond very quickly in certain configurations, making it a good alternative for load spike smoothing as well as longer term storage

Carbon dioxide may finally get its chance to become a solution in the climate crisis. Italy's Energy Dome says its CO2 batteries will store energy at less than half the cost of lithium "big batteries," while also being very responsive to load demand.

This is one of a number of solutions being put forward to replace or complement lithium "big battery" installations designed to soak up excess energy when the grid's not using it, and then feed it back in when it's required.

We're going to need insane amounts of energy storage in the coming decades; within 30 years, we need to replace all the world's current 2.045 terawatts (that's 2,045,000 megawatts) of coal-fired electricity generation with clean alternatives, while significantly expanding that capacity to keep up with skyrocketing demand as nearly everything else that runs on fossil fuels – cars, trucks, boats, planes, industrial processes, you name it – gets electrified as well.

There's more than enough clean, renewable energy available; it just doesn't get generated right when it's needed the way coal-fired power can. So until the unlikely goal of a global energy grid is realized, the world's appetite for cheap ways to store and release green electricity is going to ramp up like mad.

While carbon dioxide is one of the world's biggest problems right now, Energy Dome proposes to use it as a solution, taking advantage of a dramatic expansion that it undergoes when shifting between its liquid and gaseous states.

Here's the idea: you start out with a giant, flexible bladder full of CO2 gas stored in a big dome. As energy is fed into the system, electric turbines compress the gas into tighter and tighter volumes, much like a compressed air storage system. Heat from this compression is drawn off into a thermal energy storage system, and the gas is condensed into a liquid, which can be stored under pressure at ambient temperatures. That's the charge cycle.

When it's time to discharge, the liquid CO2 is evaporated with the assistance of the stored heat, and its expansion drives a second set of turbines, generating electricity and feeding it back to the grid from whence it came as the gas goes back into the bladder dome. (Incidentally, if you're looking for a band name, Bladderdome appears to be free and the URL is available for purchase.)

These domes can be run in a number of different sizes and configurations, but a target full-scale plant would make around 25 MW and store between 100-200 MWh of energy.

The technology can respond very quickly in certain configurations, making it a good alternative for load spike smoothing as well as longer term storage
The technology can respond very quickly in certain configurations, making it a good alternative for load spike smoothing as well as longer term storage

Importantly, these CO2 batteries can operate very quickly, absorbing and releasing energy nearly instantly in certain configurations. This means they'll be useful for smoothing out demand spikes – typically a lithium speciality – as well as for buffering between renewable generation and demand curves, and building multi-day reserve storage that can kick in to stabilize the grid when bad weather knocks generation on the head for a few days.

Round trip efficiency is over 75 percent, says the company, and while that does mean you're throwing some energy away, this sector will likely play out almost entirely based on economics. Here, the company tells Recharge News, it can offer a levelized cost of storage (LCOS) as low as US$50-60 per MWh within a few years, where lithium batteries are sitting between US$132-245/MWh.

Now, that's still not as cheap as the Iron-Air battery we wrote about earlier this week, but then that one relies on slower chemical processes, so it's better suited to longer-term, slower-response situations. Grids worldwide would probably do well to diversify their storage systems in the medium term, to see which ones work best to address the emerging challenges of totally renewable energy supply.

Energy Dome says it's building a pilot plant making 2.5 MWe and storing 4 MWh on the island of Sardinia, Italy. It's set to go live in 2022. Check out a less-than-riveting video below.

The CO2 Battery | EnergyDome

Source: Energy Dome via Recharge News

6 comments
6 comments
aki009
Neat idea. I hope it works. But the claim in the article about needing to displace all coal based power plants in 30 years is kind of silly considering that China is building new ones as fast as they can, and those aren't definitely scheduled to shut down any time soon.
Karmudjun
Another instance of thinking outside of the box. Yes, Carbon Dioxide in our atmosphere (and in our oceans) does need to be sequestered as the rise in temperature and the clear risk of CO2 toxicity increases for many non-plant based species with the total ppm of CO2 in our atmosphere.
If this sequestration can be put to good use as Loz explained in this article - if these proprietary spin-artists at EnergyDome can not only sequester the CO2 but use the liquification and gasification to store excess energy & release it back (at a 25% loss) to smooth out the electrical grids - I'm all for it.
I cannot control Saudi Arabia or Kuwait, I cannot control China or Nigeria - all I can do is applaud the outside of the box thinking - and can't wait to see the proof of concept installation!
jerryd
LFP batteries will do it at that price at 95% efficiency today.
Daveb
I am always looking for a band name, thank you for that
TechGazer
I'm not sure whether CO2 is the optimum gas for phase-change storage; that depends on a lot of variables. I expect the amount used is insignificant compared to the amount in the environment, so it wouldn't really be of value as a sequestration method. I think this is more of a marketing gimmick: "Look, our patented method can store energy _and_ sequester CO2. Fund us!!!"
Chris K
I don’t know enough about energy storage to say whether this particular idea is good. What I do know for certain is a world wide energy grid sounds like a horrible idea. God help us if that ever get implemented.