"This giant bubble on the island of Sardinia holds 2,000 tonnes of carbon dioxide. But the gas wasn’t captured from factory emissions, nor was it pulled from the air. It came from a gas supplier… “The facility compresses and expands CO2 daily in its closed system, turning a turbine that generates 200 megawatt-hours of electricity, or 20 MW over 10 hours.”
On the downside, Energy Dome’s facility takes up about twice as much land as a comparable capacity lithium-ion battery would. And the domes themselves, which are about the height of a sports stadium at their apex, and longer, might stand out on a landscape and draw some NIMBY pushback.
This is surprisingly good! I would have figured it would have taken far more than twice the land than a Lithium battery solution.
Please let this be viable.
The more renewable energy and storage, the better.
I run a consulting practice around flexibility. Been around the energy space for 15 years. Boy if I had a dollar for every time I’ve heard “grid scale [x] will soon be everywhere”
Eh, HRSG’s got real popular in the 90s and now most major plants have them. Its not a rapidly changing space, dont get me wrong. But new shit comes around every so often.
Sure wish they mentioned the effeciency.
Could be very high, even the waste heat from the compression could be used to achieve more compression and turbines get to above 90%, that all depends on the scales they’re building this at. 70% overall doesn’t seem unrealistic as an educated guess.
even the waste heat from the compression could be used to achieve more compression
No. Waste heat can by definition not be converted to mechanical work.
Otherwise, one could build a perpetuum mobile: Convert heat to mechanical work, use that work to generate heat, convert it to work again, and so on. You’d have a machine that generates energy out of nothing, and that’s not possible because of the law of energy conservation.
https://en.wikipedia.org/wiki/Recuperator
A recuperator is a counter-flow energy recovery heat exchanger that recovers waste heat in the supply
Sure wish they mentioned the effeciency.
Without it you should dismiss the whole article as worthless garbage
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It came from a gas supplier…
Where do you think supplier got it from?
Also: WHERE ARE THE ROUNDTRIP EFFICIENCY NUMBERS???
This CO2 is acting as a reusable fluid in a closed loop. The initial capture of the CO2 costs energy, but the battery keeps using the same CO2 over and over again. So the question of efficiency should be more about land usage and maintenance of the rest of the parts and the labor needed for each megawatt stored vs what other grid scale energy storage costs in materials and labor.
The rough reality is that batteries aren’t going to be up to the task of grid scale energy storage unless they have a couple huge breakthroughs. Something like this is a far less materially expensive way to store energy for later use.
Currently most grid scale energy storage is just pumping water up a hill and letting it back down through a generator. It is extremely limited in where it can be used and requires tremendous space to be effective.
Compressing gas generates heat, and a significant part of that heat will be lost. Heat dissipation is irreversible, and this lowers efficiency a lot.
BTW the same reason why in industry, pneumatic drives are universally replaced by electric motors: Their efficiency is too low.
The number of decommissioned but still usable batteries are growing fast though, and plenty of storage sites use old battery packs, both from cars and home energy storage and stuff like it
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We had these things called Gasometers in the UK for a long time. They expanded with the amount of gas stored in them, and they kept the pressure of the local gas supply up. A local gas reservoir, or “gas battery” if you like.
These bubbles are basically the same idea but at higher pressure.
It’s still near atmospheric pressure. Liquid CO2 expanding is powering the gas turbines.
Ah the bubble is the expansion volume. Not the storage volume… got it. I had it backwards.
So yes, very similar then.
I imagine that the bubble portion is light weight enough, one could put it on the roof of a data center, apartment building, strip mall, etc. That appears to be the piece that takes up the most space.
Another thought. I wonder if the bubble portion could be oriented vertically, maybe inside a simple enclosure to protect it from wind.
I was thinking about much larger scale bubbles in “unwanted” geological depressions such as old open pit mines or rock quarries. The depression in the ground might offer more protection allowing it to scale up higher in volume.
I wonder how resilient they are to big winds.
Also from the article:
If the worst happens and the dome is punctured, 2,000 tonnes of CO2 will enter the atmosphere. That’s equivalent to the emissions of about 15 round-trip flights between New York and London on a Boeing 777. “It’s negligible compared to the emissions of a coal plant,” Spadacini says. People will also need to stay back 70 meters or more until the air clears, he says.
The article also mentions that they can deflate it in around 10 hours
Sounds pretty good
