A novel variation on compressed air energy storage that should directly help replace a coal power plant by:
converting carbon dioxide gas into a compressed liquid form and then converting that liquid back into a gas, powering a turbine to generate electricity, according to the Department of Energy. The gas will be stored in what officials call an “energy dome.”
From a linked article discussing the proof of concept installation:
The company says its technology has an energy storage density 10-20 times higher than other compressed air energy storage (CAES) solutions and two-thirds that of liquid air energy storage (LAES). However, Energy Dome points out that its solution does not require the cryogenic temperatures of LAES which can increase system complexity and competitiveness, it claims.
The DoE adds:
Through the use of compressed CO2, the system aims to improve efficiency compared to similar systems, as it produces less heat during the compression cycle and can be stored as a liquid. Energy Dome’s modular system also offers flexibility that can support a more resilient power grid.
Compressed air energy storage currently tops out with round trip efficiencies of 67-71% in complex setups.
https://www.sciencedirect.com/science/article/pii/S2666202723002045# Search: “Compared to other adiabatic systems”
https://en.wikipedia.org/wiki/Compressed-air_energy_storage#
This seems kind of inefficient, but I love all these large-scale energy storage attempts. And these people are a hell of a lot smarter than I am.
Inefficient compared to batteries? I found another article saying this company hopes that the energy dome will cost ⅔ the cost of a lithium-ion battery installation with the same energy capacity. https://www.popularmechanics.com/science/energy/a61572150/carbon-dioxide-energy-dome-plant/
Every approach is inefficient. Gotta pick your losses. You have to keep in mind scalability (how many parts can be bought at what volume at what price). In particular if you are not planning many years ahead.
Spent breakfast researching this:
- the plant would store 200 MWh
- given the 10-hour figure, one would assume it can feed up to 20 MW to the grid at any time
- they have already built a 4 MWh pilot plant in Italy
- the utility has also been building lithium-ion battery farms, so it stands to reason they see enough potential in this approach to continue pursuing it
- compressed CO2 storage has advantages over compressed air in that it can be stored indefinitely at ambient temperature and has a higher energy density in liquid form
- it has disadvantages in terms of plant safety
So they’re literally using gas compression as a storage medium for energy? That’s genius.
In case you are in this community but haven’t religiously read everything on Low Tech Mag.
https://solar.lowtechmagazine.com/2018/05/history-and-future-of-the-compressed-air-economy/
The battery meter is a hoot. The Game Boy Camera images are just weird.
It’s an efficiency thing, the images are tiny compared to full color - the whole site is made to use as few resources as possible.They operate it off solar power (hence the battery meter) and around an ethos of reversing a lot of modern web design bloat practices. I appreciate them demonstrating the kind of stuff they advocate for with their own site.
2bpp with lossless compression is an order of magnitude fatter than what DCT codecs like JPEG can achieve, if you’re okay with all your illustrations being kinda shite. Even just 16 colors with no dithering would probably compress better.
You’d have to take that up with them - they might be interested in alternatives that improve efficiency. I wonder if they like that it’s very visibly a deliberate choice to modify the images for size, or if they feel they’d be answering constant ‘why do your images look bad?’ questions with a reduced color pallet.
For anyone else who wants more info, I think these are cool discussions:
https://solar.lowtechmagazine.com/about/the-solar-website/#why_website https://lobste.rs/s/9v0ioj/how_build_low_tech_website
It definitely conveys that it looks bad on purpose. There’s utility in that signalling.
I would have expected Ohio to have pioneered anything involving energy domes, not Wisconsin
It looks like energy domes may be something for everybody
I for one can’t wait to see more energy domes
Is pumped-hydro inefficient or something? All the arguments about flooding land and surveying geography seem bizarre if the alternative includes a big impermeable structure. We’ve got those, for water. They’re called pools. They’re nontrivial because you have to contain pressure that desperately wants to leak out, but holding compressed air is surely harder. Water also doesn’t change temperature when you move it uphill.
Why is this better than two reservoirs with a pipeline between them?
The main reason is you can site it in a lot of places you can’t put pumped hydro.
… what, just anywhere flat? Pumped hydro should be feasible wherever there’s a hill.
If we’re building big weird structures, even that is optional. You can put one pool above-ground and another in-ground. Deep and tall presumably beat wide.
To actually do the volumes that make pumped hydro practical you need not just a hill but a space which can hold a truly huge volume of water.
Yeah pumped hydro needs lakes, not pools, as far as I know. They flood entire mountain valleys, using the surrounding mountains themselves as the storage structure, because they need so much space.
But a warehouse-sized balloon works?
Yes, because phase transitions involve absolutely huge amounts of energy.
Don’t get me wrong, I love me a good pumped hydro solution, but they do come with a couple of disadvantages:
a) as others pointed out, you need a somewhat steep gradient between two places. Preferably for a bit of distance so as to increase efficiency by putting more turbines in. Their need for a gradient limits their use in flat locations such as the entire US Midwest, for example.
b) comparatively expensive and longer construction process than other storage forms.
c) usually you have to build the upper reservoir. That’s an environmental harm. IMHO not that big if a concern, but it’s there.
d) if you don’t build out a reservoir, but use an existing lake, you risk contaminating it with algae / cyanobacteria and wreaking havoc on fish and other wildlife.
