406

Entropy? Never heard of it. (lemmy.dbzer0.com)

submitted 5 days ago* (last edited 5 days ago) by hsr@lemmy.dbzer0.com to c/science_memes@mander.xyz

157 comments fedilink hide all child comments

you are viewing a single comment's thread
view the rest of the comments

[-] WoodScientist@sh.itjust.works 35 points 5 days ago

Who says you power that thing with fossil fuels? The real way to do that is via giant nuclear reactors or reactor complexes.

Fission power can be made cheaper per MW by just making the reactors bigger. Economies of scale, the square cube law and all that. The problem with doing this in the commercial power sector is that line losses kill you on distribution. There just aren't enough customers within a reasonable distance to make monster 10 GW or 100 GW reactors viable, regardless of how cheap they might make energy.

But DACC is one of the few applications this might not be a problem for. Just build your monster reactors right next door to your monster DACC plants.

[-] Kecessa@sh.itjust.works 42 points 5 days ago* (last edited 5 days ago)

But then the power generated by those reactors is better used to power things that burn fossil fuel in a less efficient way or to simply replace the fossil fuel powered electricity generators...

Quebec transports its electricity over more than a thousand kilometers, surely distance from nuclear reactors isn't an issue if you build the infrastructure around it.

[-] driving_crooner@lemmy.eco.br 15 points 5 days ago

Only when the last carbon based power plant is close, we can see if there's energy left to waste on that capture carbon machine.

[-] xthexder@l.sw0.com 7 points 4 days ago

I'm sure the AI datacenters would have a few GW to spare if we put the LLMs on pause.

[-] cynar@lemmy.world 16 points 5 days ago

There are 3 use cases I've seen.

Making fossil fuel power stations "clean".
CO2 recovery for long term storage.
CO2 for industrial use.

It's no good for the first, due to energy consumption. This is the main use I've seen it talked up for, as something that can be retrofitted to power plants.

It's poor for the second, since the result is a gas (hard to store long term). We would want it as a solid or liquid product, which this doesn't do.

The last has limited requirements. We only need so much CO2.

The only large scale use case I can see for this is as part of a carbon capture system. Capture and then react to solidify the carbon. However, plants are already extremely good at this, and can do it directly from atmospheric air, using sunlight.

[-] Arcka@midwest.social 1 points 3 days ago

It's poor for the second, since the result is a gas (hard to store long term). We would want it as a solid or liquid product, which this doesn't do.

Why wouldn't the device include or feed a compressor to liquidize the CO2? It takes just a little over 5 atm of pressure which is trivial.

[-] cynar@lemmy.world 1 points 3 days ago

You also need to sustain 5 atm, with no leaks for years. Where is it being stored, and who's paying for the maintenance? All it would take would be a bit of civil unrest, or corruption, and the work could be undone in mass.

[-] gandalf_der_12te@discuss.tchncs.de 1 points 4 days ago

The only DAC variant i could see working out is if it takes the CO2 from high-concentrated sources (such as portland cement factories) and transforms it into something practical, like liquid fuel or methane.

It could be leading to cheaper methane than from biological sources, because technological processes can have higher efficiency, and therefore lower prices.

[-] SpaceCowboy@lemmy.ca 14 points 5 days ago

Solar and Wind are cheaper than nuclear now. The main problem is it's not sunny and/or windy every day. A carbon capture system doesn't need to be running 24/7 though.

If we build way more wind/solar than we use then the excess can dumped into things like this.

Sorry but the economics of nuclear just doesn't work for everything.

[-] notsoshaihulud@lemmy.world 2 points 4 days ago* (last edited 4 days ago)

One of the interesting energy capture ideas I've seen with Solar and wind is based on kinetic potential energy in high-rise buildings. So you build a sort of heavy weight elevator that is elevated during windy and sunny hours and then it slowly gets released and gravity driven friction generating energy.

This coupled with solar windows and it's a pretty neat idea (not sure how viable though)

Edit: examples: https://spectrum.ieee.org/gravity-energy-storage-elevators-skyscrapers

[-] xthexder@l.sw0.com 6 points 4 days ago* (last edited 4 days ago)

This might work on the scale of a building to even out its own power usage throughout a day, but to make a difference on a city grid scale, you need an insane amount of height and/or weight.

Check out Pumped Water Energy Storage. It's the same concept but uses water as the weight. Doing the math on the Ludington Pumped Storage Power Plant's active capacity, it stores over 100 billion pounds of water.

[-] uniquethrowagay@feddit.org 6 points 5 days ago

Good luck building enough capacity in nuclear power to do that. Nuclear plants tend to be a lot more expensive and take a lot longer to build than anticipated.

[-] yunxiaoli@sh.itjust.works 3 points 5 days ago* (last edited 4 days ago)

Literally only in the US and Europe. Remove the profit motive and don't keep on inefficient construction companies and it's a quick process.

[-] Tlaloc_Temporal@lemmy.ca 4 points 4 days ago

There's no profit motive for large scale carbon capture anyway, so big CC plants and big nuclear plants would need the same political will.

[-] uniquethrowagay@feddit.org 1 points 4 days ago

Can you point out a nuclear project that was a quick process? How would removing the profit motive make it quicker?

[-] yunxiaoli@sh.itjust.works 1 points 4 days ago

Sure, China. You can build a nuclear power plant from dirt to operation in 6 months. Not 10 years plus infinite overages, 6 months.

If there's not a perverse profit motive at every stage and instead people are rewarded for getting the job done and getting the job done right, you end up with high quality fast engineering.