this post was submitted on 16 Nov 2024
375 points (86.5% liked)

Science Memes

11047 readers
2916 users here now

Welcome to c/science_memes @ Mander.xyz!

A place for majestic STEMLORD peacocking, as well as memes about the realities of working in a lab.



Rules

  1. Don't throw mud. Behave like an intellectual and remember the human.
  2. Keep it rooted (on topic).
  3. No spam.
  4. Infographics welcome, get schooled.

This is a science community. We use the Dawkins definition of meme.



Research Committee

Other Mander Communities

Science and Research

Biology and Life Sciences

Physical Sciences

Humanities and Social Sciences

Practical and Applied Sciences

Memes

Miscellaneous

founded 2 years ago
MODERATORS
 
(page 2) 50 comments
sorted by: hot top controversial new old
[–] [email protected] 30 points 7 hours ago (1 children)

I always wonder where we would actually be at as a civilization if it weren't for fuckass lobbyists and money hoarding greedy assholes. This is a perfect example. If we'd learned from our mistakes and actually improved on nuclear energy there's no telling where we'd be at this point.

load more comments (1 replies)
[–] [email protected] 27 points 7 hours ago* (last edited 7 hours ago)

"Right in the heart of it is an itty bitty windmill and that just don't sit right with me" - That one cousin at Thanksgiving

[–] [email protected] -4 points 2 hours ago (2 children)

arent we out of uranium by 2040 anyway? op can have our "nucular" waste anytime. why even waste time on a resource that we cant use in 15 yrs from now? super stupid.

load more comments (2 replies)
[–] [email protected] -1 points 2 hours ago (3 children)

For huge countries as like the US: Maybe. You have enough space to also store the trash somewhere for thousands of years.

For small countries, like most of Europe, where the population density is way higher: hard pass.

load more comments (3 replies)
[–] [email protected] 5 points 9 hours ago (7 children)

Slow, expensive, riddeled with corruption, long ago surpassed by renewables. Why should we use it?

[–] [email protected] 53 points 8 hours ago (6 children)

only antimatter could provide more energy density, it's insanely powerful.

produces amounts of waste orders of magnitude lower than any other means of energy production

reliable when done well

it shouldn't be replaced with renewables, but work with them

[–] [email protected] 13 points 6 hours ago (2 children)

But it's not done well. Just look at the new built plants, which are way over budget and take way longer to build then expected. Like the two units in Georgia that went from estimated 14bn to finally 34bn $. In France who are really experienced with nuclear, they began building their latest plant in 2007 and it's still not operational, also it went from 3.3bn to 13.2bn €. Or look at the way Hinkley Point C in the UK is getting developed. What a shit show: from estimated 18bn£ to now 47bn£ and a day where it starts producing energy not in sight.

load more comments (2 replies)
[–] [email protected] 10 points 8 hours ago (3 children)

Yes, but energy density doesn't matter for most applications and the waste it produces is highly problematic.

[–] [email protected] 18 points 8 hours ago (6 children)

85% of used fuel rods can be recycled to new fuel rods. And there's military uses for depleted uranium too. So, essentially every bit of the waste can be recycled. Can't say the same for fossil fuels.

load more comments (6 replies)
[–] [email protected] 3 points 7 hours ago

the waste it produces is highly problematic.

It's a solved problem. https://www.youtube.com/watch?v=4aUODXeAM-k https://www.youtube.com/watch?v=lhHHbgIy9jU

[–] [email protected] 2 points 8 hours ago (1 children)

If something is Nuclear enough it can generate heat, its just the reactors make use of an actual reaction that nuclear waste can't do anymore. Yever watch the Martian, he has a generator that's fuel is lead covered beads of radioactive material, it doesn't generate as much as reactors but it's still a usable amount.

[–] [email protected] 3 points 7 hours ago* (last edited 7 hours ago)

If something is Nuclear enough it can generate heat

That's an extreme oversimplification. RTGs don't use nuclear waste. Spent reactor fuel still emits a large amount of gamma and neutron radiation, but not with enough intensity to be useful in a reactor. The amount of shielding required makes any kind of non-terrestrial application impossible.

The most common RTG fuel is plutonium (^238^Pu, usually as PuO~2~), which emits mostly alpha and beta particles, and can be used with minimal shielding. It can't be produced by reprocessing spent reactor fuel. In 2024, only Russia is manufacturing it. Polonium (^210^Po) is also an excellent fuel with a very high energy density, but it has a prohibitively short half-life of just over a hundred days. It also has to be manufactured and can't be extracted.

^90^Sr (strontium) can be extracted from nuclear fuel, and was used by early Soviet RTGs, but only terrestrially because the gamma emission requires heavy shielding. Strontium is also a very reactive alkaline metal. It isn't used as RTG fuel today.

[–] [email protected] 6 points 8 hours ago (1 children)

Right now we probably use more energy to produce antimatter than getting it back

load more comments (1 replies)
load more comments (3 replies)
[–] [email protected] 8 points 6 hours ago

Not sure I get what you mean by "slow".

And it's not entirely shocking that we have more of the power source we've been building and less of the one we stopped building.

[–] [email protected] 3 points 5 hours ago

You go on thinking renewables are ever going to replace fossil fuel while we charge full tilt to our doom

[–] [email protected] 16 points 8 hours ago (4 children)

Sometimes the sun doesn't shine, sometimes the wind doesn't blow. Renewables are great and cheap, but they aren't a complete solution without grid level storage that doesn't really exist yet.

[–] [email protected] 20 points 8 hours ago (2 children)

Solar with Battery grid storage is now cheaper than nuclear.

[–] [email protected] 11 points 8 hours ago (4 children)

If the demand goes up I have some doubt, also, mining for Lithium is far from being clean, and then batteries are becoming wastes, so I doubt you would replace nuclear power with this solution

I guess in some regions it could work, but you're still depending on the weather

[–] [email protected] 13 points 7 hours ago* (last edited 7 hours ago) (1 children)

You don't need lithium. That's just the story told to have an argument why renewables are allegedly bad for the environment.

Lithium is fine for handhelds or cars (everywhere where you need the maximum energy density). Grid level storage however doesn't care if the building houising the batteries weighs 15% more. On the contrary there are a lot of other battery materials better suited because lithium batteries also come with a lot of drawback (heat and quicker degradation being the main ones here).

PS: And the materials can also be recycled. Funnily there's always the pro-nuclear argument coming up then you can recycle waste to create new fuel rod (although it's never actually done), yet with battery tech the exact same argument is then ignored.

load more comments (1 replies)
[–] [email protected] 7 points 7 hours ago

They're currently bringing sodium batteries to market (as in "the first vendor is selling them right now"). They're bulky but fairly robust IIRC and they don't need lithium.

[–] [email protected] 1 points 6 hours ago (10 children)

you know that grid storage does not always mean "a huge battery", you can also just pump water in a higher basin oder push carts up a hill and release the potential energy when you need it...

load more comments (10 replies)
load more comments (1 replies)
[–] [email protected] 4 points 7 hours ago* (last edited 7 hours ago) (2 children)

Would love to see a source for that claim. How many 9's uptime do they target? 90%, 99%

[–] [email protected] 5 points 7 hours ago (1 children)

This is old news now! Here's a link from 5 years ago. https://www.forbes.com/sites/jeffmcmahon/2019/07/01/new-solar--battery-price-crushes-fossil-fuels-buries-nuclear/

This is from last year: https://www.lazard.com/research-insights/2023-levelized-cost-of-energyplus/

As to uptime, they have the same legal requirements as all utilities.

I was pro nuke until finding out solar plus grid battery was cheaper.

[–] [email protected] 2 points 6 hours ago (1 children)

Source (1)

Later this month the LA Board of Water and Power Commissioners is expected to approve a 25-year contract that will serve 7 percent of the city's electricity demand at 1.997¢/kwh for solar energy and 1.3¢ for power from batteries.

The project is 1 GW of solar, 500MW of storage. They don't specify storage capacity (MWh). The source provides two contradicting statements towards their ability to provide stable supply: (a)

"The solar is inherently variable, and the battery is able to take a portion of that solar from that facility, the portion that’s variable, which is usually the top tend of it, take all of that, strip that off and then store it into the battery, so the facility can provide a constant output to the grid"

And (b)

The Eland Project will not rid Los Angeles of natural gas, however. The city will still depend on gas and hydro to supply its overnight power.

Source (2) researches "Levelized cost of energy", a term they define as

Comparative LCOE analysis for various generation technologies on a $/MWh basis, including sensitivities for U.S. federal tax subsidies, fuel prices, carbon pricing and cost of capital

It looks at the cost of power generation. Nowhere does it state the cost of reaching 90% uptime with renewables + battery. Or 99% uptime with renewables + battery. The document doesn't mention uptime, at all. Only generation, independant of demand.

To the best of my understanding, these sources don't support the claim that renewables + battery storage are costeffective technologies for a balanced electric grid.

[–] [email protected] 1 points 3 hours ago

It looks at the cost of power generation

Yes.

But then you added the requirement of 90% uptime which is isn't how a grid works. For example a coal generator only has 85% uptime yet your power isn't out 4 hours a day every day.

Nuclear reactors are out of service every 18-24 months for refueling. Yet you don't lose power for days because the plant has typically two reactors and the grid is designed for those outages.

So the only issue is cost per megawatt. You need 2 reactors for nuclear to be reliable. That's part of the cost. You need extra bess to be reliable. That's part of the cost.

[–] [email protected] 4 points 7 hours ago* (last edited 3 hours ago) (1 children)

Uptime is calculated by kWh, I.E How many kilowatts of power you can produce for how many hours.

So it's flexible. If you have 4kw of battery, you can produce 1kw for 4hrs, or 2kw for 2hrs, 4kw for 1hr, etc.

Nuclear is steady state. If the reactor can generate 1gw, it can only generate 1gw, but for 24hrs.

So to match a 1gw nuclear plant, you need around 12gw of of storage, and ~~13gw~~ 2gw of production.

This has come up before. See this comment where I break down the most recent utility scale nuclear and solar deployments in the US. The comentor above is right, and that doesn't take into account huge strides in solar and battery tech we are currently making.

The 2 most recent reactors built in the US, the Vogtle reactors 3 and 4 in Georgia, took 14 years at 34 billion dollars. They produce 2.4GW of power together.

For comparison, a 1 GW solar/battery plant opened in nevada this year. It took 2 years from funding to finished construction, and cost 2 billion dollars.

So each 1.2GW reactor works out to be 17bil. Time to build still looks like 14 years, as both were started on the same time frame, and only one is fully online now, but we will give it a pass. You could argue it took 18 years, as that's when the first proposals for the plants were formally submitted, but I only took into account financing/build time, so let's sick with 14.

For 17bil in nuclear, you get 1.2GW production and 1.2GW "storage" for 24hrs.

So for 17bil in solar/battery, you get 4.8GW production, and 2.85gw storage for 4hrs. Having that huge storage in batteries is more flexible than nuclear, so you can provide that 2.85gw for 4 hr, or 1.425 for 8hrs, or 712MW for 16hrs. If we are kind to solar and say the sun is down for 12hrs out of every 24, that means the storage lines up with nuclear.

The solar also goes up much, much faster. I don't think a 7.5x larger solar array will take 7.5x longer to build, as it's mostly parallel action. I would expect maybe 6 years instead of 2.

So, worst case, instead of nuclear, for the same cost you can build solar+ battery farms that produces 4x the power, have the same steady baseline power as nuclear, that will take 1/2 as long to build.

[–] [email protected] 1 points 6 hours ago* (last edited 6 hours ago) (1 children)

Uptime is calculated by kWh, I.E How many kilowatts of power you can produce for how many hours.

That's stored energy. For example: a 5 MWh battery can provide 5 hours of power at 1MW. It can provide 2 hours of power, at 2.5MW. It can provide 1 hour of power, at 5MW.

The max amount of power a battery can deliver (MW), and the max amount of storage (MWh) are independant characteristics. The first is usually limited by cooling and transfo physics. The latter usually by the amount of lithium/zinc/redox of choice.

What uptime refers to is: how many hours a year, does supply match or outperform demand, compared to the number of hours a year.

So to match a 1gw nuclear plant, you need around 12gw of of storage, and 13gw of production.

This is incorrect. Under the assumption that nuclear plants are steady state, (which they aren't).

To match a 1GW nuclear plant, for one day, you need a fully charged 1GW battery, with a capacity of 24GWh.

Are you sure you understand the difference between W and Wh?

load more comments (1 replies)
[–] [email protected] 2 points 5 hours ago (1 children)

Let's be clear, the only reason grid-level storage for renewables "doesn't exist" is because of a lack of education about (and especially commitment to) simple, reliable, non-battery energy storage such as gravitational potential, like the ARES project. We've been using gravitational potential storage to power our mechanisms since Huygens invented the freaking pendulum clock. There is simply no excuse other than corruption for the fact that we don't just run a couple trains up a hill when we need to store massive amounts of solar energy.

[–] [email protected] 0 points 3 hours ago* (last edited 3 hours ago) (1 children)

There is simply no excuse other than corruption for the fact that we don't just run a couple trains up a hill when we need to store massive amounts of solar energy.

How about basic maths? I

Scale is a huge fucking issue. The little country of the Netherlands, where I happen to live, uses 2600 petajoule per day. So let's store 1 day of power, at 100% efficiency, using the tallest Alp (the Mont Blanc).

Let's round up to 5000 meters of elevation. We need to store 2.6e18 joules, and 1 joule is 100 grams going up 1 meter. So to power a tiny little country, we need to lift roughly 5e13 kilos up the Mont Blanc. To visualize, that's 1.7 billion 40ft shipping containers, or roughly 100 per inhabitant.

Using 555m blocks of granite, you'd need 166 million of them (9 for every person in the country). Assuming a 2% slope, you'd need to build a 250.000m long railway line. And if you lined all those blocks up, with no space in between, you'd need 3328 of those lines (which then couldn't move, because they fill the entire space between the summit and sea level).

And that's just 1 small country.

load more comments (1 replies)
[–] [email protected] 10 points 7 hours ago

https://www.theguardian.com/environment/2024/oct/24/power-grid-battery-capacity-growth

US power grid added battery equivalent of 20 nuclear reactors in past four years

[–] [email protected] 14 points 8 hours ago* (last edited 8 hours ago) (3 children)

Thats a chicken/egg peoblem. If enough renewables are build the storage follows. In a perfect world goverments would incentivice storage but in an imperfect one problems have to occure before somebody does something to solve them. Anyway, according to lazard renewables + storage are still cheaper than NPPs.

load more comments (3 replies)
[–] [email protected] 1 points 5 hours ago (1 children)

Hey now, someone who knows almost nothing is just asking questions here.

load more comments (1 replies)
[–] [email protected] 2 points 8 hours ago (3 children)
load more comments (3 replies)
load more comments (1 replies)
load more comments
view more: ‹ prev next ›