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Cake day: March 22nd, 2026

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  • I’m hopeful it will be good for aviation. It’s pretty hard to compete with kerosene’s 46.2 MJ/kg. The best batteries today are around 300 Wh/kg in commercial use, and some labs have hit 700+ Wh/kg. But with a MJ being equal to 278 Wh, we’re still talking 20-50x the energy density by weight. And that’s before even talking about how chemical fuels that are burned off leave less weight behind for the remaining vehicle, whereas a discharged battery weighs pretty much the same as a fully charged battery.

    Also, if we do move to storing energy in chemical bonds, pulling carbon out of the air, that basically turns into a carbon sequestration technique with whatever excess solar/wind energy we end up with, especially if we intentionally overbuild the capacity for non-peak production, and leave a method for using that energy during peak periods.





  • Yes, the specific accounting rules make the line between “profit” and “loss” fuzzy at times, but however you slice it, nuclear power costs a lot of resources for the amount of electricity that it produces. The money represents an opportunity cost of engineering effort and concrete and steel and equipment manufacturing and mining that could have been steered towards other types of projects.

    I’m agnostic towards the technology itself, but the economics of nuclear power just don’t make sense in the current environment, where we know that any new plants will get undercut by technologies that are already on the market today (solar+wind+batteries), technologies right around the corner (advanced geothermal), and even technologies that might be commercialized (fusion) within the 50-80 year lifespan of any new fission plant. That’s the competition, and I don’t think new nuclear plants are gonna be able to compete with those other technologies on cost.


  • Assuming theyre above with a cost of electricity of ~$0.20/kWh

    Can we assume that, after factoring in the actual portion that the accounting says goes to the power plant itself? The economics of utility scale electricity includes both generation and transmission, so you can’t just take that retail price and assume it all goes to the power plant that produced the electricity.

    Wholesale prices tend to stay below 10 cents in most parts of the country, although it sometimes spikes when grids are under strain. I think that’s probably a more fair assumption of how much the power plants themselves are paid for their production.


  • sparkyshocks@lemmy.ziptoScience Memes@mander.xyzNot a single one
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    5 days ago

    Public services (or even non-profit private organizations) still need to manage their resources efficiently. If the output of the service (number of meals fed to people, kilowatt hours produced, houses built, lives saved, passenger kilometers transported) is much smaller on a per dollar basis than comparable services, without good reason, then that organization is mismanaging resources.

    Plenty of public services can and do break even, or bring in more than they cost.

    Money is, in many ways, fake. But its accounting represents something real, in the real resources involved: land, human labor, physical materials like concrete and steel and copper that need to be turned into very complex equipment that require highly trained workers to operate and maintain.

    So when a project doesn’t break even, it’s worth asking whether the project is still worthwhile, whether the external benefits outweigh the localized costs. I don’t think modern nuclear passes that test (even if I believe that already-constructed nuclear should be extended as long as possible and operated at as close to full capacity as possible, because those up-front costs are already sunk).



  • There are a few different reasons why.

    • The US already built up its rail network around low speed trains. Those tracks aren’t suitable for high speed operations, and can’t be modified easily for high speed operations. It’s not just the tracks themselves, it’s the actual paths and bridges and road crossings. If a turn is too sharp, it can’t be taken at high speeds, and the actual curves in the path didn’t anticipate that one day trains would be fast enough to need more gradual turns. So any new rail would have to buy up the land rights with any new pathway, and that is going to be inherently expensive in the corridors dense enough to where there might be demand for passenger rail.
    • Rail crossings have to be designed for high speed rail, as well. There are safety and congestion concerns, so many high speed rail projects are required to build more grade separated crossings (bridges and tunnels), which significantly increases construction costs.
    • Rail has to compete with air travel and highway travel, in a country rich enough to have lots of people who can afford to fly, and where car-based highway systems are convenient and cheap. Basically, there’s a sweet spot of around 200-400 miles (300-600 km) between cities where it’s far enough that a car is inconvenient and close enough to where trains are competitive with buses or airplanes.
    • Along those lines, the US actually has pretty cheap intercity buses that use the existing highways.
    • Unfortunately, the city pairs that would have the highest intercity passenger demand also tend to pass through a lot of other cities. If you’re going from DC to New York, the most popular rail line in America, you’ll pass through Baltimore, Wilmington, Philadelphia, and Trenton, each with their own powerful politicians who would push to make sure the train actually stops for them. This is part of why the Acela, our fastest passenger train, takes 190 minutes to travel 226 miles between DC and New York, averaging only 70 mph (115 km/h) despite being capable of reaching top speeds of 160 mph (255 km/h).
    • Most rail in the United States is owned by freight/cargo train lines. The passenger network has to lease spots and is lower priority than freight. This leads to scheduling issues, including unscheduled delays.
    • Americans are just really bad at constructing big public works projects. Our dams, bridges, tall buildings, rail, highways, roads, power plants, and all sorts of other big projects are almost always behind schedule and over budget.
    • The less populated areas where it’s cheaper to acquire land rights also tend to be more environmentally pristine, which means there are environmental concerns around projects like these. In our political system, Republicans are much more likely to ignore those environmental concerns, but they use that political clout to build highways and oil pipelines, not passenger rail. Advocates for passenger rail tend to also be more environmentally conscious, so the environmental concerns do tend to slow down any proposed rail project.

    There is high speed rail called Brightline in Florida between Miami and Orlando, with the longest segment operating at 125 mph (200 km/h), and some of the more populous segments operating at 110 mph/180 km/h or 80 mph/130 km/h. It tries to manage those tradeoffs on all new track dedicated to it. But the company is struggling to make money.

    There’s a whole saga in California in that the proposed high speed rail project is decades behind and still bogged down, and has examples of all of these problems. The route it takes to connect the two largest cities on the coast (Los Angeles and San Francisco) goes through the inland central valley, to service a bunch of other cities in between. Bizarrely, phase 1 of the project will only serve the relatively low density, low population cities in the Central Valley, without connecting either San Francisco or Los Angeles. Some segments are to share rail usage with lower speed trains, complicating scheduling and risking delays. The environmental debates have slowed things down, as well.

    Watch what happens in Texas with its proposed high speed line (bogged down in political infighting), Florida (see above, already built and operational, but facing serious financial concerns about its ability to continue), and California (see above).

    I think we’ll eventually see some projects push through, especially if jet fuel gets more expensive than electrical grid power. But for now, America is uniquely hostile to passenger rail, and increasing high speed offerings isn’t necessarily going to induce enough demand for these projects to become economically competitive with other forms of intercity transportation.



  • That’s true of the metabolic pathways for fat, protein, and alcohol, too. Each oxygen molecule we breathe feeds into chemical reactions so that it picks up a carbon atom and becomes CO2 on the way out. The carbon comes from whatever food was metabolized, including anaerobic respiration where the lactic acid eventually gets cleared out.


  • Yes, but this published finding is interesting because it reduces the steps.

    Anyone can extract the elemental lithium from lithium cells, but it takes a lot of energy and harsh solvents and creates a lot of waste byproducts.

    But extracting lithium iron phosphate (LFP) salts is much less energy intensive, if those salts can be reused. This paper shows that LFP can be extracted and then reused as an ingredient in creating LMFP, a cathode material with higher performance characteristics.

    This is akin to using a technique to filter water instead of cracking it into hydrogen and oxygen and reconstituting the elements back as water.



  • The biggest US market SUVs are huge, yes, but the SUV market as a whole is skewed heavily towards small SUV “crossovers,” basically as a replacement for sedans that are disappearing (probably due to a complex set of fuel efficiency regulations that perversely incentivize making bigger vehicles to get away with less fuel efficiency).

    Our most popular models are the Toyota RAV4, Honda CR-V, Chevy Equinox, Tesla Model Y, and Chevy Trax. 4 out of the 5 are smaller and lighter than, say, a BMW X3, and the Model Y (which is also a somewhat popular model in Europe) is about the same size as the BMW. So if X3s and Model Ys are representative of the typical SUV in Europe, then the most popular American SUVs are smaller.

    Even driving up next to our most popular sedan, the Toyota Camry, shows that these crossover SUVs aren’t actually longer or even taller at the highest point, just tend to be taller in the back to have a rear tailgate instead of a separate trunk compartment.





  • that 20000-30000 premium over ICEs

    What currency are you using for this comparison? Definitely not USD.

    A Tesla Model 3 runs for about $40k. A Camry runs for about $35k. Or if we want to go down market a Nissan Leaf is about $30k and probably comparable to a $25k Sentra.

    Similar trim levels of vehicles offered as both EV and gasoline powered show minimal difference. Compare the Ford F-150 Lariat in both the gasoline ($75k) and the EV versions ($79k). Or the new Lexus ES, where the EV ($49k) is actually cheaper than the hybrid ($51k).

    And if you go into the used market, EVs are starting to hit that market in real numbers, too. Plenty of options for under $20,000, and a handful of options for under $10,000.

    Cars are expensive. EVs generally are close to that already expensive price.



  • It sounds like you have no idea the magnitudes involved, or the timelines. You’re talking about something that took place over a period of 400 million years and whose effects (the presence of oxygen in our atmosphere and our oceans) remain. There’s no chance that geoengineering would change the oxygen levels to anything we can’t handle, and if it starts to head down that direction we can easily handle it (just stop the processes that would sequester carbon).

    It’s like being worried that your air conditioning is going to freeze your pipes in the house, in the middle of summer.