• 0 Posts
  • 16 Comments
Joined 1 year ago
cake
Cake day: July 5th, 2024

help-circle


  • Yes, of course, there is financing and everything else. I was getting a bit deeper:

    If you have to spend 100 joules building a power plant, it better give back more than 100 joules during its lifetime - otherwise it was never worth it to build. That isn’t strictly true, there are special purposes, but certainly as a grid-scale energy deployment you would need - at a bare minimum - for each plant to pay for itself in terms of energy investment.

    The dollars follow from that physical reality.

    The first hurdle for fusion to clear is that the reaction outputs more energy than it needs to sustained. This would be a great academic success, and not much more.

    The second hurdle is that it outputs enough energy such that it exceeds the sustainment energy even after accounting for capture losses (e.g. from neutrons, turbine efficiency, etc.) and production efficiencies (lasers need more energy input than they impart to the reaction chamber, magnets need cooling, etc.).

    The third hurdle is that over the lifetime of a plant, it produces enough excess energy to build itself and pay the embodied costs of all maintenance and operations work. If the reaction is technically energy positive, but you need to replace the containment vessel every 48 hours due to neutron embrittlement, then the plant better be productive enough to pay for refining all that extra steel.

    The fourth hurdle is then that it produces more excess energy per unit of invested energy than any other form of power generation - at which point we’d never build solar panels again.

    These final hurdles are in no way guaranteed to be cleared. Artificial fusion needs to be orders of magnitude denser than natural fusion (Stars) to make any sense… a fusion power plant the size of Earth’s moon, with the same power density as the Sun, could only power around 1 million US homes.



  • Economical energy production, sure, not any energy production. There is a reason we no longer burn wood to heat public baths.

    I realize the science marketing of fusion over the past 60 years has been ‘unlimited free energy’, but that isn’t quite accurate.

    Fusion (well, at least protium/deuterium) would be ‘unlimited’ in the sense that the fuel needed is essentially inexhaustible. Tens of thousands of years of worldwide energy demand in the top few inches of the ocean.

    However that ‘free’ part is the killer; fusion is very expensive per unit of energy output. For one, protium/deuterium fusion is incredibly ‘innefficient’, most of the energy is released as high-energy neutrons which generates radioactive waste, damages the containment vessel, and has a low conversion efficiency to electricity. More exotic forms of fusion ameliorate this downside to a degree, but require rarer fuels (hurting the ‘unlimited’ value proposition) and require more extreme conditions to sustain, further increasing the per-unit cost of energy.

    Think of it this way, a fusion plant has an embodied cost of the energy required to make all the stuff that comprises the plant, let’s call that C. It also has an operating cost, in both human effort and energy input, let’s call that O. Lastly it has a lifetime, let’s call that L. Finally, it has an average energy output, let’s call that E.

    For fusion to make economical sense, the following statement must be true:

    (E-O)*L - C > 0.

    In other words, it isn’t sufficient that the reaction returns more energy than it requires to sustainT, it must also return enough excess energy that it ‘pays’ for the humans to maintain the plant, maintanence for the plant, and the initial building of the plant (at a minimum). If the above statement exactly equals zero, then the plant doesn’t actually given any usable energy - it only pays for itself.

    This is hardly the most sophisticated analysis, I encourage you to look more into the economics of fusion if you are interested, but it gets to the heart of the matter. Fusion can be free, unlimited, and economically worthless all at the same time.


  • skibidi@lemmy.worldtoScience Memes@mander.xyzPhD ain't no MD
    link
    fedilink
    English
    arrow-up
    4
    ·
    6 months ago

    Completely correct. There is also a (much rather in the US) ScD degree - Doctor of science.

    In the US, it is often identical to a PhD. If your institution offers it, you just check a box at the end of your program on whether you want a PhD or ScD. In Europe, an ScD is a higher degree than a PhD and requires some extra work to obtain.




  • You clearly didn’t comprehend what I wrote. Educate yourself on this topic - not from forum arguments, but from TEA and policy papers.

    For one, I said ‘base load’ generation isn’t needed. Your thinking that is is means your thinking on the matter is 10 years out of date. If you insist base load is needed, then gas plants and carbon capture systems are far cheaper and faster to build.

    You don’t care, though, as you aren’t seriously involved in the policy and just want to live in a world where you are right 🤷.


  • Base load is an outdated concept. It is cheaper, by an order of magnitude, to install surplus generation capacity using renewables and build storage to cover periods of reduced production.

    Nuclear reactors actually make terrible ‘base load’ generation anyway, as large swings in output induce thermal cycling stress in their metal components AND the economics of these multi-billion dollar investments depend on running near max output at all times - otherwise the payback time from selling power will extend beyond the useful life of the plant.

    The policy wonks shilling for nuclear are not being honest. The economics for these plants are terrible, they are especially terrible if The Plan ™ is to use nuclear as a transition fuel to be replaced by renewables - as then they won’t even reach break even. To say nothing of the fact that a solar installation in the US takes 6 months, while there have been two reactors under construction in Georgia for a decade…

    50 years ago, nuclear was a great option. Today, it is too expensive, too slow to build, and simply unnecessary with existing storage technologies.

    If y’all were really worried about base load power, you’d be shilling for natural gas peaker plants + carbon capture which has much better economics.




  • No, not even close.

    I’ve used Unix systems for years at work, and have dual-booted windows with various flavors of Linux at home for just as long. When I just need something to work, particularly something new or after a stressful day at work, I just use windows.

    Why? Because it will just work. Maybe it won’t work precisely how I want it to, maybe it will send all my data to Bill’s push notifications, but it will run. In the rare case it doesn’t, a quick google will fix it.

    Compare that to Linux, where most things will work most of the time. And when they don’t, you get to hunt through GitHub issues off-the-clock like a peasant, wading through comments from people with entirely different configurations and ‘dunno it works for me’.

    Linux is for tinkerers, and for people who want a Unix shell and can’t afford a Mac, it has a long way to go to be more than that.