5 ms·

Cool. But even if you have a working stellarator that's a very long way from an economically viable energy source. You've still got to a) figure out how to che

• tomxor 2y ago
  I don't think the point of this project is to be closer to economic viability, but to demonstrate an approach that would lead to faster economic viability due to allowing faster iteration and evaluation of small scale experimental designs. In HN terms they are demonstrating a significantly faster REPL by keeping the project small and minimising use of esoteric or highly bespoke components. It's the closest you can get to building your own stellarator by walking into radioshack. I think it's a pretty cool idea.
  • rgmerk 2y ago
    Yep, sure. And that's great.
• dexwiz 2y ago
  Newer solar panels don’t need full sun to function. It’s economically viable to place them further north and in cloudier climates now. So the area where these are alternatives are viable may be shrinking faster than you would expect.
  • rgmerk 2y ago
    Indeed, though in colder climates you do have the problem that peak electricity demand is precisely when you get minimum solar production. But in sunnier, warmer parts of the world (which notably includes India, Pakistan, Bangladesh, Indonesia, Nigeria, Egypt, Ethiopia, Iran, Mexico, and Brazil, amongst others), over the next few decades it's hard to see anything much competing against solar and batteries for the bulk of energy usage.
    • bkor 2y ago
      > But in sunnier, warmer parts of the world Though solar panels prefer if it isn't too hot. Still, any such inefficiencies are easily outweighed by their low cost. In Netherlands it is common to install practice (and advised) more Wp than the inverter can handle. Maybe also a solution if it gets too hot, make it up by having more panels.
    • thehappypm 2y ago
      That isn’t true yet, because most cold places don’t use electricity for heating; in Boston for example the norm is oil or gas furnaces. Europe typically uses gas for heating, as we all learned during the Ukraine war’s beginning. When I lived in the Boston area, our electricity use, peaked in the summer during air-conditioning season. That is, until we got a heat pump, then our electricity spiked like crazy in the winter. but we are long way from having the majority of homeowners using heat pumps for their primary heat source. (Also heat pumps are kinda awful compared to furnaces in my experience so we might never get there).
      • smolder 2y ago
        >heat pumps are kinda awful Heat pumps work great under the right circumstances. In cold climates like Boston and north of it, ideally you want ground source, which means digging deep (or wide) holes to flow water through instead of just pulling heat from outside air. Alternatively, (or additionally, ideally) they're best used in homes with very tight air envelopes, good insulation, and heat/energy recovery ventilation (HRV/ERV) systems. Installed in radiant heating systems in well-built houses, heat pumps are fantastic and you'll be comfortable all year for pennies on the dollar. The reality is that most (US) construction, especially older, is just terrible in terms of air seal and insulation. Couple that with a potentially undersized air-source heat pump, which gets inefficient as the outside temp gets near the low end of its operating range, and you will not have a great time. But even then they are a good way to supplement gas heating, so you can limit furnace use to the coldest weeks of the year and do the environment a favor, as well as cool in the summer.
        • thehappypm 2y ago
  • cm2187 2y ago
    Well as long as you have vast amount of storage capacity + overprovision, or an alternative source of on-demand electricity, the cost of which I never see included when comparing to on-demand energy sources like nuclear of fossil fuels.
    • eric-hu 2y ago
      I believe nuclear isn’t an on demand energy source. It’s great for base load, but it doesn’t scale up or down quickly.
      • bkor 2y ago
        > but it doesn’t scale up or down quickly. The newer ones can. Though that's partly my dislike. There's always yet another new technological solution for the various drawbacks. Which often are unproven (e.g. SMRs) and that often results in crazy cost overruns. Nuclear has a crazy high fixed cost so ideally you still run it continuously.
      • cm2187 2y ago
        That was true in the 70s. I think anything built in europe since the 80s can do load following and France does that every day. I think by regulation new plants must be able to adapt their production by something like 5% per 10min (or something of that order of magnitude), well within the range you need to meet intra day variations. Now whether it is optimal economically is another question. If you have some sources of energy in your grid that cost per usage (eg fossil fuels), you should rather switch those off than nuclear which costs the same whether you use it or not. But if your grid is almost all nuclear (eg France), you do load following.
        • eric-hu 2y ago
          That’s news to me. How do these newer reactors do it? I thought nuclear reactors are slow to ramp up. Are they over producing thermal energy relative to the plants electricity output?
          • 2y ago
  • Tor3 2y ago
    As someone living north of the arctic circle.. there are other issues than just clouds.
  • northerngnomel 2y ago
    As someone living in the further north, the issue of sun not going above the horizon for months at a time makes them a non-starter without 100% coverage from other sources, making them rather expensive without externalizing the costs to someone else
    • rgmerk 2y ago
      Sure. But, globally, you're the exception, not the rule.
      • northerngnomel 2y ago
        I was commenting on the parent >It’s economically viable to place them further north and in cloudier climates now Which it really isn't unless we're neglecting to count in the need for long-term backup power. There still exists some amount of solar even now, though government subsidies and government provided peaker plants may have something to do with it
        • bkor 2y ago
          > Which it really isn't unless we're neglecting to count in the need for long-term backup power. But that's not what the topic, no? It was about economically viable. It wasn't about fully relying on them. If someone can buy or place a solar panels/plant and it is economically feasible, then it is. E.g. EU is finally connecting the various electrical grids together. So that electricity can more easily be exported/imported. Yet another way to deal with the fluctuations.
          • luckylion 2y ago
            > If someone can buy or place a solar panels/plant and it is economically feasible, then it is. "then it is" what? economically viable? He still needs 100% backup from other sources, so you have to factor that cost in. Possible? Yeah, it's possible, but that wasn't the question.
• deleted 2y ago
  [deleted]
• fragmede 2y ago
  Not sure why steam engine is written like it's some crazy reveal. It's the accepted way of doing it in most other fossile fuel plants, to the point that there's a saying for it - someone, somewhere X is boiling water so you can boil water. There are other designs that have been proposed, but I'm not aware of anything in production that takes heat and turn it into electricity at powerplant scale. Eg RTGs exist, but only if you need a computer power supply's worth of power for decades.
  • ZeroGravitas 2y ago
    Perhaps because the steam part alone, even if powered by pixie dust and magic, can't compete on price with solar, and probably solar and batteries either (varies with latitude and time but the cost is going down and the latitude is getting wider). I think OpenAI is investing into a fusion design that avoids steam for exactly this reason, so it's not just an anti-nuclear talking point.
• slightwinder 2y ago
  > In sunny places (and I fully acknowledge that's not all of the world) it's still going to be hard to beat sticking bits of special glass out in a field and connecting wires to it. Why not both? Can't we utilize the special glass to fetch energy from a man-made fusion reactor, in similar ways as we use it to fetch energy from the natural fusion reactor in space?
  • pyrale 2y ago
    Treating this as a serious question: because the big reactor in the sky has a built-in gravity well and a very big sphere of vacuum that works as a free containment system while still letting just enough energy out to be useful. Also we don’t need to refill it or handle the spent fuel.
  • nine_k 2y ago
    No. D + T or D + D fusion reaction produces neutrons and hard gamma radiation. The special glass cannot capture the energy of these directly. The natural fusion reactor has a blanket that is literally thousands of kilometers thick. It effectively converts much of this into longer-wavelength electromagnetic radiation, from ultraviolet to infrared, with quite some visible light. That's what the special glass can make use of. Also, the highly radioactive blanket is kept hundreds of millions km away from consumers, which helps alleviate the problem of disposing of radioactive waste. With a planet-based fusion reactor, we'd have to think where to put thousands and thousands of tons of slightly radioactive concrete which would realistically serve as a blanket.
  • thehappypm 2y ago
    In theory, yes. Those are called radiovoltaics and are being researched.
• lupusreal 2y ago
  Steam turbines are very good at what they do, so I don't think that's the problem. Turbines are well understood technology so they're they're the major impediment to economic viability then everything else must be working amazing. I do think economic viability will be a major problem though. The fusion hype crowd focus on Q>1 being their major milestone but that's still a long way away from it being profitable to operate a fusion plant.
  • nine_k 2y ago
    IIRC, a cascade of turbines, going from high-temperature water steam to basically room-temperature ammonia, can reach a total efficiency exceeding 50%. Of course, ammonia is chemically active, and water at 700K is also chemically active, so the turbines, as usual, require special metallurgy and regular maintenance.
    • rgmerk 2y ago
      Sure, but your cascade of turbines isn't free. The capital cost of just the turbines is enough to make it hard to compete with solar and batteries in many situations.
  • rgmerk 2y ago
    Turbines are indeed very well understood and mature technology, and even where the fuel is almost free and the reactor (a coal burner) is cheap, steam turbines are too expensive to compete with solar electricity in most places now.
• johnea 2y ago
  That's all just good money after bad. How many more trillion $$$ are going to be pissed away on this? I'd say, shelve the idea for 50 to 75 years and then look at it again. In the mean time, I think we could make major headway on a global elecrtic grid, that connects whatever part of the planet is sunny with all the rest. Add to this some major storage capacity, and I think we could resolve almost all of our energy problems with the money that would be wasted on further fusion efforts.