50 ms·

I suspect solar (including wind/biomass) + batteries is going to trounce fission reactors in the not terribly long term. If you think of finance in terms of lat

• DennisP 11y ago
  Gigawatt-scale nuclear reactors take a long time. Ycombinator is investing in factory-produced reactors that fit in a truck. There are quite a few other companies working on small factory-produced reactors. Solar with batteries is a lot more expensive than solar alone. Solar is doing well right now with natural gas backup, but a lot of us would like to avoid fossil entirely. Solar with nuclear backup might be a great combination, assuming demand correlates reasonably well with daylight hours.
  • JoeAltmaier 11y ago
    Confused: if you have nuclear, skip the solar and save money?
    • DennisP 11y ago
      Sure, if nuclear ends up cheaper per kWh than solar without backup.
    • TheOtherHobbes 11y ago
      Depends if nuclear includes decommissioning and clean-up costs. Do you really want lakes full of residual waste for the next few tens of millennia? The UK currently has no idea what to do with a lot of its waste. So it's simply left to rust and ferment in water - not a good outcome. Sustainable intermittency turns out to be something of a myth anyway. Intermittency effects across Europe turn out to be negligible. So instead of building nukes, you can spend the money on mixed-mode sustainables and a hugely improved distribution grid and get a cleaner and more reliable outcome overall. You can also make sustainables distributed, and run them on a domestic scale as well as an industrial one. PV roof installations have worked well in Germany and are starting to work well in the UK, even though neither location is known for being sunny. You'd get much better results in the sunnier parts of the US.
      • DennisP 11y ago
        Long-term waste isn't a factor for UPower or Helion.
        • sebastianconcpt 11y ago
          How?
          • DennisP 11y ago
            UPower is a fast reactor. 99% of nuclear waste, and almost all long-term waste, is transuranics, which fast reactors use as fuel. What remains is the fission products, which go back to the radioactivity of the original ore in a couple centuries. Encase them in glass and bury them, and you're good. Helion is a fusion reactor. Its "waste" is helium, and it uses a reaction that produces only 6% of its energy as neutron radiation. In both cases the reactor itself may become somewhat radioactive, but that's another short-term problem.
  • beat 11y ago
    So how small a reactor? And what sort of cost, what sort of setup time, what sort of safety constraints (ie, current reactors are generally water-cooled and need access to large bodies of water)? It's possible to trim the cost of reactors from the billions to the millions, maybe, but how many millions? Certainly, solar with batteries is a lot more expensive - but to my point, startup cost is low. Latency, or bandwidth? The long-term cost/kwh may be higher for solar, but the short-term startup expense will be much lower, unless you can get the factory-built reactors down into the thousands rather than millions of dollars. If nuclear is cheaper than solar in a decade or two, but costs ten times as much in the short run, there's a tremendous advantage to solar, battery cost or not. Opportunity cost matters tremendously.
    • DennisP 11y ago
      Startup cost for solar is not all that amazingly cheap per watt, and if you include batteries it's probably more than nuclear. UPower's design doesn't require a large body of water: http://spectrum.ieee.org/energywise/energy/nuclear/startup-designs-trucksize-nuclear-reactor http://spectrum.ieee.org/energywise/energy/nuclear/startup-d... For setup you deliver it with a truck and bury it. Other modular nuclear designs are a bit bigger but still in the range of small natural gas plants, which are competing quite well. If Helion works out then fission and solar will both be mostly obsolete. They'd be 50MW plants, retailing power at four cents per kWh, with no significant safety concerns.
      • smil 11y ago
        Wouldn't trust a Silicon Valley startup to care about our properly execute for "safety." This is a pump and dump, making a quick buck.
        • lutorm 11y ago
          You mean "release early, release often"?
          • jddw 11y ago
  • mrbabbage 11y ago
    > nuclear backup That wouldn't work with current nuclear reactors, whose startup / shutdown sequences take hours. Typically, the grid operator runs nuclear plants at nearly 100% 24/7 (so called "baseload") due to this. I'd be curious how truck-sized reactors work and whether or not you could operate them as load-followers rather than baseload. That would make them extremely attractive for replacing natural gas peakers, especially as more wind / solar get onto the grid.
    • DennisP 11y ago
      My point mainly is that if there's more demand when solar produces more energy, then you can pretty much run the nuclear plants all the time and get a decent balance. But I suspect the small reactors will be more flexible. Molten salt reactors are supposed to load-follow automatically with a lag of thirty seconds or so. (And of course with small fusion reactors it wouldn't be a problem at all.)
      • nosuchthing 11y ago
        Solar generation is less predictable, and the grid needs an energy source that is capable of quickly adjusting to the current fluctuation in demand of consumers.
        • beat 11y ago
          That's where the batteries come in. To continue the software metaphors, batteries provide caching, and the cache is tunable for cost and performance. This wasn't viable a decade ago, but with the advances in solar/wind cost/performance, and the advances in battery cost/performance, it's really becoming a powerful option.
          • deleted 11y ago
            [deleted]
      • jddw 11y ago
        You're right. It is also a common misconception that nuclear reactors cannot load follow, they can: http://ansnuclearcafe.org/2013/02/14/responding-to-system-demand/ http://ansnuclearcafe.org/2013/02/14/responding-to-system-de... One of the main limitations is the stress it puts on the fuel. Many advanced reactors overcome these limits, and if financially incentivized, they will definitely load follow. On top of that, the UPower reactor has a thermal transport time constant nearly 10 times that of other reactors, and its fuel is immune to the shocks that bother LWRs. In fact, the same type of fuel was used in a research reactor and would be ramped in power from 5 watts to 150 billion watts in less than 50 millionths of a second. That puts a lot of stress on fuel, yet this fuel kept its stride without breaking a sweat. This reactor is built like a tank, and is designed to be quite resilient and flexible. It can definitely load follow to support a renewable heavy grid system. In fact it's been considered for use as a grid stabilizer at substations because of these abilities.
• rndmind 11y ago
  Solar is indirectly fusion power.
  • deleted 11y ago
    [deleted]
  • SeoxyS 11y ago
    So are fossil fuels, and pretty much everything else on earth, including life itself. Carbon-based fossil fuels are simply very old plants which have stored and concentrated solar energy. The only non-solar non-fusion energy I can think of is that which comes from the earth's core, geothermic. And even that is believed to be powered by nuclear fission.
• jfoutz 11y ago
  Rather than batteries, i think pumping water up a hill will be a lot cheaper. use the water to drive a generator. massive daily over production to fill the nightly (or much longer) reserve.
  • taf2 11y ago
    I like this idea a lot the only downside is it expands the land area and possibly increases complexity - but I think for major power planets it's a great option just not for the home installations.
  • gumby 11y ago
    That is the state of the art for energy storage today and basically all the sites are taken. Sure, if energy costs go up a LOT a few more will become viable, but if you look around, for example, Californa, it's hard to find another viable site.
    • jfoutz 11y ago
      I'd bet you know far more about it than i do. Assuming solar gets super super cheap, well, then we can do a lot. like suffer the losses of long distance transmission lines. Arizona supplying California might be feasible if the solar panels are cheap enough. Parent poster seems to be implying a few bucks a panel, rather than thousands or even hundreds of dollars.
      • xyzzyz 11y ago
        >Arizona supplying California might be feasible if the solar panels are cheap enough. For 1000 kV AC transmission line from Arizona to California, transmission losses should certainly be smaller than 5%, even less for DC. Arizona is pretty close to California when it comes to electricity transmission.
    • dredmorbius 11y ago
      Seawater lower basin adds considerably to site count. There are other concerns: elevated highly variable salt water ponds and wetlands, and general nastiness of saltwater engineering: corrosion and marine life growth especially. But generally, pumped hydro is really hard to beat.
• gordon_freeman 11y ago
  The similar thing I have heard Elon Musk saying in some interview that it's just a myth that people have to think we will never able to generate enough energy out of solar-panels compared to the nuclear reactors. He said that the amount of land one needs to build a massive nuclear plant and then other things to maintain it and considering the 10-50 miles area enveloped to plant where it is dangerous to live. If you use the same amount of land to place solar-panels then the energy produced by solar will overtake that of from nuclear plants.
  • jddw 11y ago
    This is completely false. First it is not dangerous to live in those zones, second this is a pretty accurate land comparison - http://www.thingsworsethannuclearpower.com/2012/03/using-too-much-land-to-produce-energy.html http://www.thingsworsethannuclearpower.com/2012/03/using-too.... Maybe Elon should visit a nuclear plant...
    • spacefight 11y ago
      Maybe we can argue that "not dangerous" is simply not true? Chernobyl, Fukushima and many other "smaller" accidents happened.
• flgb 11y ago
  I suspect they will continue to trounce fission and fusion for a long time, at least until there is some some technical innovation in transmission and distribution. Transmission and distributed generation accounts for half the cost of electricity. The question for our electricity future is distributed versus centralized generation, and distributed will probably win.
  • jddw 11y ago
    So distribute fission and fusion, overcomes much of that. And distributed solar and wind needs backup which is usually fairly centralized. Unless you want to spend 3-5 times as much for your energy to buy batteries.
    • pjc50 11y ago
      Fusion needs to be distributed well away from population centres. Until we've had enough contained failures of the "intrinsically safe" reactors to be convinced that it's actually true.
• ytdht 11y ago
  where is nuclear in your theory?
  • beat 11y ago
    In my theory, nuclear is mostly irrelevant. It's not a model for the third world (who can't afford or operate reactors, even if the rich nations would let them have one), it's not a model for low population densities, and it generally costs in the billions and requires the involvement of both local government and international regulatory agencies. Sure, UPower and others are working on reactors that are small scale, cheaper, safe, and hard to weaponize. But they're still a limited solution to the problems I'm bringing up. Fusion is a fantasy. Maybe someday it will be real, but betting the world on it is foolish. Solar is cheap, fine-grained, clean, sustainable, and not weaponizable. It solves all my core problems. Why should I care about difficult, expensive, dangerous nuclear?
• icanhackit 11y ago
  think of finance in terms of latency/bandwidth [...] reactors are high latency - they're expensive and take a long time to set up I like this metaphor. I think what you might have implied but didn't explicitly mention was distributed vs centralized when thinking about these systems as well. Solar can be a distributed system whereas fission & fusion systems are centralized. Even though you can make small fission systems and IIRC Skunkworks is working on a small fusion reactor (small = fits on freight truck...once the damn thing works) you still have issues with waste, heat, faults etc. so they need to remain isolated from living space. Thus they are better utilized in a centralized manner. Sticking with the computer/internet metaphors, you could consider solar to be like a Solid State Drive while fission is very much the classic HDD, moving parts and all. The elimination of moving parts/complexity to generate electricity makes solar suitable for the home just as NAND is better for portable devices like phones. Pros: speed vs capacity, Cons: cost vs complexity - pick one from each pile.
  • XorNot 11y ago
    Faults are not a serious issue with a fusion reactor beyond it breaking down. Neither is waste - an inert reactor is harmless unless you insist on crowbaring into the core to bathe in all those activated inner wall materials.
  • jddw 11y ago
    Interesting analogy and choice of words since UPower is building a solid state reactor.
    • icanhackit 11y ago
      From what I can gather it's solid state in the sense that it's a passive system that doesn't require pumps but it still involves heat creating steam which in turn drives generators. The liquid changes phase from liquid to gas then cools to a liquid again, so it can remain self-contained. Very cool, but feels kinda not as solid if you know what I mean. Don't want to downplay how neat it is though.
  • XorNot 11y ago
    Faults are not a serious issue with a fusion reactor beyond it breaking down. Neither is waste - an inert reactor is harmless unless you insist on crowbaring into the core to bathe in all those activated inner wall materials.
• ageofwant 11y ago
  While I believe/hope you are right there are use cases for gigawatt energy sources that cannot be met even with pervasive PV deployments. We will not be manufacturing aluminium with solar. We won't be pumping gigga tones of C02 out of the atmosphere and seawater with solar. We won't convert the Ort cloud to habitats with solar. For that we need fusion or fission. No way around it.
  • rwallace 11y ago
    Actually, aluminum manufacturing is a perfect use case for solar, because it doesn't mind intermittency. (Or put another way, manufacturing energy intensive stuff is a perfect way to provide the storage that solar needs.)
• donttrustatoms 11y ago
  Solar is much cheaper and wind was already cheap, however the question, for both carbon and cost, is what is the price of the renewable intermittents with storage and backup. Batteries and storage in general have not had the step changes in cost and performance that solar has. Backup tends to be fossil plants. Ultimately energy density is a zero sum game for the environment and cost. In more detail: On storage: Rough calculations show, if there were just enough Powerwalls to backup US peak demand for one hour it would require 10x the global annual mining production of lithium. And that's just one hour. And that doesn't include the electricity production. On panel material required for production: It's generally estimated that US power, with good transmission, would require enough solar panels to cover the entire state of Massachusetts. Most non solar advocates think it's this square footage that's important. But of course this can largely be put on built land or in deserts so that is a relatively moot point. In fact, I want to get solar panels on my roof. However the real concern is what does this look like in terms of material mining? In immense panel production factories? (which isn't the greenest mfg process ever, likely one of the reasons it is largely done in China) On mining and transporting material required: Mining is almost entirely powered by fossils, it has to be. And so is most transport. And so is recycling of metals. So the energy density of an energy source really is a zero sum game. If it takes a millionth the material for one source versus the other, that adds up. On maintenance Then in maintenance, solar farms are truly "farms"- they require a lot of water to wash away dust to operate optimally. A states' worth of water is significant. On lifetime/end of life First of all the lifetime of a panel is very optimistically 30 years/for a nuclear plant 60-80 years, and for the UPower fuel in particular can be used and recycled repeatedly for about 70+ years. afterlife/recycling Then in recycling at end of life, and this is why I got so excited about nuclear as a somewhat hippie child growing up around oil companies in Oklahoma, solar is going to require a lot of energy (and fossil fuels or nuclear) to recycle, while nuclear can produce energy in recycling its fuel. The main import, to me, is: what is the energy density of this energy, and if emitting, how much pollution? Coal is far more energy dense than wind, which is why humans evolved from windmills and wood to coal. But it's so polluting which is why we are all working towards better sources, and the greater energy density (nuclear on order of 2M x any other source) that's roughly 2M less trucks transporting, 2M less mining to do, 2M less recycling, etc. Thats more on the environment than pure cost like you are saying but the costs add up if the full life cycle is taken into account on both sides.