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What you have to look at is the build price differences, not the overall cost. Cars are a perfect example. Sure a rare metal based fuel cell is only a small fraction of the cost of the total vehicle, but in the same way a combustion engine is also only a fraction of the cost of a conventional vehicle. If the engineering, research, and manufacturing that go into things like the the body and drive train cost $20k per car, that $20k will be the same regardless if its gasoline or hydrogen run. If the price of the ecological version is $5k more than the gasoline one then the consumers will still prefer the carbon emmisions. Now if easy availability to platinum or another great catalyst drop that difference to only $2k the consumer is more likely to use the clean car. Just think of how many people drive Prius's and they're far more expensive.
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Jan 15, 2016 21:05
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M_Gargantua posted:What you have to look at is the build price differences, not the overall cost. Uh, when was the last time you checked Prius prices? They start $24,000 which is rather low end for a car these days, and a midrange model costs about $32,000. For comparison, a Camry starts at $23,000 and a midrange model is $33,000; Ford Fusion starts at $22,000 and a moderately optioned up model will go for $32,000. About the cheapest car you can get these days are a few cars that go for around $15,000 in absolute base models. Something like the low end Chevy Cruze.
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Jan 15, 2016 23:45
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whats the minimum viable entry point for a generation co-op? like whats the smallest solar or wind farm you can build that you can just straight sell into a grid?
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Jan 16, 2016 01:02
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StabbinHobo posted:whats the minimum viable entry point for a generation co-op? like whats the smallest solar or wind farm you can build that you can just straight sell into a grid? Probably depends highly on the interest rate on your loans.
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Jan 16, 2016 01:39
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StabbinHobo posted:whats the minimum viable entry point for a generation co-op? like whats the smallest solar or wind farm you can build that you can just straight sell into a grid? That's going to be highly variable depending on where you are. If you're in the US and your state allows it, the lowest entry-point is going to be a community solar farm, also known as a solar garden, where a solar co-op runs a generation facility normally between 100kW to 2MW AC-watt solar power plant and shares are sold to a local community. Not many states allow this yet and it varies how the compensation for shares are handled between states. Above that community solar farm size, regardless of state, in the 2-10 MW range you're going to be forced to deal as a power plant selling at market rate. Whether that is actually viable and profitable is another matter, but that should give a scale for where you're forced to just sell to the grid instead of doing a net metering setup.
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Jan 17, 2016 10:25
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StabbinHobo posted:whats the minimum viable entry point for a generation co-op? like whats the smallest solar or wind farm you can build that you can just straight sell into a grid? Depending on your state ... you might be better off as a bunch of individuals, each 'running the meter backward.'
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Jan 25, 2016 20:45
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blowfish posted:Saw it into bits, drop bits on empty desert, pick slightly ablated bits out of craters? Blow the asteroidal metal into a foam lighter than water, shape it as a re-entry vehicle (like an Apollo capsule), de-orbit it into the ocean (attached thrusters needed), tow it (or the fragments) into port. Think of pumice, which is a rock that floats. Assuming there is enough residual hydrogen/water vapor in the asteroid to provide the blowing gasses. As it ablates on re-entry the iron vapour will help fertilize the oceanic plankton, eating more of that pesky CO2. Some of those metallic asteroids are largely nickel-iron, which is rough-and-ready stainless steel. Add some chromium and you got spec 304 SS. No smelting required -just the melt in the furnace. ... I bet Mr. Musk has already put some thought to this, I plumb reckon. zimboe fucked around with this message at 15:24 on Jan 28, 2016 |
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Jan 28, 2016 15:04
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blowfish posted:~natural~ ~earth~ gold, the new trend for rich hipsters The word you're looking for is purestrain gold.
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Jan 28, 2016 23:58
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News from Wendelstein 7-X: Nuclear fusion device's 1st test with hydrogen declared a success quote:The resulting super-hot gas, known as plasma, lasted just a fraction of a second before cooling down again, long enough for scientists to confidently declare the start of their experiment a success.
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Feb 4, 2016 10:15
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zimboe posted:Blow the asteroidal metal into a foam lighter than water, shape it as a re-entry vehicle (like an Apollo capsule), de-orbit it into the ocean (attached thrusters needed), tow it (or the fragments) into port. This would probably be a good idea in a fantasy world where it was actually possible and also steel wasn't literally worth less than dirt.
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Feb 4, 2016 12:54
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silence_kit posted:A lot of people who write hysterical articles about the scarcity of materials used in microelectronics do not understand this. The amount is really small. Solar cells are slightly different because they necessarily must be large area devices and not tiny chips because unconcentrated sunlight isn't very energy dense, but still the amount of material used is not that much.
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Feb 4, 2016 14:08
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ANIME AKBAR posted:I never understood why you can't just use a big fresnel lens to concentrate light onto smaller photocells. Is it not done because the lenses are more expensive than photocells per unit area? You can do this. https://en.wikipedia.org/wiki/Concentrator_photovoltaics There are tradeoffs.
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Feb 4, 2016 14:50
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zimboe posted:Blow the asteroidal metal into a foam lighter than water, shape it as a re-entry vehicle (like an Apollo capsule), de-orbit it into the ocean (attached thrusters needed), tow it (or the fragments) into port. If you reduce the asteroid's density below that of water, I don't know how it would survive atmospheric entry without disintegration.
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Feb 4, 2016 14:54
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Pander posted:If you reduce the asteroid's density below that of water, I don't know how it would survive atmospheric entry without disintegration. Why? Density's just a single physical property. Aerogels are *way* less dense than water, approaching the density of air, and they can stand ridiculous amounts of heat. Foams can be really good insulators.
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Feb 4, 2016 14:56
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ANIME AKBAR posted:I never understood why you can't just use a big fresnel lens to concentrate light onto smaller photocells. Is it not done because the lenses are more expensive than photocells per unit area? Advantages:
Pander posted:If you reduce the asteroid's density below that of water, I don't know how it would survive atmospheric entry without disintegration.
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Feb 4, 2016 15:01
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Phanatic posted:Why? Density's just a single physical property. Aerogels are *way* less dense than water, approaching the density of air, and they can stand ridiculous amounts of heat. Foams can be really good insulators. I just guessed the deceleration forces involved would explodey it into bits too small to bother going after. I know foam has pretty good crush and heat resistance, but didn't think dropping into an ocean would work. could easily be wrong.
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Feb 4, 2016 15:01
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Phanatic posted:Why? Density's just a single physical property. Aerogels are *way* less dense than water, approaching the density of air, and they can stand ridiculous amounts of heat. Foams can be really good insulators. Aerogels can withstand a lot of heat, but they have the tensile strength of tissue paper. Probably not gonna survive re-entry
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Feb 4, 2016 16:01
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Mr. Pool posted:Aerogels can withstand a lot of heat, but they have the tensile strength of tissue paper. Probably not gonna survive re-entry Nope. Plain silica aerogels are only about a dozen or so kPa, but there are crosslinked aerogels with useful strengths in both tension and compression (which seems more relevant for a re-entry scenario anyway). http://www.gizmag.com/llnl-ultralight-metamaterial/32589/ But in any event, I wasn't saying "turn it into an aerogel before reentry, problem solved," I was only using aerogel as an example of how considering density in isolation isn't a useful way to predict how materials behave, especially in a case where the re-entry forces you're trying to survive are related to the density of what you're re-entering.
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Feb 4, 2016 16:24
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ANIME AKBAR posted:I never understood why you can't just use a big fresnel lens to concentrate light onto smaller photocells. Is it not done because the lenses are more expensive than photocells per unit area? CombatInformatiker brought up a lot of the tradeoffs which basically is that concentrators make the system more complicated and the extra complexity, with the plumbing for cooling, mirrors which focus sunlight to intensities which can fry birds and ants, and the necessary mechanical tracking systems since the lenses don't work unless they are aligned to the sun, makes it harder to justify solar cells as a residential/commercial rooftop energy generation technology which requires little/no maintenance. Maybe it makes sense for utilities and there are small concentrator solar companies who are trying to peddle their wares to utilities. It's hard to justify the complexity though since the price of solar grade polysilicon has dropped by so much in the past 30 years. People back then talked about concentrator cells more than they do now. SunPower was originally a concentrator solar cell company. Under test conditions, solar concentration allows you to achieve higher efficiencies (so 10x solar concentration gives you more than 10x electricity per area of cell) because the solar concentration allows a higher electron and hole density buildup in the cell, and so the electrons and holes can be drawn out of the cell at a higher voltage. This ignores the the real world issue which is that not all sunlight is coming directly from the sun, a good fraction of it scatters off the stuff in the atmosphere and is diffuse. Normal unconcentrated flat plate cells can collect this sunlight. Concentrator cells throw it away since the lenses need to be pointed at the light source. I have been told that in most areas of the world, the diffuse light fraction is so high that concentrator cells don't really have a real-world efficiency advantage. silence_kit fucked around with this message at 16:53 on Feb 4, 2016 |
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Feb 4, 2016 16:38
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silence_kit posted:... Also, for most uses, efficiency isn't all that important. The key metric is cost per installed watt.
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Feb 5, 2016 14:45
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ohgod France to pave 1,000km of road with solar panels 
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Feb 5, 2016 15:29
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Hey that looks better than the stupid blocks of roadway that the initial proposal involved, it's basically a solar sticker. Why they aren't stickering it to roofing instead I don't know.
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Feb 5, 2016 16:36
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Those PV cobble stones look like a fun ride on rainy days and probably sound good as well.
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Feb 5, 2016 17:47
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Better France than here. At least it will end the bickering about how stupid the idea is. If it works, I'll gladly eat crow. I have rather severe doubts, however.
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Feb 5, 2016 17:49
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It's very different from replacing asphalt roads with an inch of rumble stripped glass on steel/concrete supports. If it's as durable as they think it is and it doesn't impair traction then it might be a thing. If they could make it so you could just roll it out from giant spools and then fuse it to the road with heat or something... sure why not. Installation costs are a big part of solar power so bypassing it by co-opting existing infrastructure is not that crazy. Still very suspicious about durability and traction though.
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Feb 5, 2016 18:01
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gaj70 posted:Also, for most uses, efficiency isn't all that important. The key metric is cost per installed watt. That doesn't mean that efficiency is not important. In fact it is probably more important now than before, with the cell costs plummeting and becoming smaller and smaller proportions of the total solar electricity cost. If someone were to come out with a solar cell technology tomorrow which was half as efficient per area, but only 45% of the cell cost per area, no one would go for it. Even though the cell cost "per watt" would be slightly smaller, all of the system costs which scale with area (like installation cost) would increase, and the cheaper cells would produce more expensive electricity.
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Feb 5, 2016 18:36
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CombatInformatiker posted:News from Wendelstein 7-X: So I've been trying to read up on nuclear power and the challenges involved in getting it to work. Out of curiosity what else would we need to address in order to make a functional fusion power plant assuming everything in Wendelstein goes as planned and nothing else comes up?
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Feb 5, 2016 18:46
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MechanicalTomPetty posted:So I've been trying to read up on nuclear power and the challenges involved in getting it to work. Out of curiosity what else would we need to address in order to make a functional fusion power plant assuming everything in Wendelstein goes as planned and nothing else comes up? There's a long way to go yet on fusion. They have to come up with a process that actually works consistently enough and simply enough to make commercial power possible. Getting to break-even is a big milestone at the moment (the process produces as much energy as it consumes to produce the fusion in the first place). They've spent 50 years in incremental improvements to get past that. Commercial viability will need an energy output 10-20 times greater than break-even, or better, though. Beyond that, they'll need a system that can run continuously, constantly injecting fuel and extracting the products - if they can hit 20x break even, but it takes a month to set it up for a 1-second run, it's still not viable. That's probably a less difficult problem to solve than just getting to that point, but it's still a problem to be solved. Then they'll need to have a method of extracting the heat reliably, so they can boil water and spin turbines. Once they have all that figured out, they'll need to go to work designing and building a commercially useful system. That will probably take another decade at least all by itself. I don't see a commercial fusion reactor existing before 2100, and that may be optimistic.
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Feb 5, 2016 19:02
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Speaking of fusion... it's advertised as clean (because the fusion products aren't scary), which is partly true, but what kind of low-level secondary waste gets created as a theoretical by-product? I'm talking about neutron irradiated containment vessels and moderators, or contaminated water from steam generators. That stuff seems like the vast majority of nuclear waste for fission. The actual fissile material is the small stuff, no?
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Feb 5, 2016 19:22
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MechanicalTomPetty posted:So I've been trying to read up on nuclear power and the challenges involved in getting it to work. Out of curiosity what else would we need to address in order to make a functional fusion power plant assuming everything in Wendelstein goes as planned and nothing else comes up? A whole shitload of things. The 7-X is, again, a research tool. A commercial fusion plant will need to be able to sustain the fusion reaction pretty much indefinitely. Coal plants and nuclear plants do not randomly stop burning coal or uranium while the operators sit around trying to figure out what just made the thing turn itself off. A commercial fusion plant will need to do this with a fusion gain factor of 20 (that is to say, that the amount of power it needs to put into the reactor to keep the reaction going will need to be only 5% of the fusion power being produced). That is a very very big deal, 7-X will not do that. Second, we need to figure out what to build a commercial fusion reactor out of. This is, arguably, even a *bigger* deal. D-T fusion produces a 3.5 MeV alpha particle and a 14 MeV neutron. The alpha particle will interact with the fuel plasma, slowing down and transferring its kinetic energy to it to keep it nice and hot, but the neutron will fly right out of the plasma and into the reactor vessel. On one hand, this is good, because that's how you're going to get useful energy out of the reactor. On the other hand, it's bad, because over the expected lifetime of your reactor that means that every single atom in the reactor vessel is going to be struck and displaced by a neutron well over 100 times (15 displacements per atom per year of operation). That's bad because it does really bad things to all the known materials that you might want to build a fusion reactor vessel out of. It creates voids, actually does some transmutation, you wind up with little bubbles of He in those voids, the bulk material becomes brittle, its thermal conductivity goes does, it swells up, bits flake off. So you need to find a material for your reactor structure that doesn't do that under intense sustained neutron bombardment, *and* also has suitable material properties to contain a 50-million-degree plasma. And the parts of that reactor structure that are actually exposed to the huge amounts of radiant energy coming off the plasma need to be able to withstand that as well, without sputting their surfaces off into it and poisoning the reaction. And you'd really like to minimize the amount of your reactor vessel that gets transmuted into nasty radioisotopes. D-T fusion is insanely neutron rich, to the extent that it's difficult to even explore this materials regime because you need one hell of a high-energy neutron source; there's a facility being built to do this but it's pretty far behind schedule. Third, you need to do all the gritty engineering work of actually turning this into a power plant. How do you produce electricity? The general gist of the idea is that you surround the reactor vessel in a blanket of lithium, the neutrons escaping the reactor vessel will eventually bounce around in that lithium, depositing their kinetic energy and transmuting some of the lithium to tritium. Use the hot lithium to boil water to turn a generator etc etc, extract the tritium so you can feed it into the reactor as fuel. Given that you've done the previous steps, this is the easy part, but it's still significant, nobody's done it, and none of the research plants under construction are even going to try to do it. And again, for commercial power you want to be able to do this all without having to shut down the reactor very often. Infinite Karma posted:Speaking of fusion... it's advertised as clean (because the fusion products aren't scary), which is partly true, but what kind of low-level secondary waste gets created as a theoretical by-product? Well, the containment vessel's certainly going to be irradiated, but neutron activation half-lives are short; decommissioned fission reactor vessels are low-level waste (although see above regarding the relative neutron abundance of fusion vs. fission). The nasty stuff from fission are the moderate half-life fission products, the ones that are radioactive enough to gently caress your poo poo up but with a half-life long enough to keep loving your poo poo up for a long time: cesium-137, strontium-90, technetium-99, that sort of thing. A fusion reactor won't produce any fission fragments, which is a big benefit from a marketing perspective. Phanatic fucked around with this message at 19:31 on Feb 5, 2016 |
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Feb 5, 2016 19:23
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An interesting consideration I've heard is that fusion might require 10GW+ plant designs to be economical, but we'd have to really re-engineer the grid to support such massive plants that thus far, have little early capacity to ramp at all.
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Feb 5, 2016 19:52
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Or build a really really big flywheel under the plant. Maybe try to correct earth's axial tilt in the process. I mean if you think about it tidal power is basically just harvesting lunar inertia, I see nothing wrong with maybe powering human civilization by slowing down the rotation of the earth slightly.
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Feb 5, 2016 19:55
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Deteriorata posted:Beyond that, they'll need a system that can run continuously, constantly injecting fuel and extracting the products - if they can hit 20x break even, but it takes a month to set it up for a 1-second run, it's still not viable. That's probably a less difficult problem to solve than just getting to that point, but it's still a problem to be solved. According to a talk I saw from a guy at Lawrence Livermore this is 100% the biggest hurdle.
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Feb 5, 2016 20:54
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With the operations regime things like ITER or Wendelstein are aiming for, from a layman's perspective it sounds like you could ideally just run reactors next to each other that are on alternating half hour ish refuel/burn cycles
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Feb 5, 2016 22:00
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I CANNOT EJACULATE WITHOUT SEEING NATIVE AMERICANS BRUTALISED!
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Another problem is maintenance costs. Parts, for tokamak reactors anyways, need to be cast as one huge piece. So if some part of it goes bad, you need a whole new tokamak, essentially. Which isn't commercially viable.
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Feb 6, 2016 03:09
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gently caress You And Diebold posted:Another problem is maintenance costs. Parts, for tokamak reactors anyways, need to be cast as one huge piece. So if some part of it goes bad, you need a whole new tokamak, essentially. Which isn't commercially viable. I've never heard that, but reactor vessels are built to last the life of the reactor anyway, even for fission plants.
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Feb 6, 2016 03:23
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Phanatic posted:Second, we need to figure out what to build a commercial fusion reactor out of. This is, arguably, even a *bigger* deal. D-T fusion produces a 3.5 MeV alpha particle and a 14 MeV neutron. The alpha particle will interact with the fuel plasma, slowing down and transferring its kinetic energy to it to keep it nice and hot, but the neutron will fly right out of the plasma and into the reactor vessel. On one hand, this is good, because that's how you're going to get useful energy out of the reactor. On the other hand, it's bad, because over the expected lifetime of your reactor that means that every single atom in the reactor vessel is going to be struck and displaced by a neutron well over 100 times (15 displacements per atom per year of operation). That's bad because it does really bad things to all the known materials that you might want to build a fusion reactor vessel out of. It creates voids, actually does some transmutation, you wind up with little bubbles of He in those voids, the bulk material becomes brittle, its thermal conductivity goes does, it swells up, bits flake off. So you need to find a material for your reactor structure that doesn't do that under intense sustained neutron bombardment, *and* also has suitable material properties to contain a 50-million-degree plasma. And the parts of that reactor structure that are actually exposed to the huge amounts of radiant energy coming off the plasma need to be able to withstand that as well, without sputting their surfaces off into it and poisoning the reaction. And you'd really like to minimize the amount of your reactor vessel that gets transmuted into nasty radioisotopes. D-T fusion is insanely neutron rich, to the extent that it's difficult to even explore this materials regime because you need one hell of a high-energy neutron source; there's a facility being built to do this but it's pretty far behind schedule. What to do with the neutrons is definitely something that doesn't have a satisfactory answer yet; getting better than break-even and fuel reloading are the more frequently cited challenges. As you mentioned, 14 MeV neutrons really gently caress things up, but we'd like to extract that energy and use it. I'm not sure this has been brought up in this thread yet but my best guess for our eventual solution will be running fusion-fission hybrid reactors since you basically kill two birds with one stone - you get rid of the neutrons and turn that 14 MeV of kinetic energy into a 200 MeV fission, the heat energy from which we already know how to extract. Additionally, 14 MeV is high enough energy that you can straight up fission thorium instead of using the roundabout decay process proposed for things like the LFTR, or you can burn DU or spent fuel. Since you have a super high flux neutron source, you don't even need your fission fuel in a critical geometry since you're no longer relying on the chain reaction. There will obviously be a lot of engineering challenges with this solution (like any), and of course you *still* need to solve the fuel reloading (and breeding and neutron economy, since many would be used for fission) and materials issues, but it's a pretty neat idea in that it addresses several issues simultaneously. In addition to the engineering issues laid out, there are also some theoretical problems we need to solve, like the heat loss problem. We're making progress but we still have quite a ways to go before we have even a prototype commercial-style fusion reactor.
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Feb 6, 2016 16:43
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Would amorphous metals fare better under neutron radiation?
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Feb 6, 2016 17:08
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Phanatic posted:I've never heard that, but reactor vessels are built to last the life of the reactor anyway, even for fission plants. http://news.mit.edu/2015/small-modular-efficient-fusion-plant-0810 quote:The stronger magnetic field makes it possible to produce the required magnetic confinement of the superhot plasma — that is, the working material of a fusion reaction — but in a much smaller device than those previously envisioned. The reduction in size, in turn, makes the whole system less expensive and faster to build, and also allows for some ingenious new features in the power plant design. The smaller size and modular design brings the up front and long term maintenance costs much lower, which means it can be economically viable for research, and eventually consumer power production sooner https://www.dur.ac.uk/dei/news/?itemno=25508 quote:The study considers recent advances in high temperature superconductors, which could be used to build the powerful magnets that keep the hot plasma in position inside the containing vessel, called a tokamak, at the heart of a fusion reactor.
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Feb 6, 2016 22:09
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gently caress You And Diebold posted:The smaller size and modular design brings the up front and long term maintenance costs much lower, which means it can be economically viable for research, and eventually consumer power production sooner Ooof, a rather damning quote in there “Obviously we have had to make assumptions, but what we can say is that our predictions suggest that fusion won’t be vastly more expensive than fission.”
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Feb 6, 2016 22:12
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