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Dusseldorf posted:Why would that matter? The sun isn't focused on some point up in the sky and temporarily blocking a solar thermal plant won't cause a drop in output. It's also about environmental consideration. Fresh water, fair weather, wide open areas, and sunshine are four ingredients that rarely come together much. The best locations for solar power are far removed from both large population centers and large bodies of fresh water. A nuke plant is small enough to fit along a Tennessee River, solar can't do that. Creating massed concentrated solar power centers is trading one environmental drawback (CO2 Generation) for another (Water scarcity).
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# ? Sep 27, 2013 03:38 |
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# ? May 9, 2024 23:19 |
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Dusseldorf posted:Which method of power generation has no environmental footprint? Most assuredly not solar thermal that's literally covering an entire 25,000 square mile area. At peak performance it would put out 3x the current power needs of the country but a) night time exists and b) day time is never continuous 100% output. And this is before considering the enviromental footprint of the neccesary energy storage facilities so that there's power at night.
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# ? Sep 27, 2013 03:44 |
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Install Windows posted:And this is before considering the enviromental footprint of the neccesary energy storage facilities so that there's power at night. You don't necessarily need storage. Solar is peak generation and unless you have an only solar grid you would use nuclear or coal for baseline generation.
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# ? Sep 27, 2013 03:47 |
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Hobo Erotica posted:We're talking about ~ 400 MW, which is a fair whack, and about half of one of the plants you mentioned, not really 'nearly nothing'. Actually it's more like 123 MW on average (that's their estimate of yearly energy). At best it might be 377 MW of load-following power, which admittedly might make it a nice deal. Of course, if that is the case, then solar plants will be limited to a very small part of our overall electricity supply.
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# ? Sep 27, 2013 04:01 |
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Dusseldorf posted:You don't necessarily need storage. Solar is peak generation and unless you have an only solar grid you would use nuclear or coal for baseline generation. It would be insane to say the least to cover the whole desert or even a significant portion of the desert just to use for peak generation. Or just, in general, to dedicate the same amount of land spread all over to solar that was just meant to be used at peak.
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# ? Sep 27, 2013 04:02 |
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CommieGIR posted:But lets take a quick look: This is cool, can you do it for coal? Also another way of thinking about the space is to compare it to the homes powered. Article says 140,000 homes, on 3,500 acres (yikes, not 1,600) - so that's 0.025 acres per home. If a home is say 2000 sq ft, that's 0.45 acres, so its equivalent to using roughly half the roof space of a house to power it. Without factoring in transmission losses of course. Seems like a fairly reasonable deal. hobbesmaster posted:Also unfortunately these solar plants are going to require really long transmission lines and probably not be able to be operated by the same company if they can even be in the same state. This isn't unique to solar thermal technology though is it? Just to any power plant that you build in that area. As for the companies: "The first successfully operating unit will sell power to California’s Pacific Gas and Electric, as will Unit 3 when it comes online in the coming months. Unit 2 is also set to come online shortly, and will provide power to Southern California Edison." Pander posted:But it is nowhere near as disconcerting as the water intake required. Again, how unique is this to solar thermal, as compared to coal or nuclear? They're all running on the same principle of making steam. Are we talking about the water needed to keep the heliostats clean (in which case you'd need the same for PV), or just to spin the turbines? In other words, are you saying this is bad technology, or just a bad place to put a power plant? Also the article says: "The sunlight concentrated from these mirrors heats up water contained within the towers to create super-heated steam which then drives turbines on the site to produce power." Does that mean they're not using molten salts? And if so, does that mean it doesn't have overnight storage? I couldn't find a clear answer on the website either. The website is pretty cool though: http://ivanpahsolar.com/ And since we all know I love videos, here's a good one of the construction: https://www.youtube.com/watch?v=0wVXgGTrPro In any case, has there been any press over there about it? Has it been positive, negative, or balanced? I mean it's the biggest in the world, is anyone going all "USA!" over it?
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# ? Sep 27, 2013 04:27 |
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Dusseldorf posted:Why would that matter? The sun isn't focused on some point up in the sky and temporarily blocking a solar thermal plant won't cause a drop in output. It was a joke. Hobo Erotica posted:In any case, has there been any press over there about it? Has it been positive, negative, or balanced? I mean it's the biggest in the world, is anyone going all "USA!" over it? There has been a bit of press for it, I know its going around Facebook circles at least, and I say its a good showing of what we can do with Solar Power. But here is the long and short of it: Their target audience is California, right over the border, who imports a lot of energy because they've shutdown most of their nuclear plants and are replacing them with.... ...natural gas. Ironically, one nuclear plant in California makes up about 9% of their total generating power. CommieGIR fucked around with this message at 04:41 on Sep 27, 2013 |
# ? Sep 27, 2013 04:38 |
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Hobo Erotica posted:Are we talking about the water needed to keep the heliostats clean (in which case you'd need the same for PV), or just to spin the turbines? quote:In other words, are you saying this is bad technology, or just a bad place to put a power plant? quote:Does that mean they're not using molten salts? And if so, does that mean it doesn't have overnight storage?
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# ? Sep 27, 2013 04:52 |
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Hobo Erotica posted:
quote:Again, how unique is this to solar thermal, as compared to coal or nuclear? They're all running on the same principle of making steam. You don't need to put a nuclear plant in the desert.
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# ? Sep 27, 2013 13:54 |
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Hobo Erotica posted:This isn't unique to solar thermal technology though is it? Just to any power plant that you build in that area. As for the companies: Yes. If you put some gas turbines the size of a 747 in the desert you'd have the same problems. Well actually not really the water ones because they don't need water. The point is that you can put those turbines right next to where you need it instead of some massive operation in the middle of nowhere.
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# ? Sep 27, 2013 14:02 |
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hobbesmaster posted:Yes. If you put some gas turbines the size of a 747 in the desert you'd have the same problems. Well actually not really the water ones because they don't need water. What are you fuel costs though? How much gas does a 400 MW gas plant go through in a day? What's the emissions intensity? I get the point that the land footprint of large scale solar necessitates being put further away from cities, but after looking around on google maps, it's 48 miles from Vegas. If you move that map around, you could build at least another 10 much closer than that to the city. Some even within or just on the edge of city limits it looks like. Maybe just a single tower in some places instead of the triple. That's getting up towards 4 GW. You'd hope the costs would come down a bit on that scale, cos it'd cost a bit of course, but could something like that theoretically work in Vegas?
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# ? Sep 27, 2013 16:02 |
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Hobo Erotica posted:What are you fuel costs though? How much gas does a 400 MW gas plant go through in a day? What's the emissions intensity? The problem with both gas and coal, beyond their emissions, is the fact that both their fuel sources are dead ends and ecologically damaging in their collection
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# ? Sep 27, 2013 16:08 |
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Hobo Erotica posted:What are you fuel costs though? How much gas does a 400 MW gas plant go through in a day? What's the emissions intensity? http://en.wikipedia.org/wiki/Cost_of_electricity_by_source Emissions are bad, but the gas is 1/3 as expensive. Economically renewables make no sense so unless gov't does something to change that...
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# ? Sep 27, 2013 16:17 |
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Can anyone tell me how much gas a 400 MW plant would use in a day though? And the price? (I know it's fairly simple but I've got another assignment to do and I'm just curious.) Here's one I prepared earlier for Coal for example - could probably use a fact check actually: quote:Coal has an energy content of about 37 MJ/kg. Now if you’ve got a plant that’s rated at 1 GW, that means 1 billion Watts. A Watt is a joule per second, so 1 billion watts is 1 billion joules per second. Now with coal’s energy content of 37 Million joules per kilo, to get that billion joules per second, you need to burn 27 kg of coal per second. Or at least you would, if these plants were 100% efficient – as in converted 100% of the energy in the coal by burning it. But they generally only run at around 35%. So you actually need to burn around 80 kg of coal a second. Which is 4.8 tonnes per minute, or 288 tonnes per hour, or 7,000 tonnes per day. 2.5 million tonnes per year. Just in one power plant. That’s X truck loads. Bucky Fullminster fucked around with this message at 16:53 on Sep 27, 2013 |
# ? Sep 27, 2013 16:36 |
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Hobo Erotica posted:Can anyone tell me how much gas a 400 MW plant would use in a day though? And the price? http://www.eia.gov/tools/faqs/how-much-coal-natural-gas-or-petroleum-used-generate-kilowatt-hour-electricity
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# ? Sep 27, 2013 16:38 |
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Hobo Erotica posted:Can anyone tell me how much gas a 400 MW plant would use in a day though? And the price? That passage is super hosed. 1 GW = 1e9 W. not 1e3 W. The numbers are all correct but you need to fix those units.
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# ? Sep 27, 2013 16:43 |
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John McCain posted:
Hahaha holy poo poo what the hell. It's been like that for a long time, I must have just numbed myself to it. Thanks.
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# ? Sep 27, 2013 16:51 |
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I'm glad to know there's a power plant out there just for my computer + air conditioning.
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# ? Sep 27, 2013 16:52 |
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Hobo Erotica posted:Hahaha holy poo poo what the hell. It's been like that for a long time, I must have just numbed myself to it. Thanks. You just forgot an M. That's a neat breakdown actually, between that and the cube-o-stuff graphic it's a pretty compelling companion to any fossil fuel argument.
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# ? Sep 27, 2013 17:28 |
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Just noting the discussion about the space the new solar plant takes up: don't forget to account for the space all the other power plants require - such as open pit mining for coal and uranium, disposal and storage of waste such as fly ash, tar, sludge ponds, and long-term radiological material storage, setback distances from populated areas from smoke plumes, transport passageways for massive man-rowing plants, and total land flooded from large-scale hydro.
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# ? Sep 27, 2013 23:29 |
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Guigui posted:Just noting the discussion about the space the new solar plant takes up: don't forget to account for the space all the other power plants require - such as open pit mining for coal and uranium, disposal and storage of waste such as fly ash, tar, sludge ponds, and long-term radiological material storage, setback distances from populated areas from smoke plumes, transport passageways for massive man-rowing plants, and total land flooded from large-scale hydro.
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# ? Sep 27, 2013 23:35 |
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Guigui posted:Just noting the discussion about the space the new solar plant takes up: don't forget to account for the space all the other power plants require - such as open pit mining for coal and uranium, disposal and storage of waste such as fly ash, tar, sludge ponds, and long-term radiological material storage, setback distances from populated areas from smoke plumes, transport passageways for massive man-rowing plants, and total land flooded from large-scale hydro. You are completely ignoring the fact that coal plants and gas plants actively vent radioactive isotopes and pollutants into the air as part of their operation. Outside of the radioactive isotopes at the fuels end of life, nuclear plants release very little beyond steam if operating properly. Especially if it were a NEW reactor design or even a molten thorium reactor.
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# ? Sep 28, 2013 01:49 |
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hobbesmaster posted:http://en.wikipedia.org/wiki/Cost_of_electricity_by_source I think that we could solve a lot of problems with renewable vs nuclear vs gas vs coal if we just internalized all of the hidden costs that some types incur (especially coal). For example, what if we required coal and gas plants to capture 100% of their emissions? And what if we required mining/fracking operations to sock away a certain amount of cash for ecological restoration projects? And huge solar tracts would have to pay into ecological habitat funds because of the vast tracts of land that can be displaced by solar farms. I imagine that nuclear would probably be the cheapest, if not second cheapest to renewable energy, if we just internalized the real costs of energy.
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# ? Sep 28, 2013 07:25 |
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I find the discussion of prices for coal and gas to be particularly unconvincing because they seem to be quite changeable. Surely demand for these raw materials is only going to continue to increase so the price will also increase? (at least until they are inevitably abandoned in favor of more sustainable alternatives) I mean there is only ever going to be so much gas that doesn't require drastic environmental damage to extract no? If CSG installations are already being fast-tracked before the science is in on the environmental impact isn't that a good indicator that the price of gas is already too high?
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# ? Sep 28, 2013 11:26 |
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Flaky posted:I find the discussion of prices for coal and gas to be particularly unconvincing because they seem to be quite changeable. Surely demand for these raw materials is only going to continue to increase so the price will also increase? (at least until they are inevitably abandoned in favor of more sustainable alternatives) I mean there is only ever going to be so much gas that doesn't require drastic environmental damage to extract no? If CSG installations are already being fast-tracked before the science is in on the environmental impact isn't that a good indicator that the price of gas is already too high? Demand is going to increase, but also (at least for petroleum related stuff) all of the cheap stuff is more or less gone. For the new stuff like fracking it's simply not economical below a certain price per barrel. Fortunately, it appears that that price is just enough to get people to shift over to more renewable energy sources (and if demand falls, fracking becomes economically unviable, which means we need different tech! And so on).
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# ? Sep 28, 2013 13:52 |
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CommieGIR posted:You are completely ignoring the fact that coal plants and gas plants actively vent radioactive isotopes and pollutants into the air as part of their operation. Of course - I ignored that part of my argument as my question was focused solely on the total land footprint needed to operate X type of powerplant. You are correct, however, in that coal plants (and other fossil fuel burning machinery) send up all sorts of materials. I wanted to point out that any power plant that requires fuel to operate must also consider the landmass used to extract that fuel in the power plant's total land-use calculation. Comparing the new solar power plant discussed earlier in the thread isn't so big, when you consider that other power plants require the same, if not more, space to mine their fuels and a facility to refine the materials. The only power plant I can see, so far that doesn't take up any active land would be Denmark's giant array of offshore windmill turbines.
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# ? Sep 28, 2013 15:33 |
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Guigui posted:Of course - I ignored that part of my argument as my question was focused solely on the total land footprint needed to operate X type of powerplant. You are correct, however, in that coal plants (and other fossil fuel burning machinery) send up all sorts of materials. And coal is on a completely different scale, since the material needed is on the order of millions of tons to power the world's coal plants. I've traveled through the flat-top coal country even to feel pretty lovely about that.
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# ? Sep 28, 2013 15:43 |
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Pander posted:How many plants can a few mines power, though? It's not like each nuclear plant has its own personal uranium mine, is it? A dozen or so mines could produce enough uranium to power the world's fleet, meanwhile it would take thousands of plants similar to Ivanpah to produce an equivalent amount of energy. That and the materials solar panels are made of presumably require some sort of mining as well.
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# ? Sep 28, 2013 15:45 |
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computer parts posted:That and the materials solar panels are made of presumably require some sort of mining as well.
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# ? Sep 28, 2013 15:51 |
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Pander posted:I dunno. Even on a per-megawatt-produced basis I'd bet Ivanpah required a lot less construction material than a nuke plant. Nuke plants have a LOT of steel, iron, cement, etc. Uncountable stretches of piping, etc. I was thinking more rare earths.
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# ? Sep 28, 2013 15:53 |
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Every energy system needs mining, either for fuel or component parts, that will never go away, moving to nuclear means a lot LESS mining, and more emphasis on less destructive mining methods for more energetic fuel sources means less mines and better overall environment. Coal and Natural Gas are just nasty overall, either through the strip mining used to get the billions of tons of coal we burn a year, or leaking methane released by accident during fracking, which is a potent greenhouse gas. I mean, its like the Prius: Sure, it presents a green environmentally friendly car, but in fact the mining needed to produce it is probably far more destructive than the mining needed for a normal SUV.
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# ? Sep 28, 2013 15:53 |
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Is it still kosher to bring up the Nuclear is still cheaper than solar wrt Finland and Germany or did something definitive come out trashing it?
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# ? Sep 28, 2013 15:55 |
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QuarkJets posted:And what if we required mining/fracking operations to sock away a certain amount of cash for ecological restoration projects? In most of the civilized world, mining permits are already subject to a similar principle:
Edit: whoops, I neglected the second part of your sentence. I know very little about fracking. I think that they're subject to the same rules but (because it's a relatively young business and enjoys political support) the bond amounts are relatively small. Pander posted:I dunno. Even on a per-megawatt-produced basis I'd bet Ivanpah required a lot less construction material than a nuke plant. Nuke plants have a LOT of steel, iron, cement, etc. Uncountable stretches of piping, etc. 290 MW :: 39 000 tons ( 1154 MW :: 110 000 tonnes (UK analysis of AP1000) Edit: the solar numbers here are for a PV facility rather than Ivanpah as I had originally claimed. I'll include an Ivanpah value if/when I get an answer from Gestamp. Of course, a nuclear power plant is also going to require a lot more concrete (and a relatively small amount of costly special alloys). On the other hand, it gets better "mileage" out of its construction materials by maintaining a >90% capacity factor. GulMadred fucked around with this message at 19:22 on Sep 28, 2013 |
# ? Sep 28, 2013 16:33 |
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LP97S posted:Is it still kosher to bring up the Nuclear is still cheaper than solar wrt Finland and Germany or did something definitive come out trashing it? It comes from a fairly well-established energy/environment research group, The Breakthrough Institute. It's been criticized by readers in the comment boxes (natch), but as far as I could tell with google search it hasn't been rebuked by anyone with more expertise yet. Here's the original study: http://thebreakthrough.org/index.php/programs/energy-and-climate/cost-of-german-solar-is-four-times-finnish-nuclear/ They also made a follow-up concerning criticism of that study: http://thebreakthrough.org/index.php/voices/michael-shellenberger-and-ted-nordhaus/no-solar-way-around-it/ And a follow-up on that follow-up that explains how/why nuclear scales so well: http://thebreakthrough.org/index.php/programs/energy-and-climate/nuclear-has-scaled-far-more-rapidly-than-renewables/ They've also conducted studies on nuclear vs. solar subsidies, specifically in California: http://thebreakthrough.org/index.php/programs/energy-and-climate/subsidies-for-solar-two-times-higher-than-for-nuclear-in-california/ Unfortunately, I can't quote all of these articles, but I will quote the tables from one of their most recent articles that's very relevant to the current discussion about environmental footprint and resource usage: http://thebreakthrough.org/index.php/programs/energy-and-climate/nuclear-has-one-of-the-smallest-footprints/ http://thebreakthrough.org/index.php/programs/energy-and-climate/nuclear-has-one-of-the-smallest-footprints/ posted:Land Footprint Their articles are well-sourced with information that's the most recent and accurate you can realistically find for free. Edit - The commenters on that site are pretty awesome too. One of them made a graphic illustrating land use of wind versus nuclear: http://jmkorhonen.net/2013/09/04/graphic-of-the-week-comparing-land-use-of-wind-and-nuclear-energy/ Office Thug fucked around with this message at 19:01 on Sep 28, 2013 |
# ? Sep 28, 2013 18:51 |
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computer parts posted:I was thinking more rare earths. There are no rare earths metals used in any current photovoltaic technology. The OP is wrong, I told them to edit it.
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# ? Sep 28, 2013 19:40 |
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Dusseldorf posted:There are no rare earths metals used in any current photovoltaic technology. The OP is wrong, I told them to edit it. ....um, source? Only last year were they announcing new solar panels that use LESS rare earth metals, not NO rare earth metals. Anybody got a link to what the current makeup of solar panels is? CommieGIR fucked around with this message at 19:45 on Sep 28, 2013 |
# ? Sep 28, 2013 19:43 |
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CommieGIR posted:....um, source? Only last year were they announcing new solar panels that use LESS rare earth metals, not NO rare earth metals. The most popular type of solar cell is the crystalline silicon solar cell. Silicon is extracted from sand, which is very plentiful. Edit: Here's a link to a long report from a couple of years ago. It claims that 90% of installed solar photovoltaic capacity is crystalline silicon solar cells. https://www.google.com/url?sa=t&sou...7KGXCYFgYVnTf_Q It may be worth emphasizing that the chart that Dusseldorf is linking below is a theoretical chart. Almost all of the materials on that chart currently aren't technologically relevant to photovoltaics. Edit 2: I just skimmed the paper he posted. Those numbers are calculated using almost the theoretical limits of each material. Only a few solar cell materials on that chart in practice, of which crystalline silicon is one, approach their theoretical limits. This is immaterial (ha!) to Dusseldorf's point but it may be worth pointing out. silence_kit fucked around with this message at 21:48 on Sep 28, 2013 |
# ? Sep 28, 2013 19:48 |
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CommieGIR posted:....um, source? Only last year were they announcing new solar panels that use LESS rare earth metals, not NO rare earth metals. Here's a chart of basically all the solar materials listed with analysis on the scalability of the technology based on earth abundance. Although many of the materials such as Tellurium are not earth abundant none are rare earth metals. Cyrus Wadia, Paul Alivisatos, Daniel Kammen, Enviromental Science & Technology 43, 2072-2077 (2009)
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# ? Sep 28, 2013 19:53 |
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Dusseldorf posted:Here's a chart of basically all the solar materials listed with analysis on the scalability of the technology based on earth abundance. Although many of the materials such as Tellurium are not earth abundant none are rare earth metals. Okay, thanks for the source, I was not around for the previous discussion.
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# ? Sep 28, 2013 20:36 |
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# ? May 9, 2024 23:19 |
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CommieGIR posted:Okay, thanks for the source, I was not around for the previous discussion. I guess for the overview, the use of earth abundant materials is extremely important in evaluating new solar materials. It's also a huge drawback from the current CdTe cells that are made. Nevertheless, by far the bulk of production and efficiency leaders come from silicon cells where there is no earth abundance problems at all. The availability of rare earth metals (neodymium, samarium) is a big issue for wind power which requires powerful permanent magnets that can withstand high heat.
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# ? Sep 28, 2013 20:44 |