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I'm confused how solar energy being cleaner is non-obvious. What am I missing here?
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# ? Sep 10, 2012 03:19 |
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# ? May 9, 2024 23:58 |
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Winks posted:I'm confused how solar energy being cleaner is non-obvious. What am I missing here? The cost of making/mining the materials to make the panels/storage system, I imagine (especially if either of those don't have a terribly long shelf life).
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# ? Sep 10, 2012 03:21 |
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Cartoon posted:It's dated (2008) and Photovoltaic is considered expensive but it is a decent link to have unless there is a better one http://www.scientificamerican.com/article.cfm?id=solar-cells-prove-cleaner-way-to-produce-power So would wind power, nuclear power, etc. "It wouldn't cut air pollution enough" isn't a reason people don't think solar is a usable global solution.
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# ? Sep 10, 2012 03:42 |
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The study reports on US panels, though. China-made panels would be somewhat different. Also fails to report "90%" in relation to what: Coal releases something like 4 times the CO2 of gas.
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# ? Sep 10, 2012 13:10 |
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MrL_JaKiri posted:So would wind power, nuclear power, etc. "It wouldn't cut air pollution enough" isn't a reason people don't think solar is a usable global solution. Aureon posted:The study reports on US panels, though. China-made panels would be somewhat different. The cited report posted:a fraction of the near one kilogram (2.2 pounds) of greenhouse gases emitted by a coal-fired power plant per kilowatt-hour. The Chinese situation may very well be different. The report suggests that (in the US) the situation in 2012 may very well be different (The report suggests manufacturers are moving to solar powered production). If there is a better study please link it to improve our collective knowledge.
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# ? Sep 11, 2012 04:32 |
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Pvt Dancer posted:I work as an engineer on offshore wind parks so I know a fair amount about them. If anyone has any questions I'll be happy to answer. This sounds interesting, could you tell us some more? Where do you work, what do you, what is it like on the job, what's it like in the market place? As I understand, off shore wind farms are a toss up between getting better winds and using less land on the one hand, but being harder to build and maintain on the other. How does yours fit in to that? Aureon posted:Biomass is a a smokescreened fossil fuel. I should clarify here too, the difference between 1st and 2nd generation Biofuels. 1st generation biofuels are crops grown specifically for fuel. These are bad, almost as bad as oil, for the reasons you mentioned. 2nd generation biofuels use agricultural offcuts, which would otherwise end up in landfill (or perhaps compost). Any self respecting biodiesel operator will only ever use 2nd generation fuels, and when I spoke to BZE they said the fuels in their plan were 2nd generation as well.
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# ? Sep 11, 2012 05:08 |
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Good news everyone: we won't have to worry about global warming much longer because we'll just accelerate the whole thing to catastrophic levels once we start tapping methane hydrates, which also happens to be closely tied to of the catastrophe scenarios for global warming. You can read a little bit about it here.
marmot25 fucked around with this message at 05:45 on Sep 11, 2012 |
# ? Sep 11, 2012 05:40 |
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marmot25 posted:Good news everyone: we won't have to worry about global warming much longer because we'll just accelerate the whole thing to catastrophic levels once we start tapping methane hydrates, which also happens to be closely tied to of the catastrophe scenarios for global warming. You can read a little bit about it here. I don't know much about whether it's a good idea or not, but tapping the deposits for fuel is different to just releasing them into the atmosphere. You're right that those deposits do form one of the biggest threats to the climate though.
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# ? Sep 11, 2012 07:19 |
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Hobo Erotica posted:I don't know much about whether it's a good idea or not, but tapping the deposits for fuel is different to just releasing them into the atmosphere. You're right that those deposits do form one of the biggest threats to the climate though. It's currently sequestered carbon that we will be releasing into the atmosphere, and unless we're planning to do some fancy sequestration when we burn it it's a bad idea. From a warming perspective I suppose it's better that we burn it first, given that methane has a stronger greenhouse gas effect, but it's still pretty bad. The true catastrophe scenario is that the oceans warm enough to the cause wholesale release of these deposits. I just think it's interesting that we'd consider their slow release acceptable.
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# ? Sep 11, 2012 07:39 |
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marmot25 posted:It's currently sequestered carbon that we will be releasing into the atmosphere, and unless we're planning to do some fancy sequestration when we burn it it's a bad idea. From a warming perspective I suppose it's better that we burn it first, given that methane has a stronger greenhouse gas effect, but it's still pretty bad. The true catastrophe scenario is that the oceans warm enough to the cause wholesale release of these deposits. I just think it's interesting that we'd consider their slow release acceptable. Aren't all fossil fuels sequestered carbon that'll be released into the atmosphere? At least with methane you get a better energy to CO2 released ratio. I agree that methane leakage and catastrophic release are very large concerns here.
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# ? Sep 11, 2012 09:17 |
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Cartoon posted:You'd be surprised how many people want to know the answer to the question posed and the link is provided for informational purposes. Where the 'solar (photovoltaic) is a usable global solution' was claimed/implied is anyone's guess. Actually, the study is just theory, without going on how the manufacturer's energy is produced. Solar EROEI, ofcourse, varies: This study for examples, finds between 3-10:1 for operating installations, (not including dismantling), which means the cut of emissions in relation to the energy used is 66-90%. (Producing solar panels, which is energy-intensive, with solar energy, which goes at around three times market rate, seems not within economic possibility at the moment). [Basically, this study says "there's no consensus on where exactly the EROEI anything is, because facts themselves vary"] It's worth to note that hydro itself varies between 250+:1, which are the good sites, and less than 10:1, which are the scrap sites. Wind is rapidly going that way, with operational average of 18:1 (And the best sites in the world have been taken, so expect any newly built plant to be far less than that) (on wind power) quote:The operational studies provide lower EROIs because the simulations run in conceptual models appear to assume conditions to be more favorable than actually experienced on the ground.
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# ? Sep 11, 2012 12:08 |
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Dusseldorf posted:Aren't all fossil fuels sequestered carbon that'll be released into the atmosphere? At least with methane you get a better energy to CO2 released ratio. I agree that methane leakage and catastrophic release are very large concerns here. That's correct, although I would guess that there's a much higher risk of an accident simply releasing a bunch of methane into the atmosphere, so it's a bit more hazardous than liquid carbon stores
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# ? Sep 11, 2012 18:52 |
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QuarkJets posted:That's correct, although I would guess that there's a much higher risk of an accident simply releasing a bunch of methane into the atmosphere, so it's a bit more hazardous than liquid carbon stores This is certainly an issue, since I don't think we have any real clue whether we can do it safely. The broader point I was trying to get at is that we're now introducing a huge new source of greenhouse gases from this nearly inexhaustible supply (wiki: "The worldwide amounts of carbon bound in gas hydrates is conservatively estimated to total twice the amount of carbon to be found in all known fossil fuels on Earth."), meaning that unless we get some breakthrough cheap technologies, we're not transitioning to carbon neutral energy sources anytime soon.
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# ? Sep 11, 2012 19:19 |
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marmot25 posted:This is certainly an issue, since I don't think we have any real clue whether we can do it safely. The broader point I was trying to get at is that we're now introducing a huge new source of greenhouse gases from this nearly inexhaustible supply (wiki: "The worldwide amounts of carbon bound in gas hydrates is conservatively estimated to total twice the amount of carbon to be found in all known fossil fuels on Earth."), meaning that unless we get some breakthrough cheap technologies, we're not transitioning to carbon neutral energy sources anytime soon. Oh, I know; even if we are able to effectively extract it, we're looking at pushing much more CO2 into the atmosphere than ever before, which is definitely the bigger problem. On the other hand, if we could safely resequester this carbon into a non-gaseous solution then that would definitely be the best scenario, because then we wouldn't have to worry about that methane being released randomly during a natural disaster
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# ? Sep 11, 2012 21:34 |
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Or we could just build some goddamned loving nuclear power plants that would immediately cut into CO2 production when they come online and we could spend more time making sure that the methane doesn't thaw and quite literally kill everyone.
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# ? Sep 11, 2012 21:53 |
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I thought there was some company who claimed they could use all that methane and such to partially replace petroleum for plastic production? Assuming that actually works, it'd be a better use than just burning it for fuel.
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# ? Sep 11, 2012 22:07 |
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Install Gentoo posted:I thought there was some company who claimed they could use all that methane and such to partially replace petroleum for plastic production? Assuming that actually works, it'd be a better use than just burning it for fuel. Yes, that's another good reason to wean ourselves off of burning oil for energy people sometimes overlook.
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# ? Sep 12, 2012 00:36 |
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Shipon posted:Yes, that's another good reason to wean ourselves off of burning oil for energy people sometimes overlook. My understanding was that gasoline and other oil products did not have any overlap in the refining process, by which I mean that per barrel you get X gallons of gasoline, Y pounds of plastic products, etc with relatively little variation in these quantities. So being able to make plastic from methane wouldn't change gas prices, but it would help with plastic production, which is important for its own sake QuarkJets fucked around with this message at 01:28 on Sep 12, 2012 |
# ? Sep 12, 2012 01:03 |
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In term's of localized power generation, has anyone looked up much on RTG ( Radioisotope thermoelectric generator) for domestic or small scales applications? Mars Curiosity RTG, 110W for 45kg total weight. I don't imagine that they would be any good for large scale operations (as for the most part they produce not much wattage at all with current tech, the ones used for space applications, such as the Curiosity mars rover, produce only a few hundred watts) but for small batteries and tiny loads they don't seem all that bad. In terms of energy though, these things are rocking, and with a bit of research for efficiency, they could be an awesome generator! Here's a few awesome things about them: - Run off the waste fuel from some nuclear reactors, that of Strontium 90, but you can still use other materials for this, many byproducts and waste. - Sr-90 has a half-life of 28.1 years, but using other fuels, like Plutonium-238 has a half-life of 87.7 years, or if you want long haul, Americium-241 with 432 years! - Using Sr-90 as an example, it produces around 0.96 Watts a gram - They aren't usable for weapon grade materials. - In most cases, they don't need too much shielding (according to Wiki, it needs around 3mm of lead shield, less or more depending on the fuel). - From what i can find, the cost is around $20 a gram for Sr-90, that is rather on the expensive side, but that is over a 30 year period just for half-life which I'd say is pretty darn good value. Obviously these things could never compare to a large scale reactor or peak load, but in terms of localized buildings like hospitals and all, put a nicely shielded one with some waste fuel, connect to batteries, and be kicking along for a very very long time. Personally, I don't see that as a huge cost, $20,000 for 1kW worth of fuel for 30 years? My main concerns are what would the sort of feasibility be for a generator like this? Most of the time they're used for space probes and missions (cause 80 year half life pretty drat good for fuel), but on the ground you could maintain and replace them without too much trouble I would think, not to mention upgrade them when needed or simply replace in a controlled way. I would totally put one in my backyard if it wasn't for NIMBYism. http://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator PDF of fuels and info: http://fti.neep.wisc.edu/neep602/SPRING00/lecture5.pdf
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# ? Sep 12, 2012 05:19 |
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I'm as much for nuclear power as the next guy, but putting radioactive waste and/or materials into peoples' homes seems like a bad idea. This is "dirty bomb" material. Also tracking all those radiation sources would be very difficult. You can't be sure it won't end up on some scrapheap somewhere sold as lead or whatever. The person stripping this thing likely will die. Everybody handling one of these with breached containment for extended periods of time will get a serious dose of radiation. The Soviet Union had a BUNCH of these generators which they used to power radio navigation beacons in remote areas like Siberia. They have lost track of a number of these after the dissolution of the USSR. A quote from Wikipedia: quote:In December 2001, three Georgian woodcutters stumbled over such a power generator and dragged it back to their camp site to use it as a heat source. Within hours they suffered from acute radiation sickness and sought hospital treatment. So, this is an idea I cannot get behind.
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# ? Sep 12, 2012 08:36 |
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schmen posted:In term's of localized power generation, has anyone looked up much on RTG ( Radioisotope thermoelectric generator) for domestic or small scales applications? This is just a small quibble, but it's not really as simple as that; what is the 1kW rated at, the beginning of the reactor's lifecycle, after 30 years, or is that the theoretical output in the scenario where we're able to transport nuclear waste products immediately from reactor to generator? Each day your generator will produce less power as the sample decays, which can be fine depending on how much power you need out of the generator and for how long. For a space probe/rover this kind of thing is perfect since you can only reasonably expect 10 years or so of operation before something else breaks anyway. For a hospital or something you just need to replace the generator every however many years. spankmeister posted:I'm as much for nuclear power as the next guy, but putting radioactive waste and/or materials into peoples' homes seems like a bad idea. This is "dirty bomb" material. Also tracking all those radiation sources would be very difficult. You can't be sure it won't end up on some scrapheap somewhere sold as lead or whatever. The person stripping this thing likely will die. Everybody handling one of these with breached containment for extended periods of time will get a serious dose of radiation. Dirty bombs are not a thing to be concerned about. No one who wants to build a bomb is going to build a dirty bomb, the entire concept makes no sense to anyone who takes a minute to understand the biological effects of radiation. Nuclear material record-keeping in the US is much better than in the USSR, and a hospital basement with well-marked warning signs is quite different from a radio navigation beacon in the middle of Siberia. I see no issue so long as the generator is marked and put it in a lead container with a warning engraved on the side. I wouldn't suggest putting these in homes QuarkJets fucked around with this message at 09:35 on Sep 12, 2012 |
# ? Sep 12, 2012 09:32 |
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QuarkJets posted:Dirty bombs are not a thing to be concerned about. No one who wants to build a bomb is going to build a dirty bomb, the entire concept makes no sense to anyone who takes a minute to understand the biological effects of radiation. quote:Nuclear material record-keeping in the US is much better than in the USSR, and a hospital basement with well-marked warning signs is quite different from a radio navigation beacon in the middle of Siberia. I see no issue so long as the generator is marked and put it in a lead container with a warning engraved on the side. I wouldn't suggest putting these in homes Good, then we are pretty much in agreement.
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# ? Sep 12, 2012 10:04 |
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quote:If you want to build "green households", then you should aim for the low-hanging fruit first: This? This is the low hanging fruit. Buy these. If you do not have 100% compact-fluorescent bulbs, go to Wal-Mart or Home Hardware or wherever you buy poo poo tomorrow and replace all of your bulbs. Yes, they are more expensive up front; they will pay for themselves (and then some) in reduced power consumption and increased lifespan, plus you'll be doing something stupidly easy while eliminating one of the biggest sources for household energy waste. ...If you have the extra money and want to really geek out, order some LED bulbs: Much more efficient, and they do not contain mercury (...Which reminds me: when your fluorescent bulbs burn-out, find a place that recycles them. Do not toss them in the trash. They contain mercury).
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# ? Sep 12, 2012 11:51 |
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20$/W means $60k for a 3kW... lasting 40 years,that's nearly 1mil kWh produced, for a value of $85k. Factor in capital costs and you're screwed, 40 years is pretty long. Probably still more feasible than solar energy which gets paid 0.27 to the kWh, though.
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# ? Sep 12, 2012 12:13 |
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spankmeister posted:Yes I should have been more clear about this but I did not mean to say that there is a huge risk of anyone turning these into a dirty bomb. (Well, some idiot might try anyway) but more that these materials can be quite dangerous and should be kept out of the hands of the general public. If you can make a dirty bomb you can also make a chemical bomb. The difference is the latter is much lighter, far less expensive, easier to infiltrate into places, and actually works terrifyingly well. A single nerve gas bomb could clear a quarter-square mile radius of all life in less than ten minutes. And there is very little anyone could do about it in such a situation.
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# ? Sep 12, 2012 13:06 |
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The Ender posted:
The LEDs do actually save you money though in the long run. Their price upfront is easily outweighed by the drastically lower electricity usage, and the far longer lifetime of the device before it "burns out" - even compared to CFL! The only problem with them ends up being is that they're usually in designs oriented to be used more like a spotlight or floodlight than a normal bulb pattern, but more normal lighting patterns have come out over time. Let's say you have an average 40 watt incandescent bulb you want to replace - it costs $1.25 for the bulb and runs for 1,000 hours. You can replace that with an 11 watt CFL bulb, that costs $7, and lasts 10,000 hours. Or you can replace that with a 6 watt LED bulb, that costs $23, but will last 50,000 hours. The current average electricity price in the US is 12.12 cents per kilowatt hour. Over the lifespan of the LED bulb, you'll use 300 kilowatt hours; so $59.36 for bulb plus electricity. To match that lifespan with CFL bulbs, you'd use 550 kilowatt hours and buy 5 bulbs; total comes to $101.66. With incandescent you'll use 2000 kilowatt hours and buy 50 bulbs; total comes to $304.90!
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# ? Sep 12, 2012 15:38 |
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schmen posted:My main concerns are what would the sort of feasibility be for a generator like this? Most of the time they're used for space probes and missions (cause 80 year half life pretty drat good for fuel), but on the ground you could maintain and replace them without too much trouble I would think, not to mention upgrade them when needed or simply replace in a controlled way. The availability of the fuel would be a roadblock to killowatt applications. In a very well-designed, extremely efficient breeder that could take something common like depleted uranium or thorium and fission all of it, you would expect at most 6.8% of your waste to be Sr-90 (http://en.wikipedia.org/wiki/Sr-90). And unlike Am-141 and Pu-238, you can't design a reactor to produce Sr-90 specifically. Am-241 and Pu-238 have their own issues as well. Pu-238 is extremely challenging to make with either U-235 or Pu-239 fuel cycles, while not so much with the Th-232 cycle which unfortunately nobody is using seriously. There's currently a shortage of Pu-238 which is one of the things keeping NASA from taking on projects that go beyond the asteroid belt. Pu-238 is a largely a relic of cold-war era nuclear materials breeding programs. Today it's a huge hassle to make more because it requires that we reprocess spent nuclear fuel for Np-237, which could technically also go into making a rather effective (highly pure) nuclear weapon (http://en.wikipedia.org/wiki/Pu-238). Am-241 is a decay product of Pu-241, half life 15 years. What doesn't help its case is the fact that Pu-241 is created in minute amounts on top of the fact that you need to let it age to get to Am-241. Ultimately the availability of these isotopes is going to depend on how many reactors we have and how we deal with our nuclear wastes. The US currently does not reprocess any of their waste outside of military applications, which severely limits them on the front of RTGs. You'll also have to strike a balance between having worth-while products and actually producing energy from your reactor. Designing a reactor for high transmutation ratio typically comes at the cost of being left with a reactor that doesn't so much make energy as it does hog it from other plants just to stay online. And there's also the possibility of just building a small modular reactor instead of a big RTG (http://en.wikipedia.org/wiki/Small_modular_reactor). You can't make battery-sized fission reactors (due to neutron flux issues) but you can still make them pretty darn small. Office Thug fucked around with this message at 16:37 on Sep 12, 2012 |
# ? Sep 12, 2012 16:31 |
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Install Gentoo posted:The LEDs do actually save you money though in the long run. Their price upfront is easily outweighed by the drastically lower electricity usage, and the far longer lifetime of the device before it "burns out" - even compared to CFL! The only problem with them ends up being is that they're usually in designs oriented to be used more like a spotlight or floodlight than a normal bulb pattern, but more normal lighting patterns have come out over time. I really want to emphasize the LED bulb love. If you can, get LEDs, the savings are better overall and you don't have to worry about disposal, so they're better in every way except for the slightly higher cost up front (and the difficulty of actually finding them). CFLs are just a transition technology
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# ? Sep 12, 2012 19:01 |
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Aureon posted:20$/W means $60k for a 3kW... It doesn't work like that; forty years later the generator will be producing much less power (unless the source has a long half life, but that requires a lot more fuel), so you get less energy overall than just (time)*(power on day one)
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# ? Sep 12, 2012 19:08 |
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QuarkJets posted:It doesn't work like that; forty years later the generator will be producing much less power (unless the source has a long half life, but that requires a lot more fuel), so you get less energy overall than just (time)*(power on day one) If the source has an half life of 28y, it's roughly offset by the inflation of energy prices.
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# ? Sep 12, 2012 20:21 |
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quote:I really want to emphasize the LED bulb love. If you can, get LEDs, the savings are better overall and you don't have to worry about disposal, so they're better in every way except for the slightly higher cost up front (and the difficulty of actually finding them). CFLs are just a transition technology Yeah, LEDs are the better option - I just talk about CFLs first because they are the most widely available alternative to incandescent bulbs for the moment. Are LEDs on any store shelves in America? In Canada they're strictly an 'order online' thing.
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# ? Sep 12, 2012 23:00 |
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The Ender posted:Yeah, LEDs are the better option - I just talk about CFLs first because they are the most widely available alternative to incandescent bulbs for the moment. Are LEDs on any store shelves in America? In Canada they're strictly an 'order online' thing. According to Home Depot's website I can pick them up in store now (although they won't ship them, oddly enough).
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# ? Sep 12, 2012 23:06 |
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The Ender posted:New bulbs Denmark (and some of the EU I'm not sure) banned import and sale of old style light bulbs meaning you can now boy only power saving compact-fluorescent bulbs or LED lights. America can do it as well, you just need to stop pussyfooting around the issues at hand.
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# ? Sep 12, 2012 23:17 |
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Boiled Water posted:
nope: quote:"The issue is too important to let it go away," said Rep. Joe Barton of Texas. "It is the perfect symbol of government over regulation and that is why we will continue to look for avenues to bring this bill up and ultimately repeal the de facto ban on traditional light bulbs."
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# ? Sep 12, 2012 23:20 |
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I stand corrected. What's the average life span of a traditional bulb? Because this seems like a problem that will eat itself.
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# ? Sep 12, 2012 23:32 |
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Beware of cheap LED bulbs (and cheap CFLs, but really crappy CFLs are harder to find these days) that may die quickly. Some of the teardowns of early LED bulbs revealed poor electronic and mechanical design along with crappy assembly techniques. More recent designs from major manufacturers are dealing with the heat from the LEDs much more effectively than earlier ones.
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# ? Sep 13, 2012 00:09 |
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The Ender posted:Yeah, LEDs are the better option - I just talk about CFLs first because they are the most widely available alternative to incandescent bulbs for the moment. Are LEDs on any store shelves in America? In Canada they're strictly an 'order online' thing. I've seen 'em on the shelves in Lowe's, Home Depot, Wal-Mart and Target in America. Probably other stores too, as well as get 'em on Amazon. Boiled Water posted:I stand corrected. Your standard incandescent light bulb is rated for 1000 hours, which means it'll work for a year if you use it for 2.75 hours a day roughly.
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# ? Sep 13, 2012 00:11 |
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I was a bit disappointed when I discovered that my parents had bought 500 incandescent bulbs right before the de facto ban on the old, inefficient style went through (they were worried about mercury in CFLs and didn't know about LEDs). I imagine that many Americans aren't aware of the existence and advantages of LEDs
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# ? Sep 13, 2012 01:12 |
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QuarkJets posted:I was a bit disappointed when I discovered that my parents had bought 500 incandescent bulbs right before the de facto ban on the old, inefficient style went through (they were worried about mercury in CFLs and didn't know about LEDs). I imagine that many Americans aren't aware of the existence and advantages of LEDs They're betting on a resurgence of the easy bake oven.
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# ? Sep 13, 2012 02:13 |
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# ? May 9, 2024 23:58 |
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Office Thug posted:Stuff about fuel availability and small modular reactors Ah thanks very much for that, I'm actually not all that educated about the waste and all of nuclear reactors, I knew wasn't easy to get all the isotopes, but wasn't aware that it was such a pain to get it in the first place. Thanks for that link too, those SMR's look pretty nice for a reactor design, plus I'm sure it would be a lot easier having one of those than a few hundreds to thousands RTGs all scattered around I guess I just like the idea of having a reactor where you don't have to fuel it for decades, instead of lovely coal like Australia has way too much of right now.
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# ? Sep 13, 2012 02:56 |