Well, Asguard's question is a bit nuanced. But the answer is no, it doesn't work like that. Solar cells work using the photo-electric effect. You can think of it as using a bullet to knock an apple off of a tree. If the bullet is too slow (i.e. you throwing it), it won't have enough energy to make the apple fall. However, if you give the bullet enough energy, it will knock the apple out of the tree. Photons from the sun hit the surface of a solar cell, and if there is enough energy, the photon knocks an electron out of its place in a non-conducting band into a conducting band. This gives a current (electrons moving = current). But it takes a lot of energy to knock electrons out of their place. For photons, energy goes like 1/wavelength, which means longer wavelength photons have less energy. But it is precisely the long wavelength photons that are responsible for heating the earth (IR radiation). Solar cells use visible light---this is just good design, as visible light has the highest intensity from the sun. Either way, Search & Destroy doesn't know what (s)he is talking about.
To clarify: Long wavelength photons are responsible for heating the earth, and short wavelength photons are the photons that solar cells use. I was a bit confused, because the solar cells can absorb the long wavelength photons. But this is resolved because they don't absorb any more or less of the long wavelength photons than, presumably, the ground they're sitting on.
I wouldn't of said it was "dead dinosaurs". I would actually suggest that it was millions of years worth of decaying plankton (protezoa & Algae). This is one of the main reasons that OilisMastery's comments rarely found much more form than blatent woo-wooism, as he would have everyone believe that it just exists as a chemical formulated naturally without the need of life. (I don't deny it's possible to "fabricate through process" oil, it's just for it to naturally be produced without refinement is ridiculous).
BenTheMan, is that all of the solor generators though? some of them work by heat, ie they heat a vat of concreate (or whatever its made of) which is used to make steam which turns a turbine. Solor heating is the same except that it heats water. Inzomnia, i do realise that but the biggest risk isnt CO2 its water. if enough water turns to vapor and sits in the atmosphear we have a real problem which cant be solved by simply dialing down CO2 emmissions and planting more trees. If you can reduce the surface heat (by using up that heat to produce energy for instance) then you have less steam and there for less H2O in the atmosphear. It might not work that way but i couldnt understand why it wouldnt
Hi and thanks for that luckily I'm flame retardant lol. But seriously I think you are missing a crucial point. Solar cells are being built out of different materials thus have different 'band gaps.' For instance a multi-junction cell can efficiently interact and transform different wavelengths. In theory the notion of shooting an apple can be tweaked to a wide enough diversity of wavelengths and mass-produced to counteract global warming. This won't happen don't worry I'm not saying that. I'm just saying it is possible. And to clear one thing up - are the photons that heat up our earth subject to the 'photo-electric' effect?
Inasmuch as I understand it, most solar cells work via the photo-electric effect. I haven't heard of the types of setups you're talking about. If you think about it, using visible light makes the most sense. The greatest intesity of solar radiation coming from the sun is in the visible band of the EM spectrum. This is precisely why the band is called ``visible''---our eyes evolved in the most efficient way possible, utilizing the brightest part of solar radiation. I may be missing something, and if you can provide some sort of evidence that other designs are being used, I will happily concede the point. However, it makes no sense to me that one would design a solar cell to operate on such low intensity, low energy photons coming from the sun. I don't know what this means. Do you mean ``Can IR photons knock electrons off of metals?'' The answer is probably yes, if the electrons were bound loosely enough to the metal. Probably you'd have a hard time finding such materials, but I don't know. If you can show me where people have designed an IR solar panel for large scale use, then please do. I think they would be very inefficient, for reasons listed above.
Another point I'd like to raise: I think labeling IR as an unproductive energy source intuitively contradicts your other notion that IR accounts for most of earth's warming. Depending on my terms, I could say IR accounts for half of the energy coming into earth from the sun. --- And here is an example of primitive, but existing IR panels: http://sparkingtech.com/tech/new-infrared-solar-panels-work-even-at-night/ As Asguards question was theoretical, so was my answer. We have the potential to capture all of the sun's energy with solar panels.
ben, they are used to provide base line power because they can store heat for 24 hours. there for they can keep producing power at night. they were designed by a proffessor at a NSW uni but our gov wasnt intrested so it was sold to a US company
Oil is composed of aliphatic molecules of fully saturated carbon chains. They are chemically very simple and maximally reduced. When you burn them, they oxidize and from water and carbon dioxide.
Any electricity that we produce will probably ultimately end up being used to heat up the planet anyway.
But, Asguard, water vapor isn't considered as major concern (or is it..??), because as I understand it, there is an uncontrollable phenomena that regulates its level, i.e. when the water vapor content in atmosphere increase, the rainfall simply increase, too, so the water vapor decrease again. Here (link) is a bit explanation and here is the profile of global relative humidity for past decades (taken from that link), water vapor is likely decreasing: Please Register or Log in to view the hidden image! An excerpt from that link: This graph shows that the relative humidity has been dropping, especially at higher elevations allowing more heat to escape to space. The curve labelled 300 mb is at about 9 km altitude, which is in the middle of the predicted (but missing) tropical troposphere hot-spot. This is the critical elevation as this is where radiation can start to escape without being recaptured. The average relative humidity at this altitude has declined by 20% (or 9.4 percentiles) from 1948 to 2008! CO2 concentration, on the other hand (the green line), is steadily increasing, as a result of anthropogenic activities: Please Register or Log in to view the hidden image! But there are clean energy (such as photovoltaic) and, uhm, dirty energy (?Please Register or Log in to view the hidden image!). "Dirty" energy such as fossil fuel produces CO2 as by product, and the CO2 blocks the heat that suppose can be escaped out of atmosphere.
Yes, I know, I was responding to his question about whether or not capturing solar radiation and converting its energy into electricity would lower global temperatures due to the solar radiation being turned into electricity rather than heat. Any electricity we generate will probably end up as waste heat anyway.
I see what you mean. Yea, in that case, in which the earth is like a closed system, it does not matter how the heat is distributed, it's still stored within earth.
No, it doesn't. 49% of the heat on earth comes from IR radiation directly from the sun. The rest of the heat is caused by visible light which is absorbed and re-emitted in the IR band. You can always define ``your terms'' in such a way that makes you right. Source? To what extent is this ``waste heat'' responsible for warming the earth?
I'm sorry but I still don't understand why it's theoretically impossible to efficiently capture IR. Please explain it in a nice, specific paragraph. I will spend my time reading it if you spend time writing it.
I never said it was impossible, I just said that it didn't make sense. Asguard pointed out that there were solar cells designed to work with IR radiation. The point I was making is that most solar cells run on visible light, and most solar technology in the future will also run on visible light. So solar-cell-induced global cooling is probably never going to be an issue, even if we covered the surface of the earth in solar cells. This, coupled with the fact that most of the warming (51%) of the earth happens when ambient light is reflected and absorbed, and then re-emitted as IR radiation---solar cells reflect a good deal of light (i.e. they'll never be 100% efficient at capturing radiation). So, again, global cooling will never be a problem.
I agree. It's possible but it's not going to happen. I would bet my life on it. I know we are on the same page. I'm drunk. Thank you for the conversation and hopefully you won't judge me so drastically next time. I'm a human, not some piece of matter for you to call names. Ahhhh goodnight
