Comments for Nano-Antennas for Solar, Lighting, and Climate Control at http://www.ecogeek.org , comment 1 to 26 out of 20 comments http://www.ecogeek.org Sat, 18 May 2013 23:27:54 +0100 FeedCreator 1.7.3 http://www.ecogeek.org/solar-power/1357#comment-45925 Today you can not straighten out the high frequencies, but can be given through the active electrical resistance heat, which absorbs nanoantenna. Obtain an analog of the thermoelectric Peltier element, but much cheaper. - Dmitry Zimnitsky Thu, 01 Mar 2012 07:59:57 +0100 http://www.ecogeek.org/solar-power/1357#comment-41766 Carbon Man, These actually could cool a room under certain cercumstances. It's not that mysterious. The reason is that Novack is not talking about getting useful energy at equilibrium from a room but getting energy out when a room deviates from equalibrium. Say your walls are coated with nanoantenna's at some fixed temperature like 69 F. Say you now have a party and the room temperatures rises. The walls act as a heat sink shunting the excess heat away. No different than if the walls were a large thermal mass at 69 F and the room air temp shot up to 80F, the walls eventually shunt away the excess heat. In fact I think the walls coated with these antenna's would keep the heat from building up because they wuold be a sink for excess heat in the air. In that sense, they do not *cool* a room as much as keep a room from getting hot. There is a difference. So, while I agree with you that technically these antenna's if at equilibrium with the environment would not work, the practical uses are in situations not in equilibrium. - Bob21 Thu, 11 Nov 2010 18:23:22 +0100 http://www.ecogeek.org/solar-power/1357#comment-41380 Heat engines require a temperature difference. The Carnot limit is a quantitative formula that gives the amount of useful energy that can be extracted from the hot object (the unused energy goes into the cold object). The higher the ratio in absolute temperatures, the higher the efficiency. This law does not apply to "ordered" energy such as coherent microwaves from an antenna or macroscopic mechanical motion. It does apply to (nearly) thermal radiators such the sun, earth, walls, etc. The sun is so hot that 90-95% of energy can be extracted in theory. No useful energy can be extracted from a room at a uniform temperature, just as a glass of water does not spontaneously turn into ice and steam. Any attempt to create a temperature difference (i.e. refrigerating the nantenna) will take more energy than it will generate. However, solarcells and airconditioners are about 1/3 as efficient compared to these thermodynamic limits, and expensive. There is vast room for improvement here. No laws of physics need to be harmed in the making of this revolution! - carbon man Sun, 03 Oct 2010 15:31:00 +0100 http://www.ecogeek.org/solar-power/1357#comment-41002 The next tricky bit is the rectifier to get down to dc. Only cheap solution looks to be MIM diodes. Would be good to see a breakthrough there. - Steve Hall Wed, 01 Sep 2010 10:50:47 +0100 http://www.ecogeek.org/solar-power/1357#comment-38394 The 2nd law says that for ANY process the entropy of the universe must increase. Where is the increase in their hypothetical system? With antennas one can capture some energy from low entropy coherent radiation (microwave, radio, laser, etc.) but not from high entropy black body radiation. This was a futile exercise. - R. Frist Wed, 07 Apr 2010 18:49:11 +0100 http://www.ecogeek.org/solar-power/1357#comment-38245 I believe that there is no violation of the 2nd law in having an antenna pick up IR. If antenna's did not work for IR they would not work for cell phones or radio either and the wavelengths in those are far less energetic than IR at 10 microns. Regarding the antenna in the snow, well the earth does emit a huge amount of IR at an almost constant rate which varies slightly over the year and is between 300 to 400 W/m^2 most of the year in the midwest. This is just the release of absorbed solar energy which has to be since the earth is in equilibrium or it heats up like Venus. So, I believe you could pull energy from the re-radiated IR and heat your house in the winter just as you can heat your house from the sun during the day. In fact you are just using converted, downshifted re-radiated solar energy. The confusion comes in when one thinks the air temperature has any relation to getting IR energy in the antenna- since it feels cold out at night in the winter how can there possibly be a lot of energy? I think the answer is that the IR waves pass through the air without heating it too much so you don't notice it. Regarding the reusing the same energy over and over again, that would work for a while as you reused some waste heat but you would eventually run up against the the increase in entropy which would make the energy useless but since the earth, compared to your house, is essentially an infinite size black body which radiates, I think you could heat your house at least through the winter. :) - Bob21 Thu, 01 Apr 2010 19:30:05 +0100 http://www.ecogeek.org/solar-power/1357#comment-37202 I wonder if this technology could be applied to the cool end of a Stirling engine and reduce the size of the cooling components. - Bill Fri, 12 Mar 2010 12:59:20 +0100 http://www.ecogeek.org/solar-power/1357#comment-32906 If they succeed in getting this system to work think how strange things would be. Everything at temperatures over absolute zero emits some black body infrared radiation. In the winter just put some of these magic antennas outside in the snow and use the power to run an electric space heater in the house. It would usher in a new world with new physical laws. You would be able to use the same energy over an over, heat to electricity and back to heat after turning a motor or lighting a lamp. - R. Frist Mon, 30 Nov 2009 18:45:37 +0100 http://www.ecogeek.org/solar-power/1357#comment-28983 I feel the nano techology have to be supported more by getting it's possible contributions out to the public via radio, TV, magazines etc. I have contacted Nova Science Now to do a program about this technology. The more press, and the more people hear about the different potential applications for this technology, hopefully funding for fast tracking this technology will occur which will help get it to market in a cost effective timely manner. - Tom Thu, 30 Jul 2009 22:43:16 +0100 http://www.ecogeek.org/solar-power/1357#comment-26919 If such a device could work one could use it to transfer energy from one body to another even if both started at the same temperature and were both in an insulated box. This does not happen in our universe. How did they get funding for this project? Maybe its a cover for some sort of stealth technology. - Ramsey Frist Sat, 16 May 2009 10:25:15 +0100 http://www.ecogeek.org/solar-power/1357#comment-22055 sorry here it is :-\ http://www.inl.gov/pdfs/nantenna.pdf - Stefano Mon, 15 Dec 2008 11:20:19 +0100 http://www.ecogeek.org/solar-power/1357#comment-22054 Here is the link to original paper ;D http://www.inl.gov/pdfs/nanoantennas_science.pdf - Stefano Mon, 15 Dec 2008 11:18:16 +0100 http://www.ecogeek.org/solar-power/1357#comment-21930 I just hope in what I read. It would be a living dream on Earth - Stefano Fri, 12 Dec 2008 04:11:07 +0100 http://www.ecogeek.org/solar-power/1357#comment-20224 It is always appropriate to take a skeptical position...but it seems that this concept and the basis for it is widely known. Radio antennnas are no leap of faith. The potential efficiencies are also probably well known...and no doubt do not violate any laws of thermodynamics. I am generally a skeptic...but this idea seems to make sense to me. The problem with generating useful electricity from it, for example, is far from solved. But perhaps the heat transfer applications are much easier to solve - I don't know. And, no doubt, this work is going on in many places, as implied in parts of the original article. I doubt that U of Idaho or anyone is taking exclusive credit for it. They may have made some progress in making it practical...and that is what they seem to be claiming. - boband Sat, 25 Oct 2008 09:37:56 +0100 http://www.ecogeek.org/solar-power/1357#comment-15406 First off, he isn't a DR... he doesn't have a PhD - he has a Masters in Environmental Engineering. Did you ask if he can verify the existence of the nano antennas on that piece of gold sheet? He'd be lying if he says he can. Oh, and that nice image of the spiral antennas is courtesy of Univ. of Central Florida - it was THEIR work, not the lab's. Lastly, any real scientist would tell you that this is so far-fetched it is crazy AND it helps if you don't steal your colleague's ideas and life work in the process to create a name and buck for yourself, Dr. Novack! - Katmandu Fri, 27 Jun 2008 16:04:05 +0100 http://www.ecogeek.org/solar-power/1357#comment-14604 At Idaho National Laboratory we have produced a video on the solar nanoantenna technology. You can view it at: http://www.youtube.com/watch?v=9fuofnZM5eE - Sara Prentice Wed, 11 Jun 2008 09:02:29 +0100 http://www.ecogeek.org/solar-power/1357#comment-12423 I'd also like to thank Dr. Steven Novack at the Idaho National Laboratory and colleagues for making such a tremendous breakthrough!!!! Thankyou Hank chief geek for bringing us this incredible piece of news!!!! Love you both for both of your contributions to a better/smarter world! :) - Rosa R. Sat, 26 Apr 2008 00:20:34 +0100 http://www.ecogeek.org/solar-power/1357#comment-12422 I found this site today (April 26, 2008-Sat) by accidentally stumbling upon Yahoo!Green a few days ago! This is a very cool site! Thankyou Hank!! Great stories!!! and links! -Rosa (always a fan of the environment and making sure I take it upon myself to learn more and more, and be able to use that knowledge for the better!) - Rosa R. Sat, 26 Apr 2008 00:12:50 +0100 http://www.ecogeek.org/solar-power/1357#comment-9864 Geez, what a horrid bit i left above. I do insist none the less, that this subject seems a wonder filled learning/teaching vehicle. In defense of my crappy bit above: Emphasis was on the Imagining, just for the hope of jogging someone into a better idea. Thanks for the free platform! Davie - davie Wed, 13 Feb 2008 03:22:08 +0100 http://www.ecogeek.org/solar-power/1357#comment-9818 Hello Hank Green and All Others, I came to your article via jb's sustainabledesignupdate website, thanks, John Barrie! Having read and reread Farrington Daniels's book: Direct Use of the Sun's Energy, Revised 1974 many times, my first impression upon reading Hank Green's Ecogeek piece was : selective radiation coatings times quantum leap, then, as reading proceeded, it all reminded me of the heatpipe first encountered in Sci.Amer.magazine. A nanoscale heatpipe would have a minimum size of pipe sufficiently large to accomodate the requirements of the given working fluid which must pass through a transition from a vapor state to a liquid state and travel the length of the pipe by capillary action to complete a working cycle by being vaporized again by the heat input and passing the length of the pipe again, in the opposite direction, as a molecule of vapor at molecular speed. A heatpipe is able to conduct heat the length of the pipe at a far greater efficiency than the best of solid conductors. What I imagined is that the nantenna is accomplishing a transfer and transformation of energy utilizing electrons in a role like a working fluid plays in a heat pipe, in so far as it goes between the recieving and emitting ends of the system. This might be wrong: the nantenna might be imagined as a single molecule that accepts the energy of electromagnetic energy on one end and emits a ray of some nearly equivalent or less energy out the other end--that is, without electrons flowing through some intermediary conducting medium. Of course the imaginable possibility exists that nantennas require some conveyance between the receiving and emitting which could be some plasma stuff like solar wind in a magnetic field,for all I do not know. All I really know is that sixty cents U.S. times 2 sq.ft. worth of gold with the possibility of substiting other metals albeit no doubt with trade-offable efficiencies, rings like an economically viable proposition to me. I for one will be trecking along the links and references to be learning more...the "mind blowing" as someone upstream put it, possibilities at least for sci fi are right there fo sho. Well, also, the Hank Green piece is getting a second read here now... if you will excuse me, presently adding a new favorite.. davie - davie Tue, 12 Feb 2008 02:27:24 +0100