Re: Harvesting the Sun... on the cheap
Very interesting Jones. 8-) As far as the 2nd Law is concerned it's always struck me that to show it's wrong is a no-brainer. All one needs is a chess board and a concept of scale. In the classic case of the steam engine where disorder on the micro-scale is increased, people totally forget that order on the macro-scale is increased. They ignore the fact that the engine has taken Sir Joseph Porter, together with his Sisters, his Cousins, his Aunts down to H.M.S.Pinafore at Portsmouth. In short they have a thoroughly blinkered view of order. The concentrate on the fact that the glass is half empty and fail to see that it is also half full. Cheers, Grimer At 02:43 pm 08-02-05 -0800, Jones wrote wrote: Hindsight is 20/20 as they say. I hope the lab execs at Sandia do not have to find that out the hard way... if it turns out that they dropped funding on a particularly promising project... or if some ploy was involved to keep Sam out of the IP picture. The Sunflower solar-mirror story mentined in FSB (in another post today) brings an enabling technology to mind (not mentioned in that story) which even dispenses with the need for solar cells, per se. It involves both conversion of heat to electricity and the violation of Plank's Law of blackbody radiation. That's right, the violation of Plank's Law of blackbody radiation. Yet, does anyone on vortex remember the photolattice? Why it raised so little curiosity at the time is a huge mystery. Did it slip though the lattice G If Plank got a Nobel for discovering an over-reaching law, shouldn't the iconoclasts get at least some tiny bit of recognition? Looking back over files and scientific announcements relevant to LENR, solar energy and/or greatly increased efficiency in energy-conversion over the last few years - this one keeps recurring in importance: For one thing - because it could fit into so many other schemes - particularly thermal solar conversion or LENR heat conversion. Solar thermal is the easiest of all forms of free energy to harvest (with mirrors) and a factor of 10-50 times less costly than using solar cells - but all you normally get for the low cost is day-time heat - not electricity, and not particularly high-grade heat at that. What the photolattice does is to convert low grade heat into coherent IR light, and very efficiently. Coherency is the key to efficiency. When trying to rate a wide range of enabling technologies in terms of unrealized potential, the newsbyte that seems now to have had the greatest easily-realizable potential, to a wide swath of alternative energy research could be this technology of the photolattice but has the technology now gone stagnant? I wish someone at Sandia or Stanford could answer that one. Here is the reference: A Novel Photolattice with Extraordinary Properties By Neil Savage http://www.spectrum.ieee.org/WEBONLY/wonews/oct03/1003phot.html A device from Sandia emits infrared radiation at a fixed wavelength and with a conversion efficiency that appears to defy Plancks law Notice how the editors downplay the part about Plancks law - don't want to offend anyone, right? Eventually, the high-priests of the physics establisment will also find a way to save-face on this Law, of course, just as with the soon-to-be-demolished 2nd Law. N. Savage is not so diplomatic in the story: 15 October 2003A microscopic device built by researchers at Sandia National Laboratory (Albuquerque, N.M.) could lead to better photovoltaic cells, more efficient light bulbs, and the rewriting of basic physics texts. Researchers Shawn Lin and James Fleming built a photonic lattice that emits infrared radiation only at a specific wavelength. The lattice is a type of photonic band gap crystal, in which a regular structure at the scale of microns or nanometers allows light to exist only at specific wavelengths With the same photolithographic methods used to manufacture computer chips, the scientists inscribed the structure they wanted in silicon. They then filled the gaps with tungsten, the same material that makes light bulb filaments, and etched away the silicon, leaving a three-dimensional waffle of tungsten rods, piled in a crisscrossing log cabin style. The size and spacing of the rods, half a micron thick and spaced 1.5 µ m apart, force the photons passing between them to fit into particular wavelengths. [OK they used the expensive technique of photolithography to discover and document the process, but that does not mean that bulk process cannot be adapted to manufacture it] When Lin and Fleming heated the device in a vacuum to 1250 °C, the typical operating temperature of a thermal photovoltaic (PV) cell, they saw a sharp emission peak at 1.5 µ m. They calculated that the peak would translate into an optical-to-electrical conversion efficiency in a PV cell of approximately 34 percent and an electrical power output of about 14 W/cm2. Thats far greater than the 11 percent
Harvesting the Sun... on the cheap
Hindsight is 20/20 as they say. I hope the lab execs at Sandia do not have to find that out the hard way... if it turns out that they dropped funding on a particularly promising project... or if some ploy was involved to keep Sam out of the IP picture. The Sunflower solar-mirror story mentined in FSB (in another post today) brings an enabling technology to mind (not mentioned in that story) which even dispenses with the need for solar cells, per se. It involves both conversion of heat to electricity and the violation of Plank's Law of blackbody radiation. That's right, the violation of Plank's Law of blackbody radiation. Yet, does anyone on vortex remember the photolattice? Why it raised so little curiosity at the time is a huge mystery. Did it slip though the lattice G If Plank got a Nobel for discovering an over-reaching law, shouldn't the iconoclasts get at least some tiny bit of recognition? Looking back over files and scientific announcements relevant to LENR, solar energy and/or greatly increased efficiency in energy-conversion over the last few years - this one keeps recurring in importance: For one thing - because it could fit into so many other schemes - particularly thermal solar conversion or LENR heat conversion. Solar thermal is the easiest of all forms of free energy to harvest (with mirrors) and a factor of 10-50 times less costly than using solar cells - but all you normally get for the low cost is day-time heat - not electricity, and not particularly high-grade heat at that. What the photolattice does is to convert low grade heat into coherent IR light, and very efficiently. Coherency is the key to efficiency. When trying to rate a wide range of enabling technologies in terms of unrealized potential, the newsbyte that seems now to have had the greatest easily-realizable potential, to a wide swath of alternative energy research could be this technology of the photolattice but has the technology now gone stagnant? I wish someone at Sandia or Stanford could answer that one. Here is the reference: A Novel Photolattice with Extraordinary Properties By Neil Savage http://www.spectrum.ieee.org/WEBONLY/wonews/oct03/1003phot.html A device from Sandia emits infrared radiation at a fixed wavelength and with a conversion efficiency that appears to defy Plancks law Notice how the editors downplay the part about Plancks law - don't want to offend anyone, right? Eventually, the high-priests of the physics establisment will also find a way to save-face on this Law, of course, just as with the soon-to-be-demolished 2nd Law. N. Savage is not so diplomatic in the story: 15 October 2003A microscopic device built by researchers at Sandia National Laboratory (Albuquerque, N.M.) could lead to better photovoltaic cells, more efficient light bulbs, and the rewriting of basic physics texts. Researchers Shawn Lin and James Fleming built a photonic lattice that emits infrared radiation only at a specific wavelength. The lattice is a type of photonic band gap crystal, in which a regular structure at the scale of microns or nanometers allows light to exist only at specific wavelengths With the same photolithographic methods used to manufacture computer chips, the scientists inscribed the structure they wanted in silicon. They then filled the gaps with tungsten, the same material that makes light bulb filaments, and etched away the silicon, leaving a three-dimensional waffle of tungsten rods, piled in a crisscrossing log cabin style. The size and spacing of the rods, half a micron thick and spaced 1.5 µ m apart, force the photons passing between them to fit into particular wavelengths. [OK they used the expensive technique of photolithography to discover and document the process, but that does not mean that bulk process cannot be adapted to manufacture it] When Lin and Fleming heated the device in a vacuum to 1250 °C, the typical operating temperature of a thermal photovoltaic (PV) cell, they saw a sharp emission peak at 1.5 µ m. They calculated that the peak would translate into an optical-to-electrical conversion efficiency in a PV cell of approximately 34 percent and an electrical power output of about 14 W/cm2. Thats far greater than the 11 percent efficiency and 3 W/cm2 output predicted by Max Plancks Law of Blackbody Cavity Radiation. END Yes and at least one expert who commented on this back then says that 34% - which is much better than an auto engine, for instance, is an understatement. There is no reason why coherent radiation should not convert at double that... yet... Did this great unrelaized potential fall under the Sandia budget axe, or what about the photonics group at Stanford ( i.e. the Fan club)? Maybe they are just slyly waiting to try to get it into the hands of free enterprise and out of government IP control. Who knows? Enquiring minds do want to know...BTW I have written Dr. Fan for an update, but I am not really expecting to get past his
Re: Harvesting the Sun... on the cheap
Jones wrote about collecting sunlight with mirrors and a device that when heated emitted coherent IR light, whihc could be converted to electricity by a PV cell with good efficiency. The caveats: You have to look at the whole system costs and maintenance. Solar concentrators are old stuff, they pour lots of light onto chips, making good use of their efficiency and cost. The mirrors have to be solar trackers with attendant system costs and have to be kept clean. There are clever afocal concentrator designs which do not have to be tracked and have good collection efficiencies, but they are cup-like and could fill with dust, sand, snow. There is no simple tradeoff if you want to collect lots of energy, not just niche applications. This is not simple. Mike Carrell
