Bouncing Light Around Between Electrons and Holes

Dean Sigler Hydrogen Fuel, Solar Power, Sustainable Aviation 0 Comments

Bob Elliott of the comedy team Bob and Ray died February 3, reminding your editor of one of the many routines Elliott and Ray Goulding performed on live radio.  It involved an inventor who had perfected a solar panel that could run the lights in your house all day, but couldn’t keep them going at night when they were really needed.  That was over 50 years ago, and investigators at the Pacific Northwest National Laboratory, Argonne National Laboratory, SuperSTEM, and the University of Oxford have come up with a possible solution to Bob and Ray’s quandary. Combining two oxides, one containing strontium and titanium (SrTiO3) and the other lanthanum and chromium (LaCrO3), they came up with a material that uses the interface …

Solar Impulse Passes Midway Islands

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

With the sun soon to rise in the Pacific, Solar Impulse 2 continues scooting at over 60 mph toward Honolulu as the third night comes to an end.  Significantly, Andre’ Borschberg and the 747-size plane have made it past the Midway Islands, once a stop-over for Pan-Am Boeing 314 “China Clippers.”  Even with their 3,500-mile range, those luxurious planes needed a fueling stop mid-way between Hawaii and China or Guam. The islands were important enough as a way station in the vast Pacific that one of the largest and most decisive battles of World War II took place near them.   In a battle terrible destructive to both sides, U. S. forces sank four Japanese carriers, essentially casting the fate of …

Layering Astonishingly Light Materials to Make Electricity from Light

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Researchers at the Vienna University of Technology have combined two semiconductor materials, each only three atomic layers thick. Adding one semiconducting layer of the photoactive crystal tungsten diselenide to a layer of molybdenum disulphide, and “creating a designer-material that may be used in future low-cost solar cells.” Having worked with graphene, that two-dimensional, atom-thick material that promises much for structures, batteries and solar cells, Thomas Mueuller, assistant professor of photonics, and his team “acquired the necessary know-how to handle, analyze and improve ultra-thin layers by working with graphene.”  The team applied their lessons learned with graphene to combining two ultra-thin semiconductor layers and are now studying their optoelectronic properties. Mueller explains, ““Quite often, two-dimensional crystals have electronic properties that are …

Ohio State’s Solar-Air Potassium Battery

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Ohio State University researchers have come up with a two-in-one solar cell/battery combination that promises great efficiency and low costs.  What’s not to like? Unfortunately for readers of the blog, it’s initially only a stationary system that will make energy storage a viable circumstance for large power plants, but it seems that the technology could be adapted to lighter, portable applications, such as electric vehicles. Ohio State is keeping somewhat mum about the patent-pending device, which they are developing as a commercial entity under the auspices of their spin-off, Kair (K for potassium, plus air and pronounced “care”).  We’ve heard a great deal about upcoming lithium-air batteries, but potassium-air is unique.  Even more unique, this battery stores energy from its …

Trapping Light: A “Perfect” Solar Absorber?

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

The news item from David L. Chandler at the Massachusetts Institute of Technology (MIT) claims that researchers there have come close to realizing the “ideal” for solar absorption, trapping and containing all of light’s wavelengths that reach earth’s surface from the sun.  This absorbed sunlight is converted to heat by a two-dimensional metallic dialectric photonic crystal, which can absorb sunlight from a wide range of angles and withstand extremely high temperatures.  Even better, it can be made cheaply and in large quantities, according to MIT. One aspect of the design that might make it difficult to use on aircraft is its high operating temperature.  A solar-thermophotovoltaic (STVP) device, the energy from the sunlight hitting the cells is “first converted to …

EAS VIII: Across the Atlantic – Twice

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Jean-Luc Soullier, holder of Fédération Aéronautique Internationale records for speed and altitude in an aircraft almost lighter than its pilot, has a greater series of ambitions to expand the range and speed of electric aircraft. Having stretched the limits of his Colomban MC-30e with two different motors, he’s looking at a longer-spanned, cleaner aircraft – the Windward Performance Duckhawk – as a means of getting higher speed and much longer range for a truly formidable (tres formidable) crossing of the Atlantic Ocean, not once, but twice. The airplane, with a Rotex motor on the nose and a specially-designed Arplast three-bladed propeller, will weigh a mere 105 kilograms (231 pounds) empty – without batteries. This is considerably less than the lightest …

Solar Impulse 2 Ready to Take on the World

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Even while the first Solar Impulse was scaling the Alps, traversing the Moroccan desert, and crossing America, skilled craftsmen and women were designing and building Solar Impulse 2, a larger, heavier solar-powered airplane rolled out this week.  Its next challenge, that of flying around the world, will test the limits of even this seasoned team. As shown on the first Solar Impulse’s flights, “Flying the Solar Impulse aircraft is quite different from being at the commands of any other airplane. Flight tactics, piloting skills, aerodynamics had to be re-learned from scratch.”  Part of the difference comes from the aircraft’s huge size and light weight.  Solar Impulse shares this:  “Here’s a fun fact for you to understand how special this aircraft is: …

Solar Cells a Few Atoms Thick

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Researchers at the Vienna University of Technology have come up with a way to create one-atom thick, flexible, semi-transparent solar cells.  Instead of the graphene often touted as a means toward such an end, however, the scientists have turned to atom-thick layers of tungsten diselenide for their wonder material. Experiments show that ultrathin layers of tungsten and selenium may have properties that would make them applicable even to electric aircraft use – if they can capture a significant amount of energy – or at least as much as thin-film silicon cells can. Graphene has been a popular favorite since its Russian “discoverers” were awarded the Nobel Prize in physics in 2010.  One of the strongest materials, graphene can manage stresses …

Solar Cells Collect More Light, Display Art

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Friend and frequent contributor Colin Rush sent this Economist item about Semprius, a concentrating solar cell maker about to go into production with their highly efficient technology. It’s big news that a production solar panel is able to convert 42.5 percent of sunlight falling on it into energy, when the world’s record for any solar cell was set last September by the German Fraunhofer Institute for Solar Energy Systems with an experimental multi-junction solar cell that’s 44.7 percent efficient.  The 42.5 percent for Semprius cells drops to about 35 percent when they are surrounded by the normal mounting flanges and connecting lines – still well above most production panels. These may achieve 50 percent with suitable refinement. Using breakthroughs devised …

5X Batteries? How About 70,000X Solar Cells?

Dean Sigler Electric Powerplants, Sustainable Aviation 2 Comments

Matt Shipman of North Carolina State University News Services reports on a connector that could allow stacking solar cells without losing voltage.  This stacking could allow cells to operate at solar concentrations of “70,000 suns worth of energy without losing much voltage as ‘wasted energy’ or heat.”  This could have tremendous implications improving the overall efficiency of solar energy devices and reducing the cost of solar energy production. Stacked solar cells live up to their name, simply being several cells stacked on one another, with their layering leading to up to 45-percent efficiency in converting solar energy into electricity.  So far, the big drawback has been the junctions between cells, which tend to waste the energy from the connected cells as …