Solar Cells and Artificial Photosynthesis Make Hydrogen Directly

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Science 2.0.com reports on an exciting potential breakthrough in solar energy and its direct transformation into hydrogen fuel.  Usually, solar cells generate current from photons, making electricity which can run things or be stored in batteries. This new and different approach, using an innovative and inexpensive solar cell and a metal oxide photo anode, can store nearly five percent of solar energy chemically as hydrogen. The metal oxide bismuth vanadate (BiVO4) photo anode includes a small dose of tungsten atoms, was then sprayed onto conducting glass and “coated with an inexpensive cobalt phosphate catalyst,” which helped speed up oxygen formation during water splitting. Science 2.0 reports Professor Dr. Roel van de Krol’s remarks.  He’s head of the Helmholtz Zentrum Berlin …

Thinner than Kleenex®, as Powerful as the Sun

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David L. Chandler of the Massachusetts Institute of Technology (MIT) News Office reports that an MIT research team headed by Jeffrey Grossman has found a way to make sheets that push “towards the ultimate power conversion from a material” for solar power.  His team has managed to fabricate molecule-thick photovoltaic sheets which could pack hundreds of times more power per weight than conventional solar cells. Senior author of a new paper on the team’s study in Nano Letters, Grossman found that despite the interest in two-dimensional materials such as graphene – only an atom thick – few have studied their potential for solar applications.  Grossman says, “They’re not only OK, but it’s amazing how well they do.” Stacking sheets of …

GraphExeter Aims for Power with Transparency

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It doesn’t sound much like dispassionate, objective scholarly reporting, but the University of Exeter in England headlines its report on a University-created breakthrough material, “Revolutionary new device joins world of smart electronics.” Layering graphene and the GraphExeter, a material obviously headed for product marketing, gives a “new flexible, transparent, photosensitive device” that can lead to solar-powered clothing able to charge the wearer’s cell phone, “intelligent” windows that can “harvest light and display images,” and just maybe (in this writer’s dreams) help power electric cars and airplanes. GraphExeter, Exeter claims, is the best known room temperature transparent conductor and with graphene – the thinnest conductive material – the pair make for great potential.   Researchers  developed  GraphExeter by sandwiching molecules of …

Peel-and-Stick Solar Cells Make Debut

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The U. S. Department of Energy’s National Renewable Energy Laboratory (NREL) and Stanford University have teamed up to create what may be the thinnest of thin solar cells – a peel-and-stick decal. One micron thick, the decal-like  peel-and-stick, or water-assisted transfer printing (WTP), technologies were developed by Stanford researchers and have been used for nanowire based electronics.  Meeting at a conference where both made presentations, Stanford’s Xiaolin Zheng talked about her peel-and-stick technology, and NREL principal scientist Qi Wang spoke on his team’s research in thin-film amorphous solar cells. Zheng realized that the NREL had the type of solar cells needed for her peel-and-stick project, according to the NREL announcement. The NREL press release explains, “The university and NREL showed …

Alchemy with Thin Film Structures

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The blog has looked at several recent attempts to pull electricity from solar cells that have the ability to capture a broad range of light wavelengths.  These are based on everything from layers of graphene and zinc nano-wires, to an exotic subwavelength  plasmonic cavity, to straining solar cells to form wide bandgap funnels which capture light’s energy. Joining these efforts along with those of researchers in America and Germany, colleagues at the Vienna University of Technology are testing single atomic layers of oxide heterostructures, a new class of materials, to “create a new kind of extremely efficient ultra-thin solar cells.” Professor Karsten Held from the Institute for Solid State Physics at the University, explains, “Single atomic layers of different oxides …

Princeton Solar Cell is “Black Hole for Light”

Dean Sigler Electric Powerplants, Sustainable Aviation 2 Comments

A great deal of the light that falls on solar cell panels does little to generate electricity, with a high percentage bouncing off pointlessly.  Princeton researchers have confronted this issue with a layered assembly, otherwise known as a subwavelength  plasmonic cavity. Developed by Princeton University researcher Stephen Chou and a team of scientists, the cavity dampens reflections and traps light.  According to Princeton’s announcement, “The new technique allowed Chou’s team to create a solar cell that only reflects about 4 percent of light and absorbs as much as 96 percent. It demonstrates 52 percent higher efficiency in converting [direct] light to electrical energy than a conventional solar cell.” Overall, the team was able to increase solar cell efficiency a total …

Power Spraying Takes on a Whole New Meaning

Dean Sigler Electric Powerplants, Sustainable Aviation 4 Comments

Several news sources, apparently using the same press release from Mitsubishi Chemical Corp., have announced a spray-on solar cell, which can be applied in the same fashion as paint – to “buildings, vehicles and even clothing.”  This “means that the places where energy from the sun can be harvested are almost limitless.” Less than one millimeter thick and capable of 10.1-percent efficiency, the new material is said to have a weight one-tenth of traditional silicon cells.  Mitsubishi says these are prototype materials, and that they hope to achieve 15-percent efficiency by 2015, with 20 percent as a more distant possibility. Mitsubishi is a bit soft on details, but says, “The new solar cells utilize carbon compounds which, when dried and solidified, …

Not Your Father’s 172

Dean Sigler Electric Powerplants, Sustainable Aviation 1 Comment

George Bye, CEO of Bye Energy and head of the Green Flight Project, hopes to test fly the electric Cessna 172 in the spring of 2011.  Recent illustrations show the “full-dress” electric craft with Ascent solar cells, a high-tech propeller, streamlined cowling, and vortex collectors at the wing tips’ trailing edges.  Each element is intended to extend the range and efficiency of the airplane, a strong selling point, particularly in electrically-powered machines. Ascent Solar’s thin-film cells are thinner than a human hair, and thus will not impede the airflow over the wing’s surface. As the cells’ efficiency grows with development, they will provide greater flexibility of operation.  Their resistance to failure, demonstrated in the video, will enhance the reliability of …

The Light at the End of the Funnel

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In some exciting news that could make several quantum leaps in solar cell performance, Massachusetts Institute of Technology researchers have announced a hundred-fold increase in light gathering capabilities for solar cells. If a cell were able to exploit this increase, an aircraft such as the Solar Impulse could fly on 120 solar cells instead of the 12,000 now spread across its over 200-foot wingspan. We’ve reported on carpet-like light-capturing formats for increasing solar cell output, but the MIT approach funnels light down a multi-carbon nanotube filament, boosting the output of the “tiny” solar cell at the bottom. MIT’s press release explains the outcome. “’Instead of having your whole roof be a photovoltaic cell, you could have little spots that were …

Solar Impulse Overnighter: 26 Hours Nine Minutes

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Andre’ Borschberg, CEO and co-founder of the Solar Impulse project, landed this morning at 9:00 a.m. (local tme) in Payerne, Switzerland, having completed the first-ever night flight on battery energy stored during the previous day through the craft’s solar cells.  Taking off at 6:51 a.m. July 7, Borschberg flew the 64-meter span, four-motor airplane in large patterns around the area, gaining altitude to a height of 8,564 meters (27,404 feet) above sea level and charging the batteries – all while running the motors at climb power. As night fell, he glided to preserve the stored power, ran the motors as needed to maintain altitude, and landed with a small reserve.  This successful demonstration of being able to run the motors on …