Photosynthesis Directly Makes Fuel

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

That’s what photosynthesis does in leaves – creates fuel in the form of plant sugars that flow into the plant to which the leaf is attached.  One of the main quibbles about trying to convert solar energy to usable fuel is the usual multi-step process involved.  Researchers at the University of Illinois at Chicago have made a major advance in creating a solar cell that captures carbon dioxide (CO2) and uses sunlight to make a synthetic gas that can be burned as fuel. Scientists rarely use hyperbolic terms such as “extraordinary” in their findings.  According to Amin Salehi-Khojin, assistant professor of mechanical and industrial engineering at UIC, “What we needed was a new family of chemicals with extraordinary properties.”  They …

Daniel Nocera Returns to the Artificial Leaf

Dean Sigler Biofuels, Solar Power, Sustainable Aviation 0 Comments

Many scientists are turning to mimicking nature to probe its secrets, but Daniel Nocera, the Patterson Rockwood Professor of Energy at Harvard University, has gone far beyond his natural model.  Reported in 2012, Nocera came up with the idea of an “artificial leaf,” a silicon sheet with a layer of cobalt-based catalyst that releases oxygen on one side and a layer a nickel-molybdenum-zinc alloy on the other side that releases hydrogen.  Several researchers have followed this initial breakthrough, trying different materials and combinations of ingredients. For a while, it looked as though Nocera turned his attention to battery development, but recent news shows he’s back investigating artificial leaves – with great improvements over his initial efforts – and those of …

Cambridge’s “Ultimate” Battery? Wait 10 Years and See

Dean Sigler Batteries, Electric Aircraft Materials, Electric Powerplants 0 Comments

Cambridge University researchers claim to have successfully demonstrated how several of the problems impeding the practical development of the so-called “ultimate” battery, in this case a lithium-oxygen unit, could be overcome.  They make some pretty impressive claims, saying they’ve developed a working laboratory demonstrator with “very high” energy density – comparable to that of gasoline and with greater than 90-percent efficiency, and the ability to be recharged more than 2,000 times, or 5-1/2 years with a complete cycle and recharge every day. A lithium-oxygen or lithium-air battery of this type would allow an uninterrupted drive between London and Edinburgh on a single charge, about 415 miles, over 100 miles greater than the top mileages promised by Tesla and GM at …

More Powerful, Longer Lasting Perovskites

Dean Sigler Electric Aircraft Materials, Solar Power, Sustainable Aviation 0 Comments

Perovskites, calcium titanium oxide minerals composed of calcium titanate, with the chemical formula CaTiO, are found in relative abundance throughout the world and have  characteristics that make them a plausible candidate for use in solar cells. Initially showing good efficiency at small scales, perovskite solar cells were potentially less expensive to produce than conventional silicon-based units, and could be more efficient, especially as single-layer silicon cells reach their theoretical limit of 30-percent efficiency.  Perovskite cells could be configured to respond to different wavelengths of light, stacked on one another, and still be thinner than conventional solar cells. Part of the attraction of perovskites cells has been their rapid increase in efficiency, nearly equaling the best silicon cells in about six years, as opposed to the 35 …

Combining the Best Features of Balsa Wood, Ceramics and NERF®

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

California Institute of Technology (CalTech) floats this imaginary trial balloon to elicit interest in a new material developed by materials scientist Julia Greer and her colleagues.  “Imagine a balloon that could float without using any lighter-than-air gas. Instead, it could simply have all of its air sucked out while maintaining its filled shape. Such a vacuum balloon, which could help ease the world’s current shortage of helium, can only be made if a new material existed that was strong enough to sustain the pressure generated by forcing out all that air while still being lightweight and flexible.” Not only are the scientists achieving the strong, lightweight part of the equation, they are “on the path” to making their new material …

Cheap Hydrogen, Anyone?

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Researchers in Glasgow and at Stanford University have devised ways to decouple oxygen and hydrogen from water without resort to expensive extraction or storage techniques.  Both breakthroughs involve low-cost materials, low-energy requirements, and the production of clean hydrogen through what should be renewable energy resources. The latter overcomes one major objection to hydrogen production.  As Professor Lee Cronin of the University of Glasgow’s School of Chemistry explains, “Around 95% of the world’s hydrogen supply is currently obtained from fossil fuels, a finite resource which we know harms the environment and speeds climate change. Some of this hydrogen is used to make ammonia fertilizer and as such, fossil hydrogen helps feed more than half of the world’s population. “The potential for …

Taking That Fork in the Solar Road

Dean Sigler Diesel Powerplants, Electric Powerplants, Sustainable Aviation 0 Comments

Kyoung-Shin Choi, a chemistry professor at the University of Wisconsin-Madison, and postdoctoral researcher Tae Woo Kim combined forces to come up with a two-pronged approach for producing stored energy from mere sunlight. Many researchers take the familiar path of using expensive materials to extract the greatest percentage of energy from solar cells, but others use low-cost, less efficient organic materials spread across a greater area to get the same results.  Choi and Kim, though, decided that selecting two different low-cost materials could give greater results – something a more single-path approach would miss. As their U of W report states, “Generating electricity is not the only way to turn sunlight into energy we can use on demand. The sun can also …

Making Graphene and Carbon Fibers Even Lighter and Stronger

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

While scientists at Columbia University have used chemical vapor deposition (CVD) to create large sheets of stronger-than-average graphene, a research team at Massachusetts Institute of Technology (MIT) has found ways to weave stronger carbon nanotubes. James Hone and Jeffrey Kysar, professors of mechanical engineering at Columbia University, learned that the enormous strength of graphene is usually achieved in only small patches.  The “grain boundaries” for larger sheets were often far weaker than the theoretical strengths of which the material is capable. That strength is phenomenal.  Hone explains, “It would take an elephant, balanced on a pencil, to break through a sheet of graphene the thickness of Saran Wrap.” Results of their study were published in the journal Science. The paper’s …