[amor de cosmos]

CTRL+P: Printing Australia’s largest solar cells
16 May 2013

Scientists have produced the largest flexible, plastic solar cells in Australia – ten times the size of what they were previously able to – thanks to a new solar cell printer that has been installed at CSIRO.

he printer has allowed researchers from the Victorian Organic Solar Cell Consortium (VICOSC) – a collaboration between CSIRO, The University of Melbourne, Monash University and industry partners – to print organic photovoltaic cells the size of an A3 sheet of paper.

According to CSIRO materials scientist Dr Scott Watkins, printing cells on such a large scale opens up a huge range of possibilities for pilot applications.
"There are so many things we can do with cells this size," he says. "We can set them into advertising signage, powering lights and other interactive elements. We can even embed them into laptop cases to provide backup power for the machine inside."

The new printer, worth A$200,000, is a big step up for the VICOSC team. In just three years they have gone from making cells the size of a fingernail to cells 10cm square. Now with the new printer they have jumped to cells that are 30cm wide.

VICOSC project coordinator and University of Melbourne researcher Dr David Jones says that one of the great advantages of the group's approach is that they're using existing printing techniques, making it a very accessible technology.

"We're using the same techniques that you would use if you were screen printing an image on to a T-Shirt," he says.

Using semiconducting inks, the researchers print the cells straight onto paper-thin flexible plastic or steel. With the ability to print at speeds of up to ten metres per minute, this means they can produce one cell every two seconds.

As the researchers continue to scale up their equipment, the possibilities will become even greater.

http://newsroom.melbourne.edu/news/c...st-solar-cells
http://inhabitat.com/australias-larg...y-two-seconds/

SolarCity Raises $500M From Goldman Sachs to Finance Solar Roofs
Looking to include customers with lower credit scores
Eric Wesoff: May 16, 2013

SolarCity (Nasdaq: SCTY), a provider of distributed energy, just announced a $500 million lease financing agreement with Goldman Sachs (NYSE: GS). That translates to more than 100 megawatts of solar power.

The combined lease is the largest of its kind for U.S. residential rooftops.

SolarCity allows consumers to get electricity from grid-tied solar rooftops at lower rates than the utility through leasing or power purchase agreements (PPAs). SolarCity specifically mentions the goal of opening up solar to consumers with lower credit scores in this release.

Jimmy Chuang, SolarCity’s VP of structured finance, said, “We expect to be able to expand our offering to a broader customer base by lowering the credit requirements even further in future financings," according to a statement.

http://www.greentechmedia.com/articl...ce-Solar-Roofs

Artificial Forest for Solar Water-Splitting
Berkeley Lab Researchers Report First Fully Integrated Artificial Photosynthesis Nanosystem
May 16, 2013
Lynn Yarris

In the wake of the sobering news that atmospheric carbon dioxide is now at its highest level in at least three million years, an important advance in the race to develop carbon-neutral renewable energy sources has been achieved. Scientists with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) have reported the first fully integrated nanosystem for artificial photosynthesis. While “artificial leaf” is the popular term for such a system, the key to this success was an “artificial forest.”

“Similar to the chloroplasts in green plants that carry out photosynthesis, our artificial photosynthetic system is composed of two semiconductor light absorbers, an interfacial layer for charge transport, and spatially separated co-catalysts,” says Peidong Yang, a chemist with Berkeley Lab’s Materials Sciences Division, who led this research. “To facilitate solar water- splitting in our system, we synthesized tree-like nanowire heterostructures, consisting of silicon trunks and titanium oxide branches. Visually, arrays of these nanostructures very much resemble an artificial forest.”

Yang, who also holds appointments with the University of California Berkeley’s Chemistry Department and Department of Materials Science and Engineering, is the corresponding author of a paper describing this research in the journal NANO Letters. The paper is titled “A Fully Integrated Nanosystem of Semiconductor Nanowires for Direct Solar Water Splitting.” Co-authors are Chong Liu, Jinyao Tang, Hao Ming Chen and Bin Liu.

Solar technologies are the ideal solutions for carbon-neutral renewable energy – there’s enough energy in one hour’s worth of global sunlight to meet all human needs for a year. Artificial photosynthesis, in which solar energy is directly converted into chemical fuels, is regarded as one of the most promising of solar technologies. A major challenge for artificial photosynthesis is to produce hydrogen cheaply enough to compete with fossil fuels. Meeting this challenge requires an integrated system that can efficiently absorb sunlight and produce charge-carriers to drive separate water reduction and oxidation half-reactions.

http://newscenter.lbl.gov/news-relea...ter-splitting/