A Material That Could Make Solar Power “Dirt Cheap”

A new type of solar cell, made from a material that is dramatically cheaper to obtain and use than silicon, could generate as much power as today’s commodity solar cells.

Although the potential of the material is just starting to be understood, it has caught the attention of the world’s leading solar researchers, and several companies are already working to commercialize it.

Researchers developing the technology say that it could lead to solar panels that cost just 10 to 20 cents per watt. Solar panels now typically cost about 75 cents a watt, and the U.S. Department of Energy says 50 cents per watt will allow solar power to compete with fossil fuel.

In the past, solar researchers have been divided into two camps in their pursuit of cheaper solar power. Some have sought solar cells that can be made very cheaply but that have the downside of being relatively inefficient. Lately, more researchers have focused on developing very high efficiency cells, even if they require more expensive manufacturing techniques.

Written by Kevin Bullis. To read the full article, click here.

Plastic Solar Cells’ New Design Promises Bright Future

Energy consumption is growing rapidly in the 21st century, with rising energy costs and sustainability issues greatly impacting the quality of human life. Harvesting energy directly from sunlight to generate electricity using photovoltaic technologies is considered to be one of the most promising opportunities to produce electricity in an environmentally benign fashion.

Among the various photovoltaic technologies, polymer (plastic) solar cells offer unique attractions and opportunities. These solar cells contain Earth-abundant and environmentally benign materials, can be made flexible and lightweight, and can be fabricated using roll-to-roll technologies similar to how newspapers are printed. But the challenge has been improving the cells’ power-conversion efficiency.

Now a research team of faculty members and students led by Professor Tobin J. Marks of Northwestern University reports the design and synthesis of new polymer semiconductors and reports the realization of polymer solar cells with fill factors of 80 percent — a first. This number is close to that of silicon solar cells.

Written by Science Daily. To read the full article, click here.

Transparent Solar Film Gets Big Efficiency Boost

A novel, transparent, two-layer solar film — possessing an impressive efficiency conversion of 7.3% — has been created by researchers at the University of California–Los Angeles. This is about double the transparent solar cell efficiency the researchers had previously achieved. The solar film can be placed on windows, buildings, sunroofs, electronics displays, etc; harvesting energy while still at the same time allowing light to pass through and visibility/transparency to be maintained.

The new solar film is essentially an improved form of the “breakthrough photovoltaic cell design” that the same researchers unveiled last year – an improved form with nearly double the efficiency, that is. It consists of two thin polymer solar cells that work together to maximize sunlight collection and conversion to electricity — the two cells absorb more light than single-layer solar devices do because together they absorb light from a wider part of the solar spectrum. There’s also a thin layer of ‘novel materials’ present between the two cells that works to reduce energy loss.

Written by Nathan. To read the full article, click here.

Best of Both Worlds: Solar Hydrogen Production Breakthrough

Using a simple solar cell and a photo anode made of a metal oxide, HZB and TU Delft scientists have successfully stored nearly five percent of solar energy chemically in the form of hydrogen. This is a major feat as the design of the solar cell is much simpler than that of the high-efficiency triple-junction cells based on amorphous silicon or expensive III-V semiconductors that are traditionally used for this purpose. The photo anode, which is made from the metal oxide bismuth vanadate (BiVO4) to which a small amount of tungsten atoms was added, was sprayed onto a piece of conducting glass and coated with an inexpensive cobalt phosphate catalyst.

“Basically, we combined the best of both worlds,” explains Prof. Dr. Roel van de Krol, head of the HZB Institute for Solar Fuels: “We start with a chemically stable, low cost metal oxide, add a really good but simple silicon-based thin film solar cell, and — voilà — we’ve just created a cost-effective, highly stable, and highly efficient solar fuel device.”

Thus the experts were able to develop a rather elegant and simple system for using sunlight to split water into hydrogen and oxygen. This process, called artificial photosynthesis, allows solar energy to be stored in the form of hydrogen. The hydrogen can then be used as a fuel either directly or in the form of methane, or it can generate electricity in a fuel cell. One rough estimate shows the potential inherent in this technology: At a solar performance in Germany of roughly 600 Watts per square meter, 100 square meters of this type of system is theoretically capable of storing 3 kilowatt hours of energy in the form of hydrogen in just one single hour of sunshine. This energy could then be available at night or on cloudy days.

Written by Science Daily. To read the full article, click here.

Stanford Researchers Develop Record-Breaking Thinner Solar Cells That Absorb More Light

Solar power research is a big deal. Scientists have been searching for a way to improve photovoltaic efficacy for years by developing new technologies – from giant solar concentrator arrays to satellites that beam power back to Earth. Now, Stanford University researchers have developed what they call the thinnest, most efficient photovoltaic wafers ever. Instead of increasing the size of the solar arrays, the researchers created solar wafers with a nano-sized structure that is 1,000 times thinner than any other commercially available thin-film solar cell absorbers.

According to the researchers, the thin film solar wafers are only 1.6 nanometers thin, which cuts down on materials required to produce the cells while making them lighter. At the same time, all of this was done without comprising the solar cells’ ability to absorb visible light. These smaller photovoltaic cells can actually absorb parts of the visible light spectrum with incredible efficiency.

“The coated wafers absorbed 99 percent of the reddish-orange light,” Carl Hagglund, postdoctoral scholar at Department of Chemical Engineering and lead author on the study, said in a statement. “We also achieved 93 percent [light] absorption in the gold nanodots themselves.”

Written by Kevin Lee. To read the full article, click here.

Build your own solar panels? Proceed with caution

A number of people have asked me about building their own solar panels from individual solar cells and asking for my opinion on a number of web sites that make claims that you can build enough solar panels to power your home for around $200.

I have a huge amount of respect for people with the aptitude and the ability to build their own equipment. These people often derive a great deal of personal satisfaction from being able to say, “I built that myself”. Largely, these people are to be encouraged. If you want to build your own solar panels, however, I would advise caution.

There have been many claims made from certain web sites that say it is possible to build your own solar panels and run your entire house from solar panels for an outlay of $200 or less, sell excess power back to the utility grid and even generate an income from solar.

Written by Michael Boxwell. To read the full article, click here.

Bringing Color to Solar Panels

Covering a roof or a façade with standard solar cells to generate electricity will change a building’s original appearance — and not always for the better. At present only dark solar panels are widely available on the market. “Not enough work has been done so far on combining photovoltaics and design elements to really do the term ‘customized photovoltaics’ justice,” says Kevin Füchsel, project manager at the Fraunhofer Institute for Applied Optics and Precision Engineering IOF in Jena.

But things are changing. The IOF physicist has been focusing for the last four years on nanostructured solar cells suitable for mass production as part of a junior research group funded by Germany’s Federal Ministry for Education and Research (BMBF). Together with a Fraunhofer team and scientists from the Friedrich-Schiller University in Jena, the group of optics specialists is looking for cost-effective techniques and manufacturing processes to increase both the efficiency of solar panels and the design flexibility they give architects and designers.

Written by Science Daily. To read the full article, click here.