The nanotechnology, what it does is it improves the efficiency of these solar cells by about 10,000 times

from a video from the National Defense Education Program:

10,000 times! He says it improves the efficiency 10,000 times!

"What we have here is a flexible solar cell. And it's a flexible solar cell that's only made possible through nanotechnology. Now you think of traditional solar cells—they're essentially giant pieces of silicon and they're made on glass. Well, this is very different from that. It's not made on glass. It's made on plastic, as you can see.

"Now, what we have here, it is nanostructured titanium dioxide with some organic(s) in there to absorb the light. The nanotechnology, what it does is it improves the efficiency of these solar cells by about 10,000 times. So you'll actually be able to go out and buy these flexible solar cells—maybe put them on your house—use them for other applications—but they'll be much cheaper than the solar panels you can get today."

—Joseph McDermott, Phd, nanomaterials scientist, Wright-Patterson Air Force Base

Well, plainly I don't know the details here, but the first thing I got on Google that contained "plastic based solar cells titanium dioxide organic" gave me this, which mentioned that efficiencies, as of 2006, were between .01 and .04%. A symposium in 2007 listed some not-quite-similar materials achieving 4-6% efficiency under some conditions. That's a several hundred percent improvement. Maybe the first non-nanostructured cells had unbelievably bad efficiencies, like .00001%. I don't know. It just seems like a 10,000 time increase is hard to imagine...

Large scale solar plants have a bright future

Gizmag.com:

September 14, 2007 Although the use of solar energy has is seen as viable for the operation of stand-alone devices such as phone-chargers and even a computer mouse, the question remains in some minds: is solar a viable alternative energy source on a mass scale? The proliferation of large scale solar power plants worldwide and plans to build several new ones seems to suggest that the renewable energy sector believes that solar does indeed have a bright future.

Germany and Japan have long led the field in solar thermal energy production however; it now seems that Spain is a hub for solar energy activity. This year alone Spain has witnessed the opening of a commercial solar power plant and a test facility with another plant due to open this month. The Seville Solar Station which went online in May comprises some 600 mirrors which focus sunlight onto water pipes at the top of a 40 storey tall concrete tower. The 11 megawatt plant was the first commercial solar station in Europe. This month Japan’s Kyocera Corporation announced its role as the sole supplier of photovoltaic (“PV”) modules for the massive new solar electric generating system in Salamanca, Spain, that will meet the needs of about 5,000 private households. The 13.8 megawatt facility, known as Planta Solar de Salamanca, will be one of the largest PV systems in the world and will commence operation on 18 September.

Although perhaps not the sunniest place on Earth, Germany is pioneering the field of solar energy production. The country is home to the Gut Erlasee Solar Park, a 12 megawatt facility located near the Bavarian town of Arnstein. The park powers the homes of 1,000 local residential customers each year. Peter Aschenbrenner, vice president of sales and marketing for SunPower Corp who make the panels that power the plant, says that their vision is “to make solar power a mainstream energy source.” Also located in Germany is the largest thin-film solar power plant in the world, the Rote Jahne. It is a 6 megawatt plant with the ability to produce 5.7 million kilowatt-hours of solar electricity each year which can power around 1,900 homes. The plant’s builder, Israeli company Juwi Solar, has commenced building a much larger 40-megawatt solar park due to be finished by the end of 2009.

The United States is now joining the race to increase solar capacity. In June 2007 the first concentrating solar power plant in Nevada went on line. The 64 megawatt facility is the first modern utility-scale solar electric power plant in the US and covers a whopping 250 acres of desert in the El Dorado Valley. It is the largest solar electric power plant to be built globally in the past 14 years and the third largest solar power plant in the world. Ironically, the money for the plant was not from that of American investors, but Spanish renewable energy company, Acciona Energia which invested US$262 million in the plant. Nevada could well be the site for more solar thermal plants with a deal signed in 2006 to build a 100 megawatt power plant for Solar Renewable Energy-1 LLC, a company based in the area. Another plant is planned for California with a 500 megawatt capability due for completion on 2012.

The manufacture and maintenance of solar panels has traditionally been hugely expensive which could account for the slowness of energy producers to switch to solar from current, unrenewable energy sources. Many organizations are now trying to address this issue to make solar more affordable. In July this year a new test facility to cut the cost of large-scale solar thermal energy production was opened in Almería in southern Spain. The test plant utilizes Fresnel reflectors which are a low-cost alternative to the use of expensive parabolic mirrors as a means of concentrating the suns rays. The plant will undertake practical tests which it is hoped will lead to the construction of more affordable commercial solar thermal power plants. Solar panel manufacturer, Applied Materials, has introduced an integrated production line for manufacturing thin-film solar modules designed to achieve low production cost per watt and drive down the cost of solar electricity installations by around 20%.

With the number of commercial solar plants growing at a rapid rate and the huge investment into research and development to make solar energy more affordable it seems that yes, solar has the potential to become a viable alternative energy source on a mass scale. Solar is a particularly attractive option for countries with vast expanses of uninhabitable desert. With the sun being one of our few freely available, infinite resources, it will be vital to our future survival to harness the power of the sun and alleviate our current reliance on finite resources which are fast running out.

Paint-on solar cells a step closer to reality

more from Physorg.com:

Researchers at New Jersey Institute of Technology have developed an inexpensive solar cell that can be painted or printed on flexible plastic sheets.

NJIT researchers develop inexpensive,
easy process to produce solar panels.
Credit: New Jersey Institute of Technology

“The process is simple,” said lead researcher and author Somenath Mitra, PhD, professor and acting chair of NJIT’s Department of Chemistry and Environmental Sciences. “Someday homeowners will even be able to print sheets of these solar cells with inexpensive home-based inkjet printers. Consumers can then slap the finished product on a wall, roof or billboard to create their own power stations.”

“Fullerene single wall carbon nanotube complex for polymer bulk heterojunction photovoltaic cells,” featured as the June 21, 2007 cover story of the Journal of Materials Chemistry published by the Royal Society of Chemistry, details the process.

The science goes something like this. When sunlight falls on an organic solar cell, the energy generates positive and negative charges. If the charges can be separated and sent to different electrodes, then a current flows. If not, the energy is wasted. Link cells electronically and the cells form what is called a panel, like the ones currently seen on most rooftops. The size of both the cell and panels vary. Cells can range from 1 millimeter to several feet; panels have no size limits.

The solar cell developed at NJIT uses a carbon nanotubes complex, which by the way, is a molecular configuration of carbon in a cylindrical shape. The name is derived from the tube’s miniscule size. Scientists estimate nanotubes to be 50,000 times smaller than a human hair. Nevertheless, just one nanotube can conduct current better than any conventional electrical wire. “Actually, nanotubes are significantly better conductors than copper,” Mitra added.

Mitra and his research team took the carbon nanotubes and combined them with tiny carbon Buckyballs (known as fullerenes) to form snake-like structures. Buckyballs trap electrons, although they can’t make electrons flow. Add sunlight to excite the polymers, and the buckyballs will grab the electrons. Nanotubes, behaving like copper wires, will then be able to make the electrons or current flow.

“Using this unique combination in an organic solar cell recipe can enhance the efficiency of future painted-on solar cells,” said Mitra. “Someday, I hope to see this process become an inexpensive energy alternative for households around the world.”