David Kirkpatrick

April 21, 2010

Lowering the cost of thin-film solar

Yesterday I blogged about an efficiency breakthrough in thin-film solar cells, and now here’s more news on a cost breakthrough. I’m going to quote myself from the earlier post, “I keep hammering on the same point, but cost and efficiency in combination are the key to making solar a commercially viable option.” Be sure to hit the solar link in the “Interesting Blog Topics” box over on the sidebar for all my solar power blogging.

From the second link:

Advance made in thin-film solar cell technology

CORVALLIS, Ore. – Researchers have made an important breakthrough in the use of continuous flow microreactors to produce thin film absorbers for solar cells – an innovative technology that could significantly reduce the cost of solar energy devices and reduce material waste.

The advance was just reported in Current Applied Physics, a professional journal, by engineers from Oregon State University and Yeungnam University in Korea.

This is one of the first demonstrations that this type of technology, which is safer, faster and more economical than previous chemical solution approaches, could be used to continuously and rapidly deposit thin film absorbers for solar cells from such compounds as copper indium diselenide.

Previous approaches to use this compound – which is one of the leading photovoltaic alternatives to silicon-based solar energy devices – have depended on methods such as sputtering, evaporation, and electrodeposition. Those processes can be time-consuming, or require expensive vacuum systems or exotic chemicals that raise production costs.

Chemical bath deposition is a low-cost deposition technique that was developed more than a century ago. It is normally performed as a batch process, but changes in the growth solution over time make it difficult to control thickness. The depletion of reactants also limits the achievable thickness.

The technology invented at Oregon State University to deposit “nanostructure films” on various surfaces in a continuous flow microreactor, however, addresses some of these issues and makes the use of this process more commercially practical. A patent has been applied for on this approach, officials said.

“We’ve now demonstrated that this system can produce thin-film solar absorbers on a glass substrate in a short time, and that’s quite significant,” said Chih-hung Chang, an associate professor in the OSU School of Chemical, Biological and Environmental Engineering. “That’s the first time this has been done with this new technique.”

Further work is still needed on process control, testing of the finished solar cell, improving its efficiency to rival that of vacuum-based technology, and scaling up the process to a commercial application, Chang said.

Of some interest, researchers said, is that thin-film solar cells produced by applications such as this could ultimately be used in the creation of solar energy roofing systems. Conceptually, instead of adding solar panels on top of the roof of a residential or industrial building, the solar panel itself would become the roof, eliminating such traditional approaches as plywood and shingles.

“If we could produce roofing products that cost-effectively produced solar energy at the same time, that would be a game changer,” Chang said. “Thin film solar cells are one way that might work. All solar applications are ultimately a function of efficiency, cost and environmental safety, and these products might offer all of that.”

The research has been supported by the Process and Reaction Engineering Program of the National Science Foundation.

Related technology was also developed recently at OSU using nanostructure films as coatings for eyeglasses, which may cost less and work better than existing approaches. In that case, they would help capture more light, reduce glare and also reduce exposure to ultraviolet light. Scientists believe applications in cameras and other types of lenses are also possible.

More work such as this is expected to emerge from the new Oregon Process Innovation Center for Sustainable Solar Cell Manufacturing, a $2.7 million initiative based at OSU that will include the efforts of about 20 faculty from OSU, the University of Oregon, Portland State University and the Pacific Northwest National Laboratory.

Organizers of that initiative say they are aiming for “a revolution in solar cell processing and manufacturing” that might drop costs by as much as 50 percent while being more environmentally sensitive. In the process, they hope to create new jobs and industries in the Pacific Northwest.

###

Advertisements

March 24, 2010

GE getting into thin-film solar field

This can only mean advances in production and manufacturing coupled with a likely cost reduction. A win for the field since GE is going to bring to bear its corporate might on process improvements.

From the link:

GE has confirmed long-standing speculation that it plans to make thin-film solar panels that use a cadmium- and tellurium-based semiconductor to capture light and convert it into electricity. The GE move could put pressure on the only major cadmium-telluride solar-panel maker, Tempe, AZ-based First Solar, which could drive down prices for solar panels.

Last year, GE seemed to be getting out of the solar industry as it sold off crystalline-silicon solar-panel factories it had acquired in 2004. The company found that the market for such solar panels–which account for most of the solar panels sold worldwide–was too competitive for a relative newcomer, says Danielle Merfeld, GE’s solar technology platform leader.

February 19, 2010

Broadband Solar offers latest breakthrough

Seems like I’ve been doing a whole lot of solar blogging lately, and here’s the latest breakthrough courtesy of Broadband Solar. This sounds more like an incremental improvement that will possibly lead to commercially viable thin-film solar cells rather than a game-changer ready for market. Even if this announcement doesn’t make it immediately easier or cheaper to put a bank of thin-film cells on the roof of your house, it is one more step toward that goal

From the second link:

Inexpensive thin-film solar cells aren’t as efficient as conventional solar cells, but a new coating that incorporates nanoscale metallic particles could help close the gap. Broadband Solar, a startup spun out of Stanford University late last year, is developing coatings that increase the amount of light these solar cells absorb.

Based on computer models and initial experiments, an amorphous silicon cell could jump from converting about 8 percent of the energy in light into electricity to converting around 12 percent. That would make such cells competitive with the leading thin-film solar cells produced today, such as those made by First Solar, headquartered in Tempe, AZ, says Cyrus Wadia, codirector of the Cleantech to Market Program in the Haas School of Business at the University of California, Berkeley. Amorphous silicon has the advantage of being much more abundant than the materials used by First Solar. The coatings could also be applied to other types of thin-film solar cells, including First Solar’s, to increase their efficiency.

Solar antenna: The square at the center is an array of test solar cells being used to evaluate a coating that contains metallic nanoantennas tuned to the solar spectrum.
Credit: Brongersma lab, Stanford

December 8, 2008

Thin-film solar

It’s been a while since I’ve blogged about a solar breakthrough. Not sure if the spate earlier this year came on the heels of a lot of concurrent research, or if everyone was just trying to announce early-versions of coming tech because oil was so high priced.

If it was the latter expect little alternative fuel news since the market pressure won’t be there until oil heads back toward three figures a barrel. That might be a while.

At any rate efficient thin-film solar sounds like a promising tech.

From the link:

Researchers at MIT have unveiled a new type of silicon solar cell that could be much more efficient and cost less than currently used solar cells. Materials science and engineering professor Lionel Kimerling and his colleagues presented results of the first device prototype at a recent meeting of the Materials Research Society in Boston.

The design combines a highly effective reflector on the back of a solar cell with an antireflective coating on the front. This helps trap red and near-infrared light, which can be used to make electricity, in the silicon. The research team is licensing similar technology to StarSolar, a startup in Cambridge, MA.

The researchers applied their light-trapping scheme on thin silicon cells that are about five micrometers thick. Their prototype solar cell is 15 percent more efficient at converting light into electricity than commercial thin-film solar cells. Project leader Peter Bermel, who is StarSolar’s chief technology officer, says that sophisticated computer simulations suggest that much greater gains in efficiency are possible.

Lirong Zeng

Light trapper: A transmission electron microscopy (TEM) image shows the back surface of a five-micrometer-thick silicon solar cell. The alternating layers of silicon and silicon dioxide form an excellent light reflector. The crests and troughs send the reflected light into the silicon at a low angle that keeps it trapped inside the silicon for a long time, increasing the efficiency of the cell. Credit: Lirong Zeng

July 31, 2008

Thin-film solar continues growth

Filed under: Science, Technology — Tags: , , , — David Kirkpatrick @ 1:31 pm

From KurzweilAI.net, thin-film solar cells are a very promising technology in making solar more affordable and feasible. According to the linked article this tech looks to continue its strong growth.

Thin films: ready for their close-up?
Nature News, July 30 2008

New thin-film solar cells may enable solar-cell technology to maintain its 50% annual growth during the past five years.

Candidate materials to replace today’s amorphous silicon include cadmium telluride, CIGS (copper indium gallium diselenide), and dyes painted onto the surface of nanometer-size particles of titanium dioxide.

In sunny climates, the technology is expected to lead to “grid parity” — electricity generated by photovoltaics as cheaply as it is sold by utilities — within four years or so.

 
Read Original Article>>