Supply Threats Persist For Thin-Film Solar Materials Due To Competition
One year ago, a report from the U.S. Department of Energy (DOE) on the global supply of essential PV module materials predicted possible disruptions for thin-film manufacturing.
The availability of indium, gallium and tellurium was examined in the context of current and future production needs, and the DOE found cause for concern. Indium and tellurium were pegged as especially vulnerable to supply tightness and price volatility, according to both the report and several market analysts at the time.
(See “New Government Report Identifies Supply Risks For Thin-Film PV Materials” in the February 2011 issue of Solar Industry.)
Now, the DOE has released the latest edition of its Critical Materials Strategy. Have the worries over thin-film PV materials supply eased? According to the DOE, the general supply-demand picture for indium, gallium and tellurium has “improved slightly,” but the situation is not entirely reassuring. The three metals are still highlighted (alongside neodymium and dysprosium) as clean-energy materials that face a “significant risk of supply chain bottlenecks in the next two decades.”
The report attributes the slight improvement primarily to decreased demand for the three thin-film materials: Although PV deployment is expected to grow, the requirements of the materials per module are expected to shrink.
For copper indium gallium diselenide (CIGS) modules, manufacturers are shifting to compositions with higher proportions of gallium and lower concentrations of indium, the DOE says. The result is a “partial trade-off in the potential for supply risk between the two elements.” At the same time, CIGS’ market share assumption has been reduced under the DOE’s new calculations, lowering projected demand for both indium and gallium.
Cadmium telluride (CdTe) thin-film modules currently account for approximately 10% of the PV market, according to the report. Declining silicon prices may threaten this slice of the market, but high tellurium costs and the increasing need for CdTe manufacturers to compete for supply with non-PV companies requiring tellurium continue to cause supply headaches.
“The cost of tellurium is a critical issue for CdTe solar cell makers, and the industry is working to lower material use and increasing recovery of new scrap to reduce reliance on primary tellurium,” the DOE says in the report.
Although short-term supply of tellurium appears adequate, future capacity increases may be insufficient to supply both CdTe manufacturing and the multitude of other manufacturing sectors that use tellurium. Under one scenario modeled in the report, tellurium supply would need to increase 50% more than its projected 2015 total in order to meet expected demand.
Indium and gallium have also experienced increased popularity in non-PV manufacturing uses, such as semiconductor applications, flat-panel displays, and coatings for smartphones and tablet computers. The DOE forecasts that as a result, supplies may run short by 2015 unless production of these materials is increased - or non-PV demand lessens.
Of the two metals, gallium poses more cause for concern, as the DOE has adjusted its assumptions of future gallium use under CIGS manufacturers’ expected manufacturing modifications.
“These higher estimates [of gallium requirements] are driven largely by the assumption that gallium will increasingly be substituted for indium in CIGS composition,” the DOE explains. This change points to the benefits of reducing material intensity in other aspects of PV manufacturing, such as reducing cell thickness and improving processing efficiency.
Overall, indium, gallium and tellurium all receive moderate scores (2 or 3 on a scale of 1 to 4) from the DOE with regard to both their importance to clean energy and short- and medium-term supply risk.
In order to help mitigate possible supply disruptions that could threaten the manufacturing and deployment of PV, as well as other types of clean energy, the agency has developed a three-pronged approach.
“First, diversified global supply chains are essential,” the DOE stresses in the report. “To manage supply risk, multiple sources of materials are required. This means taking steps to facilitate extraction, processing and manufacturing here in the United States, as well as encouraging other nations to expedite alternative supplies.”
The second strategy relies on developing alternatives to materials whose supply may be constrained. For PV, one DOE research program focuses on advancements in thin-film formulations such as copper-zinc-tin and sulfide-selenide. Another initiative funds research and development into PV inks based on earth-abundant materials such as zinc, sulfur and copper.
“Several projects also seek to use iron pyrite - also known as fool’s gold - to develop prototype solar cells,” the DOE notes in the report. “Pyrite is non-toxic, inexpensive, and is the most abundant sulfide mineral in the Earth’s crust.”
Finally, improving recycling and reuse mechanisms can reduce demand for new materials, the DOE says, adding that these strategies also can help improve the sustainability of manufacturing processes.
Source: http://www.aer-online.com/e107_plugins/content/content.php?content.9408
Photo: Enbridge Inc.’s 5 MW Tilbury solar project in Ontario uses First Solar’s cadmium telluride thin-film modules. Photo credit: Enbridge
Supply Threats Persist For Thin-Film Solar Materials Due To Competition
One year ago, a report from the U.S. Department of Energy (DOE) on the global supply of essential PV module materials predicted possible disruptions for thin-film manufacturing.
The availability of indium, gallium and tellurium was examined in the context of current and future production needs, and the DOE found cause for concern. Indium and tellurium were pegged as especially vulnerable to supply tightness and price volatility, according to both the report and several market analysts at the time.
Now, the DOE has released the latest edition of its Critical Materials Strategy. Have the worries over thin-film PV materials supply eased? According to the DOE, the general supply-demand picture for indium, gallium and tellurium has “improved slightly,” but the situation is not entirely reassuring. The three metals are still highlighted (alongside neodymium and dysprosium) as clean-energy materials that face a “significant risk of supply chain bottlenecks in the next two decades.”
The report attributes the slight improvement primarily to decreased demand for the three thin-film materials: Although PV deployment is expected to grow, the requirements of the materials per module are expected to shrink.
For copper indium gallium diselenide (CIGS) modules, manufacturers are shifting to compositions with higher proportions of gallium and lower concentrations of indium, the DOE says. The result is a “partial trade-off in the potential for supply risk between the two elements.” At the same time, CIGS’ market share assumption has been reduced under the DOE’s new calculations, lowering projected demand for both indium and gallium.
Cadmium telluride (CdTe) thin-film modules currently account for approximately 10% of the PV market, according to the report. Declining silicon prices may threaten this slice of the market, but high tellurium costs and the increasing need for CdTe manufacturers to compete for supply with non-PV companies requiring tellurium continue to cause supply headaches.
“The cost of tellurium is a critical issue for CdTe solar cell makers, and the industry is working to lower material use and increasing recovery of new scrap to reduce reliance on primary tellurium,” the DOE says in the report.
Although short-term supply of tellurium appears adequate, future capacity increases may be insufficient to supply both CdTe manufacturing and the multitude of other manufacturing sectors that use tellurium. Under one scenario modeled in the report, tellurium supply would need to increase 50% more than its projected 2015 total in order to meet expected demand.
Indium and gallium have also experienced increased popularity in non-PV manufacturing uses, such as semiconductor applications, flat-panel displays, and coatings for smartphones and tablet computers. The DOE forecasts that as a result, supplies may run short by 2015 unless production of these materials is increased - or non-PV demand lessens.
Of the two metals, gallium poses more cause for concern, as the DOE has adjusted its assumptions of future gallium use under CIGS manufacturers’ expected manufacturing modifications.
“These higher estimates [of gallium requirements] are driven largely by the assumption that gallium will increasingly be substituted for indium in CIGS composition,” the DOE explains. This change points to the benefits of reducing material intensity in other aspects of PV manufacturing, such as reducing cell thickness and improving processing efficiency.
Overall, indium, gallium and tellurium all receive moderate scores (2 or 3 on a scale of 1 to 4) from the DOE with regard to both their importance to clean energy and short- and medium-term supply risk.
In order to help mitigate possible supply disruptions that could threaten the manufacturing and deployment of PV, as well as other types of clean energy, the agency has developed a three-pronged approach.
“First, diversified global supply chains are essential,” the DOE stresses in the report. “To manage supply risk, multiple sources of materials are required. This means taking steps to facilitate extraction, processing and manufacturing here in the United States, as well as encouraging other nations to expedite alternative supplies.”
The second strategy relies on developing alternatives to materials whose supply may be constrained. For PV, one DOE research program focuses on advancements in thin-film formulations such as copper-zinc-tin and sulfide-selenide. Another initiative funds research and development into PV inks based on earth-abundant materials such as zinc, sulfur and copper.
“Several projects also seek to use iron pyrite - also known as fool’s gold - to develop prototype solar cells,” the DOE notes in the report. “Pyrite is non-toxic, inexpensive, and is the most abundant sulfide mineral in the Earth’s crust.”
Finally, improving recycling and reuse mechanisms can reduce demand for new materials, the DOE says, adding that these strategies also can help improve the sustainability of manufacturing processes.
By: SI Staff
Source: http://www.aer-online.com/e107_plugins/content/content.php?content.9408
Photo: Enbridge Inc.’s 5 MW Tilbury solar project in Ontario uses First Solar’s cadmium telluride thin-film modules. Photo credit: Enbridge
Semiconductor material gallium nitride is non-toxic and is compatible with human cells
(Nanowerk News) Researchers from North Carolina State University and Purdue University have shown that the semiconductor material gallium nitride (GaN) is non-toxic and is compatible with human cells – opening the door to the material’s use in a variety of biomedical implant technologies.
GaN is currently used in a host of technologies, from LED lighting to optic sensors, but it is not in widespread use in biomedical implants. However, the new findings from NC State and Purdue mean that GaN holds promise for an array of implantable technologies – from electrodes used in neurostimulation therapies for Alzheimer’s to transistors used to monitor blood chemistry.
“The first finding is that GaN, unlike other semiconductor materials that have been considered for biomedical implants, is not toxic. That minimizes risk to both the environment and to patients,” says Dr. Albena Ivanisevic, who co-authored a paper describing the research (“Gallium Nitride is Biocompatible and Non-Toxic Before and After Functionalization with Peptides”). Ivanisevic is an associate professor of materials science and engineering at NC State and associate professor of the joint biomedical engineering program at NC State and the University of North Carolina at Chapel Hill.
Researchers used a mass spectrometry technique to see how much gallium is released from GaN when the material is exposed to various environments that mimic conditions in the human body. This is important because gallium oxides are toxic. But the researchers found that GaN is very stable in these environments – releasing such a tiny amount of gallium that it is non-toxic.
The researchers also wanted to determine GaN’s potential biocompatibility. To do this they bonded peptides – the building blocks that make up proteins – to the GaN material. Researchers then placed peptide-coated GaN and uncoated GaN into cell cultures to see how the material and the cells interacted.
Researchers found that the peptide-coated GaN bonded more effectively with the cells. Specifically, more cells bonded to the material and those cells spread over a larger area.
“This matters because we want materials that give us some control over cell behavior,” Ivanisevic says. “For example, being able to make cells adhere to a material or to avoid it.
“One problem facing many biomedical implants, such as sensors, is that they can become coated with biological material in the body. We’ve shown that we can coat GaN with peptides that attract and bond with cells. That suggests that we may also be able to coat GaN with peptides that would help prevent cell growth – and keep the implant ‘clean.’ Our next step will be to explore the use of such ‘anti-fouling’ peptides with GaN.”
Source: By Matt Shipman, North Carolina State University
Solar cell breakthrough could hit 40 percent efficiency
Researchers using novel materials to build photovoltaic cells say their efforts could nearly double the efficiency of silicon-based solar cells.
The cells being developed by teams from the University of Arkansas and Arkansas State University have the potential to achieve a light-to-energy conversion rate, or solar efficiency, of 40 percent or better, according to the researchers.
The photovoltaic cells are intended for use in satellites and space instruments. Currently, the silicon-based solar cells that NASA uses in its satellites and instruments have efficiencies of only up to 23 percent, according to NASA statistics.
And today it was announced that the research teams are getting more money-a total of $1 million in new funding-to further their work. Of that, about $735,000 will come from NASA, $237,000 from the University of Arkansas, and $86,000 from Arkansas State.
Omar Manasreh, professor of electrical engineering at the Optoelectronics Research Lab at the University of Arkansas, has been developing the technology so far with a $1.3 million grant from the U.S. Air Force Office of Scientific Research. He leads the research team along with Liangmin Zhang, assistant professor at Arkansas State.
“It [the grant] will create new opportunities for further development in the field of novel photovoltaic materials and devices,” Manasreh said in a statement.
Manasreh has been testing two separate methods for growing metallic nanoparticles using a novel combination of materials as the semiconductor. While CIGS (copper, indium, gallium and selenium) solar cells are not uncommon, Manasreh is using a variation of CIGS-based cells-CuInSe2 and CuInGaSe2-to generate molecules that bind to a central atom and that are known as volatile ligands. The nanocrystals can then be converted into thin-film solar cells, or incorporated into nanotubes, by combining the material with either titanium dioxide or zinc oxide. His second approach uses indium arsenide (InAs) a material commonly used in infrared detectors.
“The second approach uses molecular beam epitaxy, a method of depositing nanocrystals, to create quantum dots made of indium arsenide (InAs). Quantum dots are nano-sized particles of semiconductor material,” according to the University of Arkansas.
When exposed to ultraviolet light, the nanocrystals grown in liquid emit brighter light enhancing the response of the nanocrystals. The phenomenon shows the potential to increase the energy conversion efficiency of the materials (see photo).
This research team isn’t the first to experiment with growing nanoparticles using liquid. In 2007, Calif-based company Innovalight developed a “silicon ink” for creating crystalline silicon solar cells that works by inserting nanoparticles into a solvent, pouring the liquid on a substrate, and then removing the liquid to be left with a silicon crystalline structure. At the time, the solar cells made from the method had a 22 percent efficiency. Innovalight was acquired by Dupont earlier this year.
by Candace Lombardi
Source: news.cnet.com
Alternative Metals to Gold and Silver
The last decade has been a wonderful time for Gold Bugs and Silver Bugs. We have profited and protected our wealth against inflation. Gold has risen from around $250 per ounce in 2001 to a recent high of $1917.90 and silver has risen from around $5 per ounce in 2001 to a recent high of $49.81. These numbers are quite exciting for anyone involved in the precious metals markets. Being a Silver Bug myself, I have to admit the ride up has been rather erratic. Long ago I had to learn to ignore the daily Comex price of Silver. Gold and Silver will continue to be an important part of my future holdings, but going forward I am beginning diversification into other metals. Here is a brief overview of some of the rare industrial metals I like and why I believe they are a good choice for anyone who believes in holding physical metals as part of their asset strategy.
There are many who believe the world is in a recession and this may be true in the USA, EU, and other Western nations. There are a few of us who still believe that the speed of industry and commerce is accelerating. I have spent time in Africa, had an opportunity to live in Europe for a few years and I currently live in Panama. This experience has opened my eyes to what is happening outside of the USA. What I see is a great mass of people who were once walking now driving cars. These same people are talking on mobile phones, watching television on a flat screen, using their laptop at a cafe, getting better medical care, flying on vacations, living in modern homes and working jobs that require technology. This is happening across the planet! Can you imagine the impact on demand for rare industrial metals from countries of the BRIC, (Brazil, Russia, India, China), with the size of their populations? Like it or not commercialization was tested in the USA and was a huge success and now it has been exported worldwide. Here in Panama with a population of just over 3 Million we are adding 3000 automobiles a month to the roads. There are enough mobile phones in Panama to give every citizen 3 handsets. All of this takes a lot of natural resources and metals. Below are some of the important metals I would like to introduce to you.
Tantalum, the rare technical and industrial metal that gives technology the ability to be compact. Have you ever wondered why we no longer have to carry around mobile phones the size of a brick? The tantalum capacitor was a revolutionary invention for the world. Today you find tantalum in all of your personal electronics. Tantalum is now being used in in medical implants because it is non-toxic and does not react with body fluids. It is also used in jet aircraft as an alloying agent. Current worldwide production of tantalum is approximately 1160t annually. By 2030 just the demand is estimated to be 1410t. A few years back there was a lot of controversy surrounding tantalum because of its “Conflict Metal” tag. The metal was originally being mined in the Congo but most tantalum is mined in Australia, Brazil, and Canada.
Indium, how do you like that touch screen on your mobile phone? This rare technical and industrial metal has become a star among the elements recently. Indium’s uses in phones, computers, semi-conductors and televisions are well known. The one use that I would really like to highlight is in CIGS (copper-indium-gallium-selenide) thin film solar cells. These solar panels are the latest technology to hit the solar industry. Recently we have heard India, Japan, USA, Germany, Spain and many other countries announce huge solar initiatives. India alone signed into law a US $19 billion plan to produce 20 GW of solar power by 2020. Under the plan, the use of solar-powered equipment and applications would be made compulsory on all government buildings, as well as hospitals and hotels. This initiative alone will use up all the entire world’s production of solar cells. According to the USGS 84% of all indium production is currently used in solar cell production. Current worldwide production of Indium is approximately 600t per year. The future amount of indium required will depend greatly on the solar industry. Indium is mined in China, Canada, Bolivia and Japan.
Cobalt, have you driven a hybrid or electric vehicle lately? This rare technical and industrial metal is the one of the elements that makes the batteries in these cars possible. Cobalt is also used in pigments, super-alloys, non-corrosive medical implants, dental implants and jet engines. The top use today is as an alloy to make metals resistant to corrosion. The one I see real promise in is the use of hybrid and electric vehicle batteries. By 2012 the estimated sales of hybrid vehicles worldwide is approximately 2.2 Million and by 2015 to be at least 10% of the world auto market. Currently the biggest hurdle to these vehicles is the added cost and the ability to produce enough batteries to meet the demand. Cobalt has gained a lot of attention since the London Metal Exchange (LME) launched a cobalt contract in February 2010. Current worldwide production of cobalt is approximately 57,500t annually. The future is bright for cobalt. Every aircraft that goes in the air and every hybrid vehicle sold will put greater pressure on the supply of this metal. Cobalt is mined in Australia, Congo, Russia, Zambia and a few other countries.
These are just a few of the metals that our world needs to operate and the future is looking great for all commodities. I like the rare technical and industrial metals because of the tight supply and all of the wonderful uses for them. The mining of these metals is often a by-product of base metal like copper, lead and zinc. Most of the large deposits have been found and are in production. This translates into a very tight supply for the future and profits for investors. Silver and Gold have been my metals of choice for many years, but I see great opportunity for the person who is adventurous and willing to add another asset to their portfolio before the masses catch on.
By: Randy Hilarski - The Rare Metals Guy
Source: http://www.buyrareearthmetalschinaprices.com
Thin-film PV comes one step closer to rivaling crystalline PV in efficiency
“The significance of the modules tested at NREL is that they’re all done on the product line,” said Stephen Barry, vice president of corporate development at MiaSolé.
The news, he said, comes on the heels of MiaSolé’s announcement of modules rated at 14.3 percent efficiency in September 2010. The goal is to achieve a CIGS module that is as efficient as the most powerful CIGS cells tested at NREL,
“We believe there’s more headroom there [for efficiency increases],” he said.
“This is a very exciting result, especially when it comes so soon after the previous 14.3 percent achievement from last September,” NREL solar researcher Dr. Rommel Noufi said in a press release. “An almost 1.5 percent absolute increase in efficiency in such a short time on a continuous roll-to-roll manufacturing line is impressive and demonstrates good process control and a validation of the MiaSolé approach.”
At present, because thin-film PV is behind crystalline silicon PV in terms of efficiency, it need more space to produce electricity. Therefore, most thin-film PVs available today are being used in large-scale applications like commercial warehouses and solar farms and not for residential purposes. As firms like MiaSolé close that efficiency gap, they will likely become more suitable for residential installations. Barry realizes this and said that the application of their product will change as they gain ground with efficiency.
Thin-film PV also allows for more flexibility in design and use.
For instance, MiaSolé’s modules are deposited on a flexible steel substrate, which makes them physically flexible, something that crystalline silicon panels can’t achieve. However, at present, they’re encapsulated in glass, Barry said. But the company has an active building-integrated PV program, he said. And in the future, its PV materials could take the form of roofing for instance.
Don’t expect the 15.7 percent efficient module on the shelf at your neighborhood PV store tomorrow, however.
“We have our MR-107, a 10.5 percent efficient module,” said Barry. “We’re shipping those now in volumes. We have submitted to UL a 13 percent efficient module.”
He said the 13-percent efficient modules will be in production in the second quarter, and couldn’t estimate when the new, more powerful modules would reach commercial availability.
