A Copper Alliance Member
Edition #16
New Copper Solar Cells Promise a Bright Future
High-resolution version of this photo.
Using renewables in place of carbon-based fuels such as oil and gas offers obvious environmental and even political advantages. However, most of these alternative energy sources are still in development and require subsidies or incentives to become practical. In the case of solar electrical generation, the economics have actually gotten worse, although this situation is poised for a significant turnaround.
Copper and its alloys are vital to energy production, including renewable energy. Copper provides both high heat-transfer capability and superior electrical conductivity, helping to increase the efficiency of all types of systems, from direct-exchange geothermal heat pumps for home heating to today’s high-tech, high-megawatt wind farms.
Solar hot-water systems, which typically include copper tubing and heat exchangers, are familiar to many homeowners. Less well known is that copper is becoming equally valuable in solar-electrical, or photovoltaic (PV) systems. These systems convert sunlight to electricity through silicone-based semiconductors and thin-film materials such as cadmium telluride and gallium arsenide. But the most promising energy-generating material on our solar horizon is copper-indium-gallium-diselenide, or CIGS. A CIGS cell holds the record for the total percentage of energy converted (19.5%) from direct sunlight.
Despite today’s explosive growth in solar power, and increased production of solar cells, the cost of PV power remains high—and continues to rise due to a worldwide shortage of cell-grade silicon. This is where CIGS offers an important advantage. Compared to silicon, which requires multiple manufacturing steps before the material is shaped into individual cell wafers, the CIGS process is relatively energy-efficient, and its technology has advanced to a point where the material can now be deposited as a “coating” on inexpensive strips of material.
According to Scott Albright, director of Advance Programs for Global Solar, located in Tucson, Arizona, CIGS is now cost-competitive with silicon. “And,” he adds, “unit costs will continue to decrease as we begin to take advantage of economies of scale.” Like other CIGS producers, Global Solar is currently expanding its facilities to increase output-the factory here that produced the equivalent of four megawatts (MW/y) of solar units per year will churn out more than 40 MW/y in 2008. The company, which is owned in part by German solar module manufacturer Solon AG, is also expanding its manufacturing operations in Germany.
Industry news service SolarForecast.com notes that a number of companies are currently producing or ramping up to produce CIGS. Global Solar is a leader in CIGS production technology. The company developed an efficient film deposition process that has since become a commercial standard, enabling lower manufacturing costs and faster production than the batch operations formerly used in semiconductor manufacture.
HAVE MODULE, WILL TRAVEL
Global Solar is also the world’s leading flexible PV supplier. These lightweight, portable modules were first adopted by U.S. and foreign armed forces, which needed a reliable power source for the many electronic devices employed by today’s high-tech troops. The company has also created a line of innovative solar products used by outdoor enthusiasts and scientific researchers worldwide.Also in development are rigid, panel-mounted modules suitable for commercial solar farms and home installations. Utilities foresee numerous small solar installations that can be located where energy is needed, as a way to more efficiently distribute electrical power. “That technology is coming,” says Albright, “and that’s where we believe a really significant amount of solar utilization will develop.”
WHY IS COPPER IMPORTANT?
This is not a staged picture! A scientist working in Antarctica needed an environmentally nonintrusive power source to recharge his PDA and laptop batteries. One of Global Solar's portable CIGS modules provided the "green" solution. (Photo courtesy Global Solar Inc.)And that’s just for the power equipment. Electrical installations must be grounded, and here, again, the superior conductivity of copper will undoubtedly be significant. Only copper cables and connectors provide the reliability these systems demand.
Globally, the solar industry is currently growing at a 34% compounded annual rate. If solar energy’s time has finally come, as Scott Albright along with many industrialists and economists now believe, it is certain that the environment, assisted by copper, has a bright future. Cu
This article was adapted from a technical case study posted on the Copper Development Association Web site. For the complete version, see: Copper-based Solar Cells
RESOURCES
Global Solar EnergySolar Forecast Newsletter
Ivy-covered Walls, Copper Roofs Help Keep Tradition Alive
Aerial view of Richardson Hall, a residence hall, (in foreground) and Dartmouth Hall, home to academic offices and classrooms. (Photo provided by Joseph Mehling, Dartmouth College)High-resolution version of this photo.
The $40 million happens to be the price tag for naming a new campus building that will carry their legacy far into the future. The Class of 1978 Life Sciences Center is one of several facilities planned for construction on the Dartmouth campus over the next few years.
The mammoth, 174,500 square-foot building will take its design cues from the “traditional” architecture of the campus. Identifying features include a brick exterior (with or without ivy), granite base and a handsome, pale-green copper roof to cap off the project, according to Steve Campbell, Dartmouth’s director of Planning, Design and Construction.
Because it can take years for copper to achieve a green patina—a natural barrier that protects the metal and contributes to its legendary lifespan—the new building’s roof will be prepatinated before installation, a process that accelerates the color change. This will allow the structure to more quickly blend into its surroundings.
Copper is visible on most of the roofs across the Dartmouth campus. Originally, slate was predominantly used, but the university gradually transitioned to copper through building additions and renovations. “Copper just seems to fit well with our architecture,” explains Jack Wilson, Associate Director of Planning.
Wilson is responsible for selecting architectural materials for Dartmouth. While the college does not have specific architectural guidelines, he feels the campus buildings in general adhere to two existing, predominant styles: neoclassical and neo-Georgian. “You’ll find copper on all the pitched roofs on campus,” he says. “It really sets the tone.”
Within its exterior of copper and brick, the new Life Sciences Center will house an array of laboratories and specialty classrooms that support Dartmouth’s commitment to biological research. Included in the structure are features such as a 200-seat auditorium, two-story atrium, 30 “wet” labs, six teaching labs, two 80-seat amphitheater classrooms and a 6,000 square-foot greenhouse.
Elevation drawings of the new Class of 1978 Life Sciences Center building.High-resolution version of this photo.
Appropriate to its mission, the Life Sciences Center will be environmentally friendly. The building is expected to consume only half of the energy typically required to operate similar laboratories currently in use in the United States. State-of-the-art energy management and stormwater management systems are key features included in the design.
The project is estimated to cost $93 million when it is completed. The class of ’78 is planning to tour their newly named building sometime around March 2010, the proposed opening date.
“The class of ’78 is not only extraordinarily generous, but farsighted in enabling the work of students and faculty in critical fields such as life sciences," says Dartmouth president James Wright. “I’m excited by the prospect of having a building that not only is on the (architectural) cutting-edge for the space it provides, but will also be a national model of sustainable design.” Cu
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Dartmouth College Back to TopA 21st Century Coppersmith
Photo of a copper frieze and curved gutter on Las Vegas home. (Photo courtesy of Hans Liebscher)High-resolution version of this photo.
“Some of the buildings were burned out, and only their shells were standing,” Liebscher recalls. “But for a lot of them, the copper roofs were still there. They were bright green. Some buildings even had copper still intact on the bay windows. It was really quite fascinating.”
His appreciation for copper eventually grew into a vocation. At age 16, he became an apprentice in the metalsmith trade in his native country and later traveled throughout Europe to hone his skills and learn from other craftsmen.
Today, Liebscher is well-known in the copper industry in America, providing custom designed, handcrafted copper products and as an installer of copper building materials for the high-end residential market throughout the United States. Not long after relocating here from Germany in 1985, he opened a studio, Hans Liebscher Custom Copper Works and Sheet Metal, in San Marcos, California. Most of his signature copper work is done at his own foundry in Mexico. He works with several suppliers of copper in the USA. as well as in Europe.
The homes Liebscher has worked on are showcases for his talent, containing such unique copper features as hand-hammered bathtubs and sinks, standing seam window bays, chimney shrouds and hand-embellished fireplaces, ornate cupolas and dormers, smooth-drawn copper door caps, ornamental fluted downspouts and gutter brackets, gargoyles and copper roof shingles and tiles.
The projects don’t end there. He’s quick to boast that, “if a customer can imagine it, I can create it.”
“All of my intricate projects I do myself,” Liebscher says. “It’s very hard to find qualified help. And I’ve got some trade secrets that I don’t want to give away.”
Photo of a designer hood ornament for an outdoor pizza oven being built for a Las Vegas home. (Photo courtesy of Hans Liebscher)High-resolution version of this photo.
Currently, he’s working on three very intricate copper projects for luxury homes in Las Vegas. The work includes ornamental copper gutters and downspouts, radius turret roofs and hand-hammered finials, hand-hammered columns, a handcrafted designer range hood for an outdoor pizza oven and a fireplace hood.
“What people are looking for, most of the time, is the more classical design,” Liebscher says. “They want to recreate the look of buildings from 150 years ago.”
In the desert where there is little humidity, copper products weather to a brownish, nut-like color, rather than the blue-green color associated with moist environments. Regardless, they maintain an equilibrium with nature and remain well preserved, an attribute that helps justify their premium value, Liebscher notes. “If copper is installed right, it’s essentially maintenance-free and will last for hundreds of years. It doesn’t need to be painted and it ages gracefully. It doesn’t disintegrate with age, but becomes more prestigious, more beautiful.”
Over the years, Liebscher has worked on historic renovation projects in Berlin, helped restore the Griffith Observatory in Los Angeles and was instrumental in saving or replacing copper aspects of other landmark buildings such as the Cotton Exchange, which was damaged by Hurricane Katrina in New Orleans.
“Copper is one of the oldest existing materials, and it has always had a good reputation,” Liebscher says. “In some ways, copper has the same value as gold, because it was only found in prestigious and luxury buildings and lasted for centuries.” Cu
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Hans Liebscher Custom Copper Works and Sheet MetalDiet and Depression
High-resolution version of this photo.
Nutrient imbalances can play tricks with the mind and lead to irritability, anger, stress, memory loss and depression, according to the Health Research Institute and Pfeiffer Treatment Center. Two key nutrients that are important in controlling these feelings are zinc and copper.
Zinc is a building block for more than 80 enzymes that directly affect brain activity. Copper, however, works differently. It helps to convert dopamine, a chemical produced by the body and used in brain function, into norepinephrine, which is associated with heightened alertness and mood elevation. The results of this conversion can be pleasant—but too much can lead to overstimulation, hyperactivity and depression.
This problem may be harder for women to control because estrogen, a female hormone, increases the body’s absorption of copper. Several studies have focused on nutrient imbalances and their link to post-partum depression, as well to general depression in both men and women.
These studies typically use blood copper as an indicator of copper status, and elevated blood copper is interpreted to be an indication of an elevated “copper load” in the body. However, high levels of copper in blood are completely independent of the copper level in the body. Copper has often been implicated in certain pathologic conditions, including post-partum depression, based upon the incorrect assumption that the amount of copper in your blood indicates the amount of copper in your body. In fact, copper in your blood is a good indicator of an active immune defense.
For example, when you have a flu or cold, the level of copper in your blood will triple, although—on the whole—you have no more or no less copper in your body. Therefore, be cautious when you consider making a correlation between elevated levels of copper in your blood and elevated levels of copper in your body. The science many times tells us otherwise.
The best way to ensure proper nutrition and a healthy body is to maintain a balance of copper and zinc in your diet. Keep in mind that too much zinc inhibits the body’s ability to absorb copper. According to the National Academy of Sciences, a proper daily balance for adults is: copper, 0.9 mg (male and female); and zinc, 11 mg (males), 8mg (females). Cu
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Health Research InstituteThe information presented in Discover Copper is provided by the Copper Development Association for editorial re-use. This material is verifiable and accurate as of the date of publication. Additional comment, contact information or attribution may be obtained from the sources noted, or by contacting CDA Communication Manager (Victoria Prather). The Copper Development Association Inc., 260 Madison Avenue, New York, NY 10016, is affiliated with the International Copper Association and is the information, education, market and technical development arm of the copper, brass and bronze industry in the United States.
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Edition #16
New Copper Solar Cells Promise a Bright Future
