Concrete may absorb more carbon dioxide than earlier estimates suggested

Many scientists currently think at least 5 percent of humanity's carbon footprint comes from the concrete industry, both from energy use and the carbon dioxide (CO2) byproduct from the production of cement, one of concrete's principal components.

Yet several studies have shown that small quantities of CO2 later reabsorb into concrete, even decades after it is emplaced, when elements of the material combine with CO2 to form calcite.

A study appearing in the June 2009 Journal of Environmental Engineering suggests that the re-absorption may extend to products beyond calcite, increasing the total CO2 removed from the atmosphere and lowering concrete's overall carbon footprint.

While preliminary, the research by civil and environmental engineering professor Liv Haselbach of Washington State University re-emphasizes findings first observed nearly half a century ago--that carbon-based chemical compounds may form in concrete in addition to the mineral calcite-now in the light of current efforts to stem global warming.

"Even though these chemical species may equate to only five percent of the CO2 byproduct from cement production, when summed globally they become significant," said Haselbach. "Concrete is the most-used building material in the world."

Researchers have known for decades that concrete absorbs CO2 to form calcite (calcium carbonate, CaCO3) during its lifetime, and even longer if the concrete is recycled into new construction--and because concrete is somewhat permeable, the effect extends beyond exposed surfaces.

While such changes can be a structural concern for concrete containing rebar, where the change in acidity can damage the metal over many decades, the CaCO3 is actually denser than some of the materials it replaces and can add strength.

Haselbach's careful analysis of concrete samples appears to show that other compounds, in addition to calcite, may be forming. Although the compounds remain unidentified, she is optimistic about their potential.

"Understanding the complex chemistry of carbon dioxide absorption in concrete may help us develop processes to accelerate the process in such materials as recycled concrete or pavement. Perhaps this could help us achieve a nearly net-zero carbon footprint, for the chemical reactions at least, over the lifecycle of such products."

That is the thrust of Haselbach's current NSF-funded work, where she is now looking at evaluating the lifecycle carbon footprint of many traditional and novel concrete applications, and looking for ways to improve them.

"This work is part of the portfolio of studies that NSF is funding in this vital area," added Bruce Hamilton, director of NSF's environmental sustainability program and a supporter of Haselbach's work. "Research relating to climate change is a priority."

-NSF-

April, 2009-  In Bruce Logan's Lab at Penn State, Shaoan Cheng and Defeng Xing work with cell that produces methane directly from electricity by way of tiny microbes. A tiny microbe can take electricity and directly convert carbon dioxide and water to methane, producing a portable energy source with a potentially neutral carbon footprint, according to a team of Penn State engineers.

"We were studying making hydrogen in microbial electrolysis cells and we kept getting all this methane," said Bruce E. Logan, Kappe Professor of Environmental Engineering, Penn State. "We may now understand why."

Methanogenic microorganisms do produce methane in marshes and dumps, but scientists thought that the organisms turned hydrogen or organic materials, such as acetate, into methane. However, the researchers found, while trying to produce hydrogen in microbial electrolysis cells, that their cells produced much more methane than expected.

"All the methane generation going on in nature that we have assumed is going through hydrogen may not be," said Logan. "We actually find very little hydrogen in the gas phase in nature. Perhaps where we assumed hydrogen is being made, it is not."

Microbial electrolysis cells do require an electrical voltage to be added to the voltage that is produced by bacteria using organic materials to produce current that evolves into hydrogen. The researchers found that the Archaea, using about the same electrical input, could use the current to convert carbon dioxide and water to methane without any organic material, bacteria or hydrogen usually found in microbial electrolysis cells. They report their findings in this week's issue of Environmental Science and Technology.

"We have a microbe that is self perpetuating that can accept electrons directly, and use them to create methane," said Logan.

Logan, working with Shaoan Cheng, senior research associate; Defeng Xing, post doctoral researcher, and Douglas F. Call, graduate student, environmental engineering, confirmed that the microscopic organisms produced the methane. The researchers created a two-chambered cell with an anode immersed in water on one side of the chamber and a cathode in water, inorganic nutrients and carbon dioxide on the other side of the chamber. They applied a voltage, but recorded only a minute current. The researchers then coated the cathode with the biofilm of Archaea and not only did current flow in the circuit, but the cell produced methane.

"The only way to get current at the voltage we used was if the microbes were directly accepting electrons," said Logan. He notes that the electrochemical reaction takes place without any precious metal catalysts and at a lower energy level than converting carbon dioxide to methane using conventional, non-biological methods.

The cells are about 80 percent efficient in converting electricity to methane and because they use carbon dioxide as feed stock, would be carbon neutral if the electricity comes from a non-carbon source such as solar or wind power.

"The process does not sequester carbon, but it does turn carbon dioxide into fuel," said Logan. "If the methane is burned and carbon dioxide captured, then the process can be carbon neutral."

Logan suggests the method for off peak capture of renewable energy in a portable fuel. Methane is preferred over hydrogen because a large portion of the U.S. infrastructure is already set up to easily transport and deliver methane.

The National Science Foundation and Air Products and Chemicals, Inc. supported this project.

http://live.psu.edu/story/38671

Novozymes has cut cellulosic ethanol enzyme costs by more than half and is on track to deliver the first commercially viable enzymes by 2010 – an important step on the way to enabling the commercial success of cellulosic ethanol.

At the National Ethanol Conference in San Antonio in Texas, Executive Vice President Peder Holk Nielsen presented the progress achieved by Novozymes’ latest second-generation enzyme products. This new enzyme family is the highest performing and most cost-effective enzyme solution available today.

Technology ready – Implementation needed

The Renewable Fuel Standard (RFS) requires the US to blend 100 million gallons of cellulosic ethanol into gasoline in 2010.

“The technology is at a critical point in development, and a wave of US cellulosic plants are ready to be built. However, besides financial aid, the ethanol industry needs strong government support to remove barriers for expanded ethanol use and continued support for the existing RFS volume mandates, which Congress set in the energy law of 2007,” Peder Holk Nielsen explains.

Cellulosic ethanol will continue the greenhouse gas savings trend traditional corn-based ethanol has started with an expected reduction in CO2 emissions of up to 90% compared with oil-based fuels. Due to the RFS the US will prevent 200 million tons of CO2 from being released into the atmosphere every year from 2022 onwards – just by replacing gasoline with ethanol.

Commenting, Peder Holk Nielsen says, “Novozymes has dedicated an unprecedented number of R&D resources focused on enzyme development for cellulosic ethanol. To date, our efforts have successfully reduced the cost of enzymes in many of our partners’ processes by 50%. The results we're achieving in our labs for our next generation of enzymes make us confident that we'll deliver a commercially viable enzyme product to the ethanol industry by 2010 through an additional 50% reduction in enzyme use cost”.

“After thorough testing by our partners in their processes, it's clear that our latest enzyme product family has the best absolute performance and cost/performance ratio in the industry to date. We're breaking through the technical and cost-related barriers with our enzyme technology; due to the success of these trials, Novozymes is now making the product more broadly available in order to help enable further development of cellulosic ethanol.”

Second-generation cellulosic ethanol uses enzymes to break down cellulosic waste materials such as corn stover, sugarcane bagasse, and wood chips into sugars that can be fermented into ethanol. Novozymes’ newest enzyme product family has proven to work on many different feedstock types.

“The technology is getting closer and we're confident that together with key partners we'll soon achieve cellulosic ethanol commercial success. The goal for cellulosic ethanol is to be on par with corn-based ethanol on a cost basis, which we think is feasible within a few years. The cost of cellulosic ethanol production will go down as we and our partners go up the learning curve,” Peder Holk Nielsen adds.

Source: Novozymes Press Release

--High Efficiency Polymer Solar Cells--

SAN JOSE, CA--Solarmer Energy, Inc. held the first public demonstration of their plastic solar cells at the Printed Electronics Conference in San Jose, CA on December 3rd, 2008. The solar cells generate enough power to drive a small electrical device under bright indoor lighting conditions. The company will also have translucent cells and flexible cells available for examination.

Solarmer's highest efficiency polymer solar cells have demonstrated 6% efficiency, and they plan to seek NREL certification of these results in the near future. While the translucent and flexible cells have not yet attained this level of efficiency, the company's goals are to prove feasibility with these early samples.

"The true distinguishing feature of our technology is our ability to make the solar cells translucent. This quality will allow for very attractive cells in a variety of colors that will enhance the look and feel of any product, opening up a large number of consumer applications for this technology," said Woolas Hsieh, President of Solarmer.

"We are very excited about demonstrating our progress towards commercially viable plastic solar cells," said Dr. Vishal Shrotriya, Solarmer's Director of Technology Development. "With our latest advances, it is easy to see that these cells will be able to power small portable electronic devices in the near future."

At the conference, Dr. Shrotriya  presented Solarmer's progress and plans for pilot scale manufacturing.

About Solarmer Energy, Inc.

Solarmer Energy, Inc. is developing flexible, translucent, light weight plastic solar cells which generate cost-effective, clean energy from the sun. Solarmer's plastic solar cells will create new markets that are currently not addressable with conventional silicon solar cell technology. The first major applications for this technology will likely be portable digital electronic devices (such as cell phones and laptops) and outdoor lifestyle applications. Building Integrated Photovoltaics, Smart Fabrics, and Smart-Networks will soon follow. The company was founded in 2006 to commercialize technology first developed at UCLA. For more information, please visit www.solarmer.com

Next Generation Solar Technology Provides Power and Industrial Steam on Cost-Competitive Basis

Bakersfield, CA—In October, Ausra, Inc. (http://www.ausra.com) and California Governor Arnold Schwarzenegger launched the company's Kimberlina Solar Thermal Energy Plant in Bakersfield, CA, showcasing the company's "next generation" concentrating solar thermal technology.

Governor Schwarzenegger joined Ausra President, CEO and Chairman Bob Fishman, U.S. Reps. Jim Costa (CA-20) and Kevin McCarthy (CA-22), California Assemblymember Jean Fuller and Pacific Gas and Electric (PG&E) CEO Peter Darbee in launching a new era of solar thermal power with the turning of Ausra's large solar thermal mirrors—harvesting California sunshine and creating California jobs.

"This plant proves that our technology is real, it works, and it's ready to power businesses or provide process steam for industries—now," said Fishman. "Ausra is first on the market, providing customers a dependable, cost-effective solar thermal energy system. Some of the best investment minds in the country have backed our technology and our management team's ability to deliver."

At full output, Kimberlina will be able to generate 5 megawatts of electricity, enough to power 3,500 homes in central California. The Kimberlina plant is the first solar plant in the country to utilize Ausra's next generation technology, and it is the first solar thermal power plant of any type built in California in nearly 20 years.

"This next generation solar power plant is further evidence that reliable, renewable and pollution-free technology is here to stay, and it will lead to more California homes and businesses powered by sunshine," said Governor Schwarzenegger. "Not only will this large-scale solar facility generate power to help us meet our renewable energy goals, it will also generate new jobs as California continues to pioneer the clean-tech industry."

The Palo Alto, CA-based company, a large-scale solar thermal energy developer and manufacturer, has dropped solar power's costs by simplifying the design of its systems. This also results in the most land-use efficient solar technology. Ausra has demonstrated its ability to manufacture its systems rapidly with a state-of-the-art factory in Las Vegas, NV that can mass produce Ausra's 1,000-foot mirror lines using standard materials to deploy and scale up quickly. The Kimberlina plant was built in seven months.

In addition to providing reliable, cost-effective electricity, the Kimberlina plant also demonstrates Ausra's ability to provide solar mirror fields for industries that need high-temperature steam for their factories, either as retrofits or as part of new plant construction. A range of industries use this "process steam," including: enhanced oil recovery and oil refining; food processing; and pulp and paper manufacturing.

The Kimberlina facility will also serve as the gateway toward developing Ausra's Carrizo Plains solar power plant. In November 2007, Ausra and California utility Pacific Gas and Electric Company (PG&E) announced a power purchase agreement for the 177-megawatt power plant in central California. When completed, Ausra's Carrizo facility will generate enough electricity to power more than 120,000 homes.

Unlike photovoltaic solar panels, which convert the light from the sun into electricity and are commonly rooftop mounted, solar thermal facilities use large fields of mirrors to concentrate and capture the sun's heat, converting it into useful forms of energy. In Ausra's technology, heat is focused on tubes of water to create steam that drives large power turbines, generating clean, reliable electricity and high-temperature, "process" steam for industrial applications.

About Ausra, Inc.

Ausra delivers energy from the sun. The company provides solar power, steam and energy systems for industrial processes and utility-scale electricity generation. The company is a leader in solar thermal energy design, development and manufacturing, and is committed to serving the global energy needs of its customers in a dependable, market-competitive and environmentally responsible manner. Headquartered in Palo Alto, Calif., Ausra is a privately held company with operations in the United States and Australia. To learn more about Ausra and solar thermal energy, visit www.ausra.com.

Low Cost Solar Printing Process Garners Honor from “Oscars of Invention”

A simpler, faster end-to-end process for printing high quality thin film photovoltaic (PV) systems

Austin, Texas – October 23, 2008 – Solar thin film manufacturer HelioVolt Corporation and the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) were awarded the Editor’s Choice Award for Most Revolutionary Technology from R&D Magazine at a gala award event held in Chicago last week. The Editor’s Choice honor was bestowed in addition to a previously announced R&D 100 Award, both garnered for the organizations’ joint achievements in developing a simpler, faster end-to-end process for printing high quality thin film photovoltaic (PV) systems. Pairing NREL’s ink jet deposition technique with HelioVolt’s FASST® printing process, the manufacturing advancements are designed to lower the cost of generating clean electricity from the sun.

“These lower cost paths to high quality photovoltaic products enable a fundamental shift in our electricity mix from traditional, polluting sources to renewable energy harnessed from the sun. I am proud that our collaborative work with NREL was highlighted by the R&D editors, not only for the innovative nature of the research but also its very real commercial and environmental potential,” said Dr. Louay Eldada, HelioVolt’s chief technical officer.

“Over the last three decades, researchers and others have envisioned a time when we might be able to do something as simple, fast, and inexpensive as constructing our houses and buildings with PV-coated materials to provide the electricity the buildings would need,” said R&D editor in chief Martha Walz. “That vision will soon be a reality thanks to this low cost solar printing process developed by HelioVolt and NREL.”

“Thin film PV technology is already impacting the energy industry by significantly lowering the cost of generating electricity from the sun with the use of less materials, " said NREL Director Dan Arvizu. "Public and private sector collaboration speeds up the time it takes to move these new technologies into the marketplace and we are pleased to share this national recognition with HelioVolt."

HelioVolt’s FASST reactive transfer printing process drives cost advantages by manufacturing high-quality CIGS thin film products ten to one hundred times more rapidly than competitive methods. FASST can be combined with vacuum evaporation, ultrasonic spray, or ink-jet printing deposition processes like the one developed by NREL, allowing for industry-leading flexibility to achieve the lowest cost process. Confirmed through independent testing, FASST delivers solar cells exceeding 12 percent conversion efficiency in a record setting six minutes. These efficiencies place HelioVolt's CIGS devices among the highest performing solar thin film products on the market today. HelioVolt is using FASST to develop both conventional modules and next-generation building integrated photovoltaic (BIPV) products for the global solar energy market. HelioVolt will employ FASST for commercial production for the first time at a factory set to open later this week in Austin, Texas.

About HelioVolt

HelioVolt Corporation was founded in 2001 in order to develop and market new technology for applying thin-film photovoltaic coatings to conventional construction materials. The company’s proprietary FASST® process, based on semiconductor printing, was invented by HelioVolt founder Dr. Billy J. Stanbery, an eminent expert within the international PV community in the materials science of CIGS and related compound semiconductors.  FASST® is a low-cost, flexible manufacturing process for CIGS synthesis and is protected by both fifteen issued US and foreign national patents and by numerous additional global patents pending.  For additional information, visit www.heliovolt.com.

“Green Gasoline”

What is Green Gasoline?

• Green gasoline is a mixture of chemical compounds that is nearly identical to standard gasoline, yet it comes from plants, not petroleum.
• Researchers around the world are working on different approaches to creating green gasoline. The tools range from microbes to catalysts (materials that speed up reactions without sacrificing themselves in the process), with each approach having its own advantages and disadvantages.
• Scientists and engineers using catalysts have made a number of recent breakthroughs, including conversion of wood chips into high-octane fuel components and the conversion of sugar (potentially derived from plants) into gasoline, diesel and jet fuel materials and precursors for pharmaceuticals and plastics.
• There are three main catalytic mechanisms to convert plants into gasoline:

1. Gasification is one of the oldest mechanisms to make gasoline from non-petroleum sources, but since it had primarily been used to convert coal or natural gas into gasoline, it is only now finding applications as a green gasoline process. In gasification, extreme heat breaks the plants down to the fundamental components of carbon monoxide (CO) and hydrogen (H₂). The gasses are passed over catalysts which grab the CO and H₂, and depending on which catalysts are used, recombines them into gasoline. The process is well-established but is currently only feasible at large scales. It is expensive and not efficient when plants are the feedstock.
2. Pyrolysis is also a mechanism that uses heat, but it uses less than gasification, and like all of the catalytic approaches (including the method used in George Huber's laboratory at the University of Massachusetts Amherst) it is so efficient that it does not require any external energy source. Researchers even hope to eventually use the heat produced by the pyrolysis process to generate electricity. While new for green gasoline applications, the process has a number of advantages in that it can use any plant starting material, including waste paper and grass clippings, and is efficient. So far, the process can produce components of gasoline, but not yet the full suite of components found in transportation fuels.
3. Aqueous Phase Processing starts with sugar, but sugar is somewhat easily derived from plants. At room temperature, the sugar is mixed with water and passed over specialized catalysts. If the catalysts are properly selected, the end result can be a wide range of substances, from gasoline (all 300-plus chemical components) to diesel to jet fuel to the precursors for pharmaceuticals and plastics. The process, under development at Virent Energy Systems, Inc. in Madison, Wisc. and initially at the University of Wisconsin, Madison, in James Dumesic's laboratory, is currently being scaled up for commercial applications. With buy-in from a number of major industry partners, Virent is hoping to bring this green gasoline process to market within the next five to 10 years.

• The sugar source for aqueous phase processing can come from such plants as sugar beets and sugar cane, and many researchers are devising ingenious ways to create sugars from all the parts of a plant. Some researchers are also working on growing new plants that are easier to convert into sugars.
• Source plants, such as switchgrass, can be grown on marginal lands, so neither food sources nor pristine forests need to be impacted.
• Green gasoline technologies recycle carbon instead of adding net carbon to the atmosphere. The same carbon that comes out of a tailpipe when green gasoline is burned is taken out of the atmosphere by the next crop of green gasoline plants. With non-renewable sources of fuel, the source carbon had been isolated within the Earth, but adds to total atmospheric carbon when it burns.

Source: NSF

 “Green Gasoline” From Sugars and Carbohydrates

Using processes familiar to the petroleum industry, two separate research groups craft "green gasoline" from sugar and carbohydrates

Following independent paths of investigation, two research teams are announcing this month that they have successfully converted sugar-potentially derived from agricultural waste and non-food plants-into gasoline, diesel, jet fuel and a range of other valuable chemicals.

Chemical engineer Randy Cortright and his colleagues at Virent Energy Systems of Madison, Wisc., a National Science Foundation (NSF) Small Business Innovation Research awardee, and researchers led by NSF-supported chemical engineer James Dumesic of the University of Wisconsin at Madison are now announcing that sugars and carbohydrates can be processed like petroleum into the full suite of products that drive the fuel, pharmaceutical and chemical industries.

"NSF and other federal funding agencies are advocating the new paradigm of next generation hydrocarbon biofuels," said John Regalbuto, director of the Catalysis and Biocatalysis Program at NSF and chair of an interagency working group on biomass conversion. "Even when solar and wind, in addition to clean coal and nuclear, become highly developed, and cars become electric or plug-in hybrid, we will still need high energy-density gasoline, diesel and jet fuel for planes, trains, trucks, and boats. The processes that these teams developed are superb examples of pathways that will enable the sustainable production of these fuels."

The process Virent discovered in early 2006, and announced at the Growing the Bioeconomy conference sponsored by Iowa State University on Sept. 9, 2008, is the subject of patent applications published last week.

That announcement was followed this month by the publication of a separate discovery of the same process in the Dumesic laboratory. Dumesic and his colleagues announce their findings in the Sept. 18, 2008 online ScienceExpress, to be followed in print in the Oct. 18, 2008, issue of Science.

The key to the breakthrough is a process developed by both Dumesic and Cortright called aqueous phase reforming. In passing a watery slurry of plant-derived sugar and carbohydrates over a series of catalysts-materials that speed up reactions without sacrificing themselves in the process-carbon-rich organic molecules split apart into component elements that recombine to form many of the chemicals that are extracted from non-renewable petroleum.

According to Dumesic, a key feature of the approach is that between the sugar or starch starter materials and the hydrocarbon end products, the chemicals go through an intermediate stage as an organic liquid composed of functional compounds.

"The intermediate compounds retain 95 percent of the energy of the biomass but only about 40 percent of the mass, and can be upgraded into different types of transportation fuels, such as gasoline, jet and diesel fuels," said Dumesic. "Importantly, the formation of this functional intermediate oil does not require the need for an external source of hydrogen," he added, since hydrogen comes from the slurry itself.

As part of a suite of second generation biofuel alternatives, green gasoline approaches like aqueous phase reforming are generating interest across the academic and industrial communities because they yield a product that is compatible with existing infrastructure, closer than many other alternatives in their net energy yield, and most importantly, can be crafted from plants grown in marginal soils, like switchgrass, or from agricultural waste.

While several years of further development will be needed to refine the process and scale it for production, the promise of gasoline and other petrochemicals from renewable plants has led to broad industrial interest.

Virent's process, called BioForming, is allowing the company to address one of the key goals of NSF's SBIR program, commercialization, and a broader NSF target, American competitiveness. A recent alliance with one of the world's largest energy companies aims to bring these alternative fuels to market, and investment from major automotive and agricultural companies from around the world are broadening the company's impact.

"The early support of NSF helped lay the groundwork for our technical, and subsequent industrial, successes," said Cortright, chief technology officer at Virent. "Our scientists now have years of expertise with our BioForming process and are rapidly moving the technology to commercial scale. We are quickly working to put our renewable, green gasoline and other hydrocarbon biofuels in fuel tanks all over the world."

Added Rose Wesson, the NSF program officer who oversaw Virent's grant, "The technology developed by Virent is extremely promising, and has been refined over the last six years. The aqueous phase reforming process used by both research is an innovative approach that may yield an important, positive impact on the energy demands of the U.S. and worldwide."

On Sept. 23, 2008, at 2:00 p.m., three leading experts from academia and industry, including Randy Cortright and George Huber, both former students of Jim Dumesic, will host a panel discussion at NSF to highlight how far researchers have come, and how far they still need to go, to bring plant-derived gasoline to market. For additional information, see the media advisory at: http://nsf.gov/news/news_summ.jsp?cntn_id=112243.

-NSF-

Principal Investigators
James Dumesic, University of Wisconsin-Madison dumesic@cae.wisc.edu
Randy Cortright, Virent Energy Systems, Inc. randy_cortright@virent.com

--NSF-funded Chemical Bonding Center project provides a new approach for harnessing the sun's energy--

--Caltech scientists are researching converting water and solar energy to hydrogen and oxygen fuels--

View a video of MIT scientists explaining how they recently discovered a catalyst that produces oxygen gas from water.

http://www.nsf.gov/news/news_videos.jsp?cntn_id=112154&media_id=62806&org=NSF

With the assistance of a five-year $20 million award from the National Science Foundation (NSF), the California Institute of Technology (Caltech) Chemical Bonding Center (CBC) project, called "Powering the Planet," will increase the number of its collaborators to fulfill its goal of efficiently and economically converting solar energy and water into hydrogen and oxygen fuels.

The hydrogen and oxygen gases produced will be usable by a fuel cell, where they will react to reform water, generating electricity for powering an electric car or other devices. The gases may also be used as a source of energy after the sun goes down, and will generate a carbon-neutral or oil-free source of energy scalable to meet future global energy demands.

One of the center's key goals is to enhance U.S. economic competitiveness in the area of renewable energy.

"We have a very talented and dedicated group of students who are ready and able to tackle the fundamental chemistry problems that must be solved before it will be feasible to produce clean solar fuels on a large scale," said Harry B. Gray, Arnold O. Beckman professor of chemistry at Caltech and leader of the CBC. "We already have several industrial partners, and we intend to add more, as we want to move the new materials and processes invented by our center into the commercial arena as rapidly as possible."

More than 17 researchers and their students from 12 institutions located throughout the U.S. and Switzerland participate in the CBC.

The center is focusing its research efforts on developing a nanoscale-sized system that captures sunlight and converts it to an electrical charge. The interaction of the system's electrical charge and an oxygen catalyst produce oxygen gas and positively charged hydrogen ions or protons from water. The electrical charge, in combination with a hydrogen catalyst and protons, produces hydrogen gas.

"These transformations will require the development of new models for understanding multiple electron and proton transfer reactions and catalyst design," said Luis Echegoyen, director of NSF's Division of Chemistry.

The center has already obtained significant research results.

Daniel G. Nocera, the Henry Dreyfus professor of energy and professor of chemistry at the Massachusetts Institute of Technology (MIT) and one of the center's collaborators, recently announced that he and his postdoctoral associate, Matthew W. Kanan, successfully developed a new catalyst that produces oxygen gas from water.

In use with an electrical conducting glass electrode, the new catalyst, made from the earth-abundant materials cobalt and phosphate, produces oxygen gas from neutral pH water using a relatively low potential at room temperature and pressure (see video). 

Even though the catalytic reaction is still not yet fully understood, its discovery moves the center one step closer to reaching its goal of using the sun's energy and water as a renewable energy source.

Nocera's and Kanan's research was published in the July 31, 2008, online issue of the journal Science.

"I strongly support Chemistry's CBC program as a way to tackle grand challenge problems with potentially transformative societal impacts such as sustainable energy. The Nocera work and the 'Powering the Planet' Center is an excellent example of this," said Tony Chan, assistant director for NSF's Mathematical and Physical Sciences Directorate.

Phase I of the CBC was established in 2005 when Caltech and MIT were awarded a $1.5 million three-year grant for initial research efforts and for establishing their CBC's management, education, broadening participation and public outreach plans. Caltech's CBC was one of the three Phase I CBCs funded by NSF in 2005 and the only CBC to receive 2008 Phase II funding.

Funding for Caltech's CBC was provided by award 0802907. The CBC is eligible for a $20 million five-year renewal in 2013.

-NSF-

 --Dyed-glass breakthrough channels energy into solar cells--

 An artist's representation shows a cost-effective solar concentrator. An artist's representation shows how a cost-effective solar concentrator could help make existing solar panels more efficient. The dye-based luminescent solar concentrator functions without the use of tracking or cooling systems, greatly reducing the overall cost compared to other concentrator technology. Dye molecules coated on glass absorb sunlight, and re-emit it at a different wavelengths. The light is trapped and transported within the glass until it is captured by solar cells at the edge. Some light passes through the concentrator, and is absorbed by lower voltage solar cells underneath. [Note: Graphic is not to scale.]Credit: Nicolle Rager Fuller, NSF

View a video interview of electrical engineer Marc Baldo of MIT.

http://www.nsf.gov/news/news_videos.jsp?cntn_id=111903&media_id=62588&org=NSF

Revisiting a once-abandoned technique, engineers at the Massachusetts Institute of Technology (MIT) have successfully created a sophisticated, yet affordable, method to turn ordinary glass into a high-tech solar concentrator.

The technology, which uses dye-coated glass to collect and channel photons otherwise lost from a solar panel's surface, could eventually enable an office building to draw energy from its tinted windows as well as its roof.

Electrical engineer Marc Baldo, his graduate students Michael Currie, Jon Mapel and Timothy Heidel, and postdoctoral associate Shalom Goffri, announced their findings in the July 11 issue of Science.

"We think this is a practical technology for reducing the cost of solar power," said Baldo.

The researchers coated glass panels with layers of two or more light-capturing dyes. The dyes absorbed incoming light and then re-emitted the energy into the glass, which served as a conduit to channel the light to solar cells along the panels' edges. The dyes can vary from bright colors to chemicals that are mostly transparent to visible light.

Because the edges of the glass panels are so thin, far less semiconductor material is needed to collect the light energy and convert that energy into electricity.

"Solar cells generate at least ten times more power when attached to the concentrator," added Baldo.

Because the starting materials are affordable, relatively easy to scale up beyond a laboratory setting, and easy to retrofit to existing solar panels, the researchers believe the technology could find its way to the marketplace within three years.

The new technology emerged in part from an NSF Nanoscale Interdisciplinary Research Team effort to transfer the capabilities of photosynthesis to solar technology.

The researchers' approach succeeded where efforts from the 1970s failed because the thin, concentrated layer of dyes on glass is more effective than the alternative--a low concentration of dyes in plastic--at channeling most of the light all the way to the panel edges. However, the current technology still needs further development to create a system that will last the 20- to 30-year lifetime necessary for a commercial product.

For additional information, see the MIT release at: http://web.mit.edu/newsoffice/2008/solarcells-0710.html

Raven Plans to Build Biorefinery to Produce Cellulosic Ethanol From Wood Waste

Raven Biofuels International Corporation plans to build a cellulosic ethanol Biorefinery in Washington State, using a two stage diluted acid hydrolysis. The plant will convert 500 tons per day of wood waste, such as construction and demolition wood or wood chips, and is planned to have a production capacity of almost 11 million gallon per year of ethanol and specialty chemicals (furfural and its derivatives).

The proprietary technology has been developed during the past 10 years and has its origins with the Tennessee Valley Authority, who have been extensively involved in testing programs. Pure Energy Corporation has further developed the technology and protected key elements through patents spending over $20 Million during development. (Raven and Pure Energy have announced their intention to merge on March 13, 2008.)

John Sams, Chief Operating Officer of Raven explains, "The technology is based on simple and proven pulp and paper mill technology, used in the industry for many years successfully. This reduces the risk of commercial deployment and will facilitate a fast roll out of multiple sites in North America."

Raven has chosen Washington State for its substantial availability of feedstock. Both demolition and construction wood and wood waste are available. Moreover, the region is known for its pulp and paper industry. We plan to engage engineering and construction firms that have experience designing and constructing plants using similar technologies.

Recently Gov. Christine Gregoire of Washington State has proposed greater investment by the state in the biofuel industry, calling it "the largest industry of the 21st century and one Washington is well positioned to lead."

The investment in this plant is projected to be $30 Million and construction is expected to take approximately 14 months. Our biorefineries will be financed by equity infusion from Raven and its partners and project finance debt from reputable industry lenders. We assume a project debt financing of $20 Million per plant. The company will likely be eligible to receive additional financial support from grants, loan guarantees, and subsidies from the various programs at the state and federal level.

Revenues of this plant are estimated to be $35 Million when in full production. The payback period is projected to be just over three years from the start of production.

Raven Biofuels International Corporation intends to become a global renewable energy company whose principal focus is converting waste biomass in the low cost production of cellulosic ethanol, and derivative chemicals.

Source: Raven Biofuels International Corp. Press Release
Website: www.ravenbiofuelsinternational.com  

Scanning electron microscope (SEM) image of n-type InP nanowire growth on indium tin oxide (ITO) taken at a 45 degree tilt with scale bar of 500 nanometers. Photo credit: UC San Diego

San Diego, CA, -- University of California, San Diego electrical engineers have created experimental solar cells spiked with nanowires that could lead to highly efficient thin-film solar cells of the future.

Indium phosphide (InP) nanowires can serve as electron superhighways that carry electrons kicked loose by photons of light directly to the device’s electron-attracting electrode – and this scenario could boost thin-film solar cell efficiency, according to research recently published in NanoLetters.

The new design increases the number of electrons that make it from the light-absorbing polymer to an electrode. By reducing electron-hole recombination, the UC San Diego engineers have demonstrated a way to increases the efficiency with which sunlight can be converted to electricity in thin-film photovoltaics.

Including nanowires in the experimental solar cell increased the “forward bias current” – which is a measure of electrical current – by six to seven orders of magnitude as compared to their polymer-only control device, the engineers found.

The online journal NanoLetters published this new work on polymer/nanowire hybrid photovoltaics in February 2008.

“If you provide electrons with a defined pathway to the electrode, you can reduce some of the inefficiencies that currently plague thin-film solar cells made from polymer mixtures. More efficient transport of electrons and holes – collectively known as carriers – is critical for creating more efficient solar cells,” said Clint Novotny the first author of the NanoLetters paper, and a recent electrical engineering Ph.D. from UC San Diego’s Jacobs School of Engineering. Novotny is now working on solar technologies at BAE Systems.

 Simplified Nanowire Growth

 The engineers devised a way to grow nanowires directly on the electrode. This advance allowed them to create the electron superhighways that deliver electrons from the polymer-nanowire interface directly to an electrode.

“If nanowires are going to be used massively in photovoltaic devices, then the growth mechanism of nanowires on arbitrary metallic surfaces is an issue of great importance,” said co-author Paul Yu, a professor of electrical engineering at UC San Diego’s Jacobs School of Engineering. “We contributed one approach to growing nanowires directly on metal.”

The UCSD electrical engineers grew their InP nanowires on the metal electrode – indium tin oxide (ITO) – and then covered the nanowire-electrode platform in the organic polymer, P3HT, also known as poly(3-hexylthiophene). The researchers say they were the first group to publish work demonstrating growth of nanowires directly on metal electrodes without using specially prepared substrates such as gold nanodrops.

“Just a layer of metal can work. In this paper we used ITO, but you can use other metals, including aluminum,” said Paul Yu.

Growing nanowires directly on untreated electrodes is an important step toward the goal of growing nanowires on cheap metal substrates that could serve as foundations for next-generation photovoltaics that conform to the curved surfaces like rooftops, cars or other supporting structures, the engineers say.

“By growing nanowires directly on an untreated electrode surface, you can start thinking about incorporating millions or billions of nanowires in a single device. I think this is where the field is eventually going to end up,” said Novotny. “But I think we are at least a decade away from this becoming a mainstream technology.”

Polymer Solar Cells and Nanowires Meet

As in more traditional organic polymer thin-film solar cells, the polymer material in the experimental system absorbs photons of light. To convert this energy to electricity, each photon-absorbing electron must split apart from its hole companion at the interface of the polymer and the nanowire – a region known as the p-n junction.

Once the electron and hole split, the electron travels down the nanowire – the electron superhighway – and merges seamlessly with the electron-capturing electrode. This rapid shuttling of electrons from the p-n junction to the electrode could serve to make future photovoltaic devices made with polymers more efficient.

“In effect, we used nanowires to extend an electrode into the polymer material,” said co-author Edward Yu, a professor of electrical engineering at UCSD’s Jacobs School of Engineering.

While the electrons travel down the nanowires in one direction, the holes travel along the nanowires in the opposite direction – until the nanowire dead ends. At this point, the holes are forced to travel through a thin polymer layer before reaching their electrode.

Today’s thin-film polymer photovoltaics do not provide freed electrons with a direct path from the p-n junction to the electrode – a situation which increases recombination between holes and electrons and reduces efficiency in converting sunlight to electricity. In many of today’s polymer photovoltaics, interfaces between two different polymers serve as the p-n junction. Some experimental photovoltaic designs do include nanowires or carbon nanotubes, but these wires and tubes are not electrically connected to an electrode. Thus, they do not minimize electron-hole recombination by providing electrons with a direct path from the p-n junction to the electrode the way the new UCSD design does.

Before these kinds of electron superhighways can be incorporated into photovoltaic devices, a series of technical hurdles must be addressed – including the issue of polymer degradation. “The polymers degrade quickly when exposed to air. Researchers around the world are working to improve the properties of organic polymers,” said Paul Yu.

As it was a proof-of-concept project, the UCSD engineers did not measure how efficiently the device converted sunlight to electricity. This explains, in part, why the authors refer to the device in their NanoLetters paper as a “photodiode” rather than a “photovoltaic.”

Having a more efficient method for getting electrons to their electrode means that researchers can make thin-film polymer solar cells that are a little bit thicker, and this could increase the amount of sunlight that the devices absorb.

Paper title: "InP Nanowire/Polymer Hybrid Photodiode" by Clint J. Novotny, Edward T. Yu, and Paul K. Y. Yu from the Department of Electrical and Computer Engineering, University of California, San Diego. Published on the NanoLetters Web site on 02/12/2008

This project is one of the ways UCSD's Jacobs School of Engineering is addressing the National Academy of Engineering Grand Challenge of "Make Solar Energy Economical". Learn more about how UCSD is addressing the NAE Grand Challenges.