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    • Bradford White Buys GeoSpring Rights and Equipment February 21, 2017
      Subtitle:  Bradford White will begin making its own line of heat-pump water heaters after buying production equipment from GE Appliances Images:  Bradford White will pick up where GE Appliances left off as it buys the production equipment GE used to make the GeoSpring heat-pump water heaterAn appliance that uses an air-source heat pump to heat […]
      ScottG
    • California Gets New Water Conservation Rules February 17, 2017
      Subtitle:  A law that took effect at the start of the year requires water-conserving fixtures in single-family homes built before 1994 Images:  A state law that became effective at the beginning of the year requires that all plumbing fixtures in houses built before 1994 meet water conservation standards, theoretically pushing many thousands of residents to […]
      ScottG
    • Solar Jobs Are Booming February 16, 2017
      Subtitle:  One of every 50 jobs created in the U.S. last year was in the solar industry, while installed solar capacity nearly doubled in one year Images:  More than 260,000 workers in the U.S. have found employment in the solar industry, with 51,000 jobs added to the workforce in 2016 alone, according to a new […]
      ScottG
    • Next Generation Spray Foams Trickle into the Market February 9, 2017
      Subtitle:  The blowing agent used in new closed-cell formulations will contribute far less to global warming than the chemistry it replaces Images:  UPDATED on Feb. 9, 2017 Reformulated versions of spray polyurethane foam with only a tiny fraction of the global warming potential of their predecessors are getting easier to find. Texas-based Demilec, a manufacturer […]
      ScottG
    • Walmart Fined in Greenwashing Case February 7, 2017
      Subtitle:  According to a group of district attorneys in California, labels on plastic products were misleading to consumers Images:  The case against the country's biggest retailer involved labels on plastic products that erroneously claimed the products were biodegradable or compostable, according to an article posted by Plastic News. read more
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    • Solar Panels Near Break-Even Point February 2, 2017
      Subtitle:  A new study examines the question of when photovoltaic modules settle their 'carbon debt' and become clean energy producers Images:  More efficient manufacturing processes have steadily reduced the amount of energy required to make photovoltaic(PV) Generation of electricity directly from sunlight. A photovoltaic cell has no moving parts; electrons are energized by sunlight and […]
      ScottG
    • Boston Mulls a New Template for Urban Housing February 1, 2017
      Subtitle:  A collaborative pitches small modular housing as a way to align the city's housing stock with what residents need Images:  A Boston startup is proposing a new housing model designed to solve a fundamental problem with urban apartments — they're too big. The company, Livelight, and architect Tamara Roy developed a model for very […]
      ScottG
    • Tackling the Skilled Labor Shortage January 27, 2017
      Subtitle:  Fine Homebuilding magazine joins efforts to bolster training and trade opportunities with a Keep Craft Alive campaign Images:  Fine Homebuilding magazine has launched an effort to help reverse a decline in skilled labor, a trend that is threatening the construction industry and making it harder for homeowners to find qualified contractors. read more
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    • An Aging Solar Star Eases into Retirement January 25, 2017
      Subtitle:  Entries in the Solar Decathlon design competitions get a brief time in the spotlight before they are put out to pasture — and sometimes turned into actual dwellings Images:  It looks like a cross between a classic roadside diner and an Airstream travel trailer, but in its day the Michigan Solar House Project was […]
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    • Dutch Firm Creates a House of Cardboard January 18, 2017
      Subtitle:  Layers of cardboard wrapped around a form produce a house its designers promise will last for at least 50 years Images:  Dutch entrepreneurs have discovered you can do more with corrugated cardboard than make boxes. A Dutch firm called Fiction Factory has developed a modular building system based on segments of glued-up cardboard. Developers […]
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SOLAR CELL BREAKTHROUGH: U of T-led research team develops next-generation CQD solar cells

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CQD solar cells

CQD solar cellsResearchers from the University of Toronto and King Abdullah University of Science & Technology have made a breakthrough in the development of colloidal quantum dot (CQD) films, leading to the most efficient CQD solar cell ever. Their work is featured in a letter published in Nature Nanotechnology.

The researchers, led by U of T Engineering Professor Ted Sargent, created a solar cell out of inexpensive materials that was certified at a world-record 7.0% efficiency.

“Previously, quantum dot solar cells have been limited by the large internal surface areas of the nanoparticles in the film, which made extracting electricity difficult,” said Dr. Susanna Thon, a lead co-author of the paper. “Our breakthrough was to use a combination of organic and inorganic chemistry to completely cover all of the exposed surfaces.”

Quantum dots are semiconductors only a few nanometres in size and can be used to harvest electricity from the entire solar spectrum – including both visible and invisible wavelengths. Unlike current slow and expensive semiconductor growth techniques, CQD films can be created quickly and at low cost, similar to paint or ink. This research paves the way for solar cells that can be fabricated on flexible substrates in the same way newspapers are rapidly printed in mass quantities.

The U of T cell represents a 37% increase in efficiency over the previous certified record. In order to improve efficiency, the researchers needed a way to both reduce the number of “traps” for electrons associated with poor surface quality while simultaneously ensuring their films were very dense to absorb as much light as possible. The solution was a so-called “hybrid passivation” scheme.

“By introducing small chlorine atoms immediately after synthesizing the dots, we’re able to patch the previously unreachable nooks and crannies that lead to electron traps,” explained doctoral student and lead co-author Alex Ip. “We follow that by using short organic linkers to bind quantum dots in the film closer together.”

Work led by Professor Aram Amassian of KAUST showed that the organic ligand exchange was necessary to achieve the densest film.

“The KAUST group used state-of-the-art synchrotron methods with sub-nanometer resolution to discern the structure of the films and prove that the hybrid passivation method led to the densest films with the closest-packed nanoparticles,” stated Professor Amassian.

The advance opens up many avenues for further research and improvement of device efficiencies, which could contribute to a bright future with reliable, low cost solar energy.

According to Professor Sargent, “Our world urgently needs innovative, cost-effective ways to convert the sun’s abundant energy into usable electricity. This work shows that the abundant materials interfaces inside colloidal quantum dots can be mastered in a robust manner, proving that low cost and steadily-improving efficiencies can be combined.”

SOURCE: EurekAlert!

July 31, 2012 |

WIDESPREAD SOLAR: Berkeley lab develops technology to make photovoltaics out of any semiconductor

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Berkeley Lab develops photovoltaics from any semiconductor

Alex Zettl (left) and Will Regan can make low-cost, high efficiency solar cells from virtually any semiconductor material.

A technology that would enable low-cost, high efficiency solar cells to be made from virtually any semiconductor material has been developed by researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley. This technology allows for plentiful, relatively inexpensive semiconductors, such as metal oxides, sulfides and phosphides that had previously been considered unsuitable for solar cells because of the difficulty in tailoring their properties by chemical means.

“It’s time we put bad materials to good use,” says physicist Alex Zettl, who led the research along with colleague Feng Wang. “Our technology allows us to sidestep the difficulty in chemically tailoring many earth abundant, non-toxic semiconductors and instead tailor these materials simply by applying an electric field.”

Zettl, who holds joint appointments with Berkeley Labs’ Materials Sciences Division and UC Berkeley’s Physics Department where he directs the Center of Integrated Nanomechanical Systems (COINS), is the corresponding author of a paper describing this work in the journal Nano Letters. The paper is titled “Screening-Engineered Field-Effect Solar Cells.” Co-authoring it were William Regan, Steven Byrnes, Will Gannett, Onur Ergen, Oscar Vazquez-Mena and Feng Wang.

Solar cells convert sunlight into electricity using semiconductor materials that exhibit the photovoltaic effect–meaning they absorb photons and release electrons that can be channelled into an electrical current. Photovoltaics are the ultimate source of clean, green and renewable energy but today’s technologies utilize relatively scarce and expensive semiconductors, such as large crystals of silicon, or thin films of cadmium telluride or copper indium gallium selenide, that are tricky or expensive to fabricate into devices.

“Solar technologies today face a cost-to-efficiency trade-off that has slowed widespread implementation,” Zettl says. “Our technology reduces the cost and complexity of fabricating solar cells and thereby provides what could be an important cost-effective and environmentally friendly alternative that would accelerate the usage of solar energy.”

This new technology is called “screening-engineered field-effect photovoltaics,” or SFPV, because it utilizes the electric field effect, a well understood phenomenon by which the concentration of charge-carriers in a semiconductor is altered by the application of an electric field. With the SFPV technology, a carefully designed partially screening top electrode lets the gate electric field sufficiently penetrate the electrode and more uniformly modulate the semiconductor carrier concentration and type to induce a p-n junction. This enables the creation of high quality p-n junctions in semiconductors that are difficult if not impossible to dope by conventional chemical methods.

“Our technology requires only electrode and gate deposition, without the need for high-temperature chemical doping, ion implantation, or other expensive or damaging processes,” says lead author William Regan. “The key to our success is the minimal screening of the gate field which is achieved through geometric structuring of the top electrode. This makes it possible for electrical contact to and carrier modulation of the semiconductor to be performed simultaneously.”

SFPV technology

The SFPV technology was tested for two top electrode architectures: (A) the top electrode is shaped into narrow fingers; (B) top electrode is uniformly ultrathin.

Under the SFPV system, the architecture of the top electrode is structured so that at least one of the electrode’s dimensions is confined. In one configuration, working with copper oxide, the Berkeley researchers shaped the electrode contact into narrow fingers; in another configuration, working with silicon, they made the top contact ultra-thin (single layer graphene) across the surface. With sufficiently narrow fingers, the gate field creates a low electrical resistance inversion layer between the fingers and a potential barrier beneath them. A uniformly thin top contact allows gate fields to penetrate and deplete/invert the underlying semiconductor. The results in both configurations are high quality p-n junctions.

Says co-author Feng Wang, “Our demonstrations show that a stable, electrically contacted p-n junction can be achieved with nearly any semiconductor and any electrode material through the application of a gate field provided that the electrode is appropriately geometrically structured.”

The researchers also demonstrated the SFPV effect in a self-gating configuration, in which the gate was powered internally by the electrical activity of the cell itself.

“The self-gating configuration eliminates the need for an external gate power source, which will simplify the practical implementation of SFPV devices,” Regan says. “Additionally, the gate can serve a dual role as an antireflection coating, a feature already common and necessary for high efficiency photovoltaics.”


This research was supported in part by the DOE Office of Science and in part by the National Science Foundation.

Lawrence Berkeley National Laboratory (Berkeley Lab) addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.

SOURCE: EurekAlert!

July 29, 2012 |

LEED MANAGEMENT SOFTWARE: Greengrade adds LEED Canada rating systems to its software

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Des Moines, IAGreengrade–LEED Management SoftwareTM, a division of Textura ® Corporation, announces the addition of LEED Canada to its available LEED-supported rating systems.

Project teams seeking LEED certification via the Canada Green Building Council (CaGBC) can now utilize Greengrade–LEED Management Software to assist in streamlining the CaGBC certification process, saving time and cutting costs associated with traditional LEED administration practices. Greengrade can be utilized for all CaGBC rating systems.

Cobalt Engineering, a member of Integral Group and a leading building services consulting firm, recently selected Greengrade to manage its projects seeking certification under CaGBC’s LEED-NC 2009. Cobalt has experience with more than 90 projects that have recently completed or are currently undergoing LEED certification and has offices across Canada and the US. Kim McClymont, LEED Services Coordinator with Cobalt explains, “We were looking for a new system; a way to simplify the existing process. Keeping communication streamlined and efficient between team members and keeping the project moving forward are essential. Greengrade features that are especially valuable are those saving us from onerous administrative tasks. It will eliminate rote paperwork, thus freeing up time and resources to allow for more meaningful contributions to sustainable design.”

“We also work on both CaGBC and USGBC projects; therefore, having the same system in place to manage both types of projects as a best practice will have a significant impact on enhancing our LEED services,” continued McClymont.

Mike Stuart, President of Greengrade said, “One of our main goals at Greengrade is to help those managing the LEED certification process be efficient and profitable. Expanding our system to include LEED Canada rating systems provides access for companies working in Canada to implement best practices and achieve new levels of efficiency and profitability.”

July 24, 2012 |

NPULP: Straw-pulp for paper making is now a reality

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WASHINGTON, D.C. — As a concept, NPulp—the revolutionary straw-pulp technology developed by Taiwan-based YFY Corp.—is the type of feel good sustainability story that attendees of the 16th Annual Green Chemistry & Engineering Conference in Washington, D.C. want to hear more about.

Why wouldn’t sustainability advocates, business managers and policy makers appreciate an innovative chemical process that converts a naturally abundant resource (straw) into pulp for paper making, a process that requires less energy and greatly reduces the amount of greenhouse gases produced?  In addition, the technology creates new revenue streams and economic development opportunities for local farmers and their communities.

After more than 10 years of research and development, YFY Corp. has successfully moved NPulp from green chemistry concept to reality.  The product and related economic sustainability program debut next month in China’s farm communities, where the straw will be collected and converted into straw pulp.

Through bio-pulping – a proprietary enzymatic process that eliminates the use of harsh chemicals when converting straw to straw pulp – YFY Corp. plans to take advantage of the more than 600 million tons of agricultural straw biomass available in China.  That represents a potential supply of 345 million tons of biopulps, equal to the amount of wood pulp produced globally every year.  In China, under current practices, after farmers harvest their crops, they are left with large amounts of residual straw, of which more than 90% is burned off to clear the fields for more planting.  The burning straw contributes to air pollution and greenhouse gas emissions.

“This is an unprecedented opportunity to show green chemistry in action in ways that benefit all stakeholders,” said Ronald Allen, president of Mobius105, the exclusive distributor of NPulp.  “The burning of straw creates two problems:  massive amounts of greenhouse gas emissions polluting the air and the destruction of a crop that would provide potential incremental revenue to the farmers.  YFY Corp. created a system to collect and purchase the excess straw from farmers in China that discourages burning, protects the environment, brings economic development to rural communities that otherwise wouldn’t have it and provides our customers with the sustainable materials they need.”

Allen is very optimistic about NPulp’s commercial and environmental potential.  He projects the model will be replicated globally, allowing for the expansion and production of straw-based pulp to support local farm communities in other countries.  “The quality of the paper we produce with straw pulp is as good as or better than recycled wood pulp-based paper.  We are already making it ready for use to produce corrugate cardboard, molded cushion packaging and other conventional paper products.”

NPulp is distributed globally by Mobius105, a wholly-owned subsidiary of YFYJupiter, one of Asia’s largest providers of integrated packaging, branding and print management services.  YFYJupiter is majority owned by YFY Corp., a Taiwan-based conglomerate comprised of more than 90 companies that employs more than 10,000 persons worldwide.

July 7, 2012 |
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