Aluminum Metal Advancements in Sustainability

Can the idea of sustainability be determined by metrics?  The answer is “Of course”, as any type of improvement can be measured. We understand it is far more efficient to recycle aluminum than it is to produce it the first time, which we call this value embodied energy.  However, since refining represents a significant proportion of manufactured costs there becomes a premium on recycling used aluminum.  Not only are the savings in energy, they are also in emissions of GHG’s.

Novelis reports.

“Recycling aluminum produces 95 percent fewer greenhouse gas (GHG) emissions and requires 95 percent less energy than primary aluminum production, enabling Novelis to achieve lower GHG emissions despite increasing global production capacity.” (1)

Novelis also reports improvements in Energy Intensity and Water Intensity metrics.

Significant gains were also made in fiscal 2016 as it relates to water and energy intensity. Novelis achieved a 22 percent reduction in water intensity and a 24 percent reduction in energy intensity for the 2007-2009 baseline.  (1)

Novelis Core Business

Novelis produces close to 20 percent of the world’s rolled aluminum products and we are strategically located on the four continents where aluminum demand is the greatest: North America, South America, Europe and Asia. Our dedication, innovation and leadership have made us the number one producer of rolled aluminum in Europe and South America, and the number two producer in North America and Asia. We also are the world’s largest recycler of used beverage cans, which comprise a critical input to our operations. Quite simply, recycling is a core element of our manufacturing process.  (2)

Figure 1:  Novelis Opens World’s Largest Aluminium Recycling Facility (3)

Novelis has officially opened the “world’s largest” aluminium recycling centre located adjacent to the company’s rolling mill in Nachterstedt, Germany and costing over £155m.

The recycling centre will process up to 400,000 metric tons of aluminium scrap annually, turning it back into high-value aluminium ingots to feed the company’s European manufacturing network.

“The Nachterstedt Recycling Centre is a significant step toward our goal to be the world’s low-carbon aluminium sheet producer, shifting our business model from a traditional linear approach to an increasingly closed-loop model,” said Phil Martens, president and chief executive officer of Novelis.  (3)

References:

(1) http://www.prnewswire.com/news-releases/novelis-reports-significant-gains-in-sustainability-300379847.html

(2) http://novelis.com/about-us/assets-and-capabilities/

(3) http://www.ciwm-journal.co.uk/novelis-opens-worlds-largest-aluminium-recycling-facility/

Related Posts:

Embodied Energy https://duanetilden.com/2014/12/10/embodied-energy-a-measure-of-sustainability-in-buildings-construction/

Energy Efficiency  https://duanetilden.com/2016/06/19/measuring-and-monitoring-energy-efficiency/

 

Mass Transit Prioritized in US Election – $200 Billion Approved by Voters

As gridlock continues to be a problem in the United States, exacerbated by crumbling infrastructure, the American public has reportedly approved up to $200 billion for rapid and mass transit.

According to the American Public Transportation Association (Apta), the 49 ballot measures totalling nearly $US 200bn that were voted on were the largest in history.  […]

The largest measure in the country, Los Angeles County’s Measure M, was passed with 69% approval with all precincts reporting. The sales tax increase needed a two-thirds majority to pass and is expected to raise $US 120bn over 40 years to help fund transport improvement projects, including Los Angeles County Metropolitan Transportation Authority (LACMTA) schemes to connect Los Angeles International Airport to LACMTA’s Green Line, Crenshaw/LAX line and bus services; extend the Purple Line metro to Westwood; extend the Gold Line 11.7km; extend the Crenshaw Line north to West Hollywood; and build a 6.1km downtown light rail line. The measure will also provide $US 29.9bn towards rail and bus operations, and $US 1.9bn for regional rail.

California’s other big transit wins include Measure RR in the San Francisco Bay area, which will authorise $US 3.5bn in bonds for Bay Area Rapid Transit rehabilitation and modernisation. It required a cumulative two-thirds vote in San Francisco, Alameda and Contra Costa counties for passage and received 70% approval. (1)

Image result for BART train

Figure 1.  Bay Area Rapid Transit (2)

 

BART’s Focus on Material Conservation, Energy Savings and Sustainability

BART’s infrastructure requires the train cars to be extremely lightweight. To meet this requirement, most of the exterior of the new train cars will be constructed out of aluminum. Aluminum is abundant, doesn’t rust, and when properly finished, reflects heat and light, keeping the train cars cool. It is lightweight but strong, yet fairly easy to work with, reducing the energy investment during the manufacturing process. Additionally, aluminum is easily and readily recyclable, making it very low impact when the train cars are eventually retired and dismantled.  (2)

Federal Investment in Rapid Transit and Transportation Infrastructure Lagging

Yet, despite the public’s continued desire to see greater investment in transit, historically transit has received only a small minority of funding at the federal level. Currently, only 20 percent of available federal transportation funds are invested in transit and just 1 percent of funds are invested in biking and walking infrastructure. Meanwhile, 80 percent of federal transportation dollars continue to be spent on roads.

“While many localities recognize the need to invest in transit, biking, and pedestrian solutions that can bring our transportation system into the 21st century, federal officials remain woefully behind the curve,” said Olivieri. “While it is great to see such widespread support of transit at the local level, the need for these measures speaks volumes about how out of sync federal decision makers are with the wants and needs of the American people,” he added.

The nation currently faces an $86 billion transit maintenance repair backlog, while data from the Federal Highway Administration’s National Bridge Inventory show that despite the large discrepancy at the federal level between investment in transit and spending on roads, the nation’s road system is in similarly bad shape. To date, more than 58,000 bridges remain structurally deficient.

“Despite the fact that roads receive 80 percent of available federal transportation dollars, both transit and roads continue to face enormous repair and maintenance backlogs,” said Lauren Aragon, Transportation Fellow at U.S. PIRG. “While the overall level of funding is important, how states spend the limited federal funding they receive can have even greater consequences but states continue to funnel road funding into new and wider highway projects, leaving the existing system to crumble. We need to fix what we have already built first,” she added.  (3)

MAY15_11_000001667330

Figure 2. Typical image of steel bridge in disrepair (4)

 

Harvard Business Review Reports on Crumbling American Infrastructure

Bridges are crumbling, buses are past their prime, roads badly need repair, airports look shabby, trains can’t reach high speeds, and traffic congestion plagues every city. How could an advanced country, once the model for the world’s most modern transportation innovations, slip so badly?

The glory years were decades ago. Since then, other countries surpassed the U.S. in ease of getting around, which has implications for businesses and quality of life. For example, Japan just celebrated the 50thanniversary of its famed bullet train network, the Shinkansen. Those trains routinely operate at speeds of 150 to 200 miles per hour, and in 2012, the average deviation from schedule was a miniscule 36 seconds. Fifty years later, the U.S. doesn’t have anything like that. Amtrak’s “high-speed” Acela between Washington, D.C., and Boston can get up to full speed of 150 mph only for a short stretch in Rhode Island and Massachusetts, because it is plagued by curves in tracks laid over a century ago and aging components, such as some electric overhead wiring dating to the early 1900s.

Numerous problems plague businesses and consumers: Goods are delayed at clogged ports. Delayed or cancelled flights cost the U.S. economy an estimated $30-40 billion per year – not to mention ill will of disgruntled passengers. The average American wastes 38 hours a year stuck in traffic. This amounts to 5.5 billion hours in lost U.S. productivity annually, 2.9 gallons of wasted fuel, and a public health cost of pollution of about $15 billion per year, according to Harvard School of Public Health researchers. The average family of four spends as much as 19% of its household budget on transportation. But inequality also kicks in: the poor can’t afford cars, yet are concentrated in places without access to public transportation. To top it all, federal funding for highways, with a portion for mass transit, is about to run out.  (4)

 

References:

(1)  Nearly 70% of US transit ballot measures pass;  http://www.railjournal.com/index.php/north-america/nearly-70-of-us-transit-ballot-measures-pass.html

(2)  BART – New Train Car Project;  http://www.bart.gov/about/projects/cars/sustainability

(3)  BILLIONS IN TRANSIT BALLOT INITIATIVES GET GREEN LIGHT;  http://www.uspirg.org/news/usp/billions-transit-ballot-initiatives-get-green-light

(4)  What It Will Take to Fix America’s Crumbling Infrastructure;  https://hbr.org/2015/05/what-it-will-take-to-fix-americas-crumbling-infrastructure

Aluminum, a Quantum Leap in Renewable Energy Storage

The future for the metal aluminum has never looked better, for the great investment it represents as a multi-faceted energy efficiency lending material, electrical energy storage medium (battery), and for the advancement of renewable energy sources.  These are spectacular claims, and yet in 1855 aluminum was so scarce it sold for about 1200 $/Kg (1) until metallurgists Hall & Heroult invented the modern smelting process over 100 years ago (2).

Image result for aluminum electrolysis

Figure 1.  Schematic of Hall Heroult Aluminum Reduction Cell (3)

 

Aluminum is an energy intensive production process.  High temperatures are required to melt aluminum to the molten state.  Carbon electrodes are used to melt an alchemical mixture of alumina with molten cryolite, a naturally occurring mineral.  The cryolite acts as an electrolyte to the carbon anode and cathodes.  Alumina (Al2O3) also known as aluminum oxide or Bauxite is fed into the cell and dissolved into the cryolite, over-voltages reduce the Al2O3 into molten aluminum which pools at the bottom of the cell and is tapped out for further refining.

Aluminum Smelting Process as a Battery

The smelting of Aluminum is a reversible electrolytic reaction, and with modifications to current plant design it is possible to convert the process to provide energy storage which can  be tapped and supplied to the electrical grid when required.  According to the research the biggest challenge to this conversion process is to maintain heat balances of the pots when discharging energy to prevent freeze-up of the cells.  Trimet Aluminum has overcome this problem by incorporating shell heat-exchange technology to the sides of the cell to maintain operating temperatures.  Trial runs with this technology have been positive where plans are to push the technology to +/- 25% energy input/output.  If this technology is applied to all 3 Trimet plants in Germany, it is claimed that up to 7700 MWh of electrical storage is possible (4).

Trimet Aluminum SE, Germany’s largest producer of the metal, is experimenting with using vast pools of molten aluminum as virtual batteries. The company is turning aluminum oxide into aluminum by way of electrolysis in a chemical process that uses an electric current to separate the aluminum from oxygen. The negative and positive electrodes, in combination with the liquid metal that settles at the bottom of the tank and the oxygen above, form an enormous battery.

By controlling the rate of electrolysis, Trimet has been able to experiment with both electricity consumption and storage.  By slowing down the electrolysis process, the plant is able to adjust its energy consumption up and down by roughly 25 percent.  This allows the plant to store power from the grid when energy is cheap and abundant and resell power when demand is high and supply is scarce. (5)

Related image

Figure 2. TRIMET Aluminium SE Hamburg with emission control technology (6)

 

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Figure 3.  Rio Tinto Alcan inaugurates new AP60 aluminum smelter in Quebec (7)

Aluminum as a Material and it’s Energy Efficiency Properties

Aluminum and it’s alloys generally have high strength-to-weight ratio’s and are often specified in the aircraft industry where weight reduction is critical.  A plane made of steel would require more energy to fly,  as the metal is heavier for a given strength.  For marine vessels, an aluminum hull structure, built to the same standards, weighs roughly 35% to 45% less than the same hull in steel (8). Weight reduction directly converts to energy savings as more energy would be required to propel the aircraft.

Other modes of transportation, including automobiles, trucking, and rail transport may similarly also benefit from being constructed of lighter materials, such as aluminum.  Indeed this would continue the long-standing trend of weight reduction in the design of vehicles.  The recent emergence of electric vehicles (EV’s) have required weight reduction to offset the high weight of batteries which are necessary for their operations.  The weight reduction translates into longer range and better handling.

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Figure 4.  Tesla Model S (9)

 

In the 1960s, aluminium was used in the niche market for cog railways. Then, in the 1980s, aluminium emerged as the metal of choice for suburban transportation and high-speed trains, which benefited from lower running costs and improved acceleration. In 1996, the TGV Duplex train was introduced, combining the concept of high speed with that of optimal capacity, transporting 40% more passengers while weighing 12% less than the single deck version, all thanks to its aluminium structure.

Today, aluminium metros and trams operate in many countries. Canada’s LRC, France’s TGV Duplex trains and Japan’s Hikari Rail Star, the newest version of the Shinkansen Bullet train, all utilize large amounts of aluminium.  (10)

Image result

Figure 5.   Image of Japanese Bullet Train  (11)

Aluminum For Renewable Energy

One of the biggest criticisms against renewable technologies, such as solar and wind has been that they are intermittent, and not always available when demand demand for energy is high.  Even in traditional grid type fossil fuel plants it has been necessary to operate “peaker plants” which provide energy during peak times and seasons.

In California, recent technological breakthroughs in battery technology have been seen as a means of providing storage options to replace power plants for peak operation. However, there remains skepticism that battery solutions will be able to provide the necessary storage capacity needed during these times (12).  The aluminum smelter as an energy provider during these high demand times may be the optimum solution needed in a new age renewables economy.

The EnPot technology has the potential to make the aluminium smelting industry not only more competitive, but also more responsive to the wider community and environment around it, especially as nations try to increase the percentage of power generated from renewable sources.

The flexibility EnPot offers smelter operators can allow the aluminium industry to be part of the solution of accommodating increased intermittency.  (13)

References:

(1)  http://www.aluminum-production.com/aluminum_history.html

(2)  http://www.aluminum-production.com/Basic_functioning.html

(3)  http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532000000300008

(4)  The ‘Virtual Battery‘ – Operating an Aluminium Smelter with Flexible Energy Input.  https://energiapotior.squarespace.com/s/Enpot-Trimet-LightMetals2016.pdf

(5)  http://www.metalsproclimate.com/metals-pro-climate/best-practice/reduction-of-pfc-process-emissions

(6) http://www.sauder.ubc.ca/Faculty/Research_Centres/Centre_for_Social_Innovation_and_Impact_Investing/Programs/Clean_Capital/Clean_Capital_News_Archive_2014/Aluminum_smelters_could_act_as_enormous_batteries

(7)  http://www.canadianmetalworking.com/2014/01/rio-tinto-alcan-inaugurates-new-ap60-aluminum-smelter-in-quebec/

(8)  http://www.kastenmarine.com/alumVSsteel.htm

(9)  http://www.greencarreports.com/news/1077672_2012-tesla-model-s-is-aluminum-its-secret-weapon

(10)  http://transport.world-aluminium.org/en/modes/trainssubways.html

(11)  http://www.aluminiumleader.com/focus/aluminium_carriages_help_provide_high_speed_rail_service/

(12)  http://www.bloomberg.com/news/articles/2015-12-22/batteries-gaining-favor-over-gas-peaker-plants-in-california

(13)  http://www.energiapotior.com/the-virtual-battery

Company Developing Thermo-Electric Materials for Waste-Heat Energy Recovery

NASA’s Jet Propulsion Laboratory, Pasadena, California, has licensed patents on high-temperature thermoelectric materials to Evident Technologies, Troy, New York, which provides these kinds of materials and related power systems.

Source: phys.org

>” […] Thermoelectric materials convert heat into electricity. For example, by using this technology, waste-heat from a car could potentially be fed back into the vehicle and used to generate electricity. This would increase efficiency and deliver low-cost solutions for harvesting waste heat.

“The licensed technology could be applied to convert heat into electricity in a number of waste heat recovery applications, including automobile exhaust and high-temperature industrial processes such as ceramic and glass processing plants,” said Thierry Caillat, task leader for the thermoelectrics team at JPL.

JPL has a long history of high-temperature thermoelectric development driven by the need for space mission power in the absence of sunlight. Many space probes that leave Earth’s orbit use thermoelectrics as their electrical power source.  […]”<

See on Scoop.itGreen Energy Technologies & Development

Aluminum Superatoms – High Temperature Superconducting Materials

Superconductors can carry electricity with no resistance and are used for specialized applications like MRIs, maglev trains and particle accelerators. Superconductor-based electronics would be extremely efficient because they would generate no waste heat, but he fact that they would only work at temperatures close to absolute zero makes them impractical.

Source: www.gizmag.com

>” […]

Scientists at the University of Southern California (USC) have made steps toward discovering a new family of superconductor materials that work at relatively high temperatures, with possible applications in physics research, medical imaging and high-performance electronics.

As electrons travel through an integrated circuit, they regularly bump into microscopic imperfections within the conductive wire and veer off course, creating electrical resistance and releasing waste energy as heat. Waste heat is a big inconvenience to both designers and end-users of electronics, but it simply can’t be avoided using the materials currently at our disposal.

[…] Thirty years ago, a new class of so-called “high-temperature superconductors” was discovered, although the name can be deceiving because these still require temperatures below 135 K (-135 °C or -210 °F) to operate, which still makes them impractical for use in electronics.

Now the USC team led by professor Vitaly Kresin has discovered hints of yet another family of superconductors which work at relatively high temperatures. Specifically, they found out that while single atoms of aluminum only turn superconductive at very low temperatures (around 1 K), so-called “superatoms” (clusters of evenly spaced atoms that behave as a single atom) of aluminum turn superconductive at much higher temperatures, around 100 K.

Superconductivity takes place when so-called Cooper pairs form within a material. These are pairs of electrons that are very faintly attracted to each other and activate a mechanism whereby the electrons don’t veer off course, and therefore lose heat, whenever they bump into an imperfection within the material. Because the attractive force between the electrons, which happens only under certain conditions, is so weak (two electrons would normally repel each other), even a small amount of external energy (which could be given off in the form of heat) can upset this equilibrium. This is why superconductors only work at very low temperatures.

Kresin and team built a series of aluminum superatoms between 32 and 95 atoms large. For superatoms containing 37, 44, 66 and 68 aluminum atoms, the scientists found evidence that Cooper pairings were taking place, turning the material into a superconductor.

The researchers suggest that creating superatoms of different metals could lead to the discovery of similar superconductors that work at relatively high temperatures. While the threshold temperature was 100 K (-280 °F, -173 °C) for an aluminum superatom, different materials are likely to turn superconductive at different (hopefully much higher) temperatures.

“One-hundred Kelvin might not be the upper-temperature barrier,” says Kresin. “It might just be the beginning.”

Should one of these materials operate as a superconductor at room temperature, it would likely have huge impact on the worlds of electronics, medical imaging, microscopy and electric motors, just to name a few. ”

A paper describing the advance appears on the journal Nano Letters.

Source: University of Southern California

See on Scoop.itGreen Energy Technologies & Development

Wide Bandgap Semiconductors – LED’s and the Future of Power Electronics

Hidden inside nearly every modern electronic is a technology — called power electronics — that is quietly making our wor…

Source: www.youtube.com

See on Scoop.itGreen Energy Technologies & Development

 

“Hidden inside nearly every modern electronic is a technology — called power electronics — that is quietly making our world run. Yet, as things like our phones, appliances and cars advance, current power electronics will no longer be able to meet our needs, making it essential that we invest in the future of this technology.

Today [January 15, 2014], President Obama will announce that North Carolina State University will lead the Energy Department’s new manufacturing innovation institute for the next generation of power electronics. The institute will work to drive down the costs of and build America’s manufacturing leadership in wide bandgap (WBG) semiconductor-based power electronics — leading to more affordable products for businesses and consumers, billions of dollars in energy savings and high-quality U.S. manufacturing jobs.

Integral to consumer electronics and many clean energy technologies, power electronics can be found in everything from electric vehicles and industrial motors, to laptop power adaptors and inverters that connect solar panels and wind turbines to the electric grid. For nearly 50 years, silicon chips have been the basis of power electronics. However, as clean energy technologies and the electronics industry has advanced, silicon chips are reaching their limits in power conversion — resulting in wasted heat and higher energy consumption.

Power electronics that use WBG semiconductors have the potential to change all this. WBG semiconductors operate at high temperatures, frequencies and voltages — all helping to eliminate up to 90 percent of the power losses in electricity conversion compared to current technology. This in turn means that power electronics can be smaller because they need fewer semiconductor chips, and the technologies that rely on power electronics — like electric vehicle chargers, consumer appliances and LEDs — will perform better, be more efficient and cost less.

One of three new institutes in the President’s National Network of Manufacturing Innovation, the Energy Department’s institute will develop the infrastructure needed to make WBG semiconductor-based power electronics cost competitive with silicon chips in the next five years. Working with more than 25 partners across industry, academia, and state and federal organizations, the institute will provide shared research and development, manufacturing equipment, and product testing to create new semiconductor technology that is up to 10 times more powerful that current chips on the market. Through higher education programs and internships, the institute will ensure that the U.S. has the workforce necessary to be the leader in the next generation of power electronics manufacturing.

Watch our latest video on how wide bandgap semiconductors could impact clean energy technology and our daily lives.”

source:  http://energy.gov/articles/wide-bandgap-semiconductors-essential-our-technology-future

 

Thermoelectric Solid-State Cooling Technology Wins $44.5M Funding

The near-term applications for Phononic’s science are high-end refrigeration for labs and medical facilities, as well as cooling for fiber optics and data servers that are “necessary to continue Moore’s law,” according to the company.

Source: www.greentechmedia.com

>” […] The 75-employee Phononic develops thermoelectrics — materials that can convert a temperature gradient to a voltage or vice versa. The technology is a brilliant pursuit, but no one has brought it to mass markets economically or at scale just yet. Traditional thermoelectrics use materials such as bismuth telluride or silicon germanium, and more recently, silicon nanowires.

[…] Phononic is looking to develop thermal management technology for consumer devices, and, more strikingly, to replace cheap, ubiquitous and century-old incumbent compressor technology.

CEO Anthony Atti told us this morning that the investment thesis around Phononic is that “semiconductors have revolutionized IT and LEDs, but have not had that same impact on cooling and heating.” He notes that Phononic’s thermoelectric technology is in the realm of Peltier cooling technology, but addresses three major shortcomings of that technology: efficiency, ability to scale, and ease of integration. […]

Atti claims that the compound semiconductor material used in his firm’s thermoelectrics can be manufactured using high-volume, standard semiconductor tools and equipment.

Bruce Sohn, the former president of First Solar, is on the board at Phononic. When we spoke with him this morning, he told us that he had been working with the firm for four years and believes the startup is doing something “revolutionary that can do to compressors what the [integrated circuit] did to the vacuum tube.”

Other companies developing thermoelectric technologies for cooling or capturing waste heat include the following:

  • Alphabet Energy is commercializing thermoelectric waste-heat harvesting technology developed at Lawrence Berkeley National Laboratory and has raised more than $30 million from Encana, a developer of natural gas and other energy sources,
  • TPG Biotech, Claremont Creek Ventures, and the CalCEF Clean Energy Angel Fund.GMZ Energy, spun out of MIT with funding from KPCB, BP Alternative Energy, and Mitsui Ventures, is working on a bismuth-telluride thermovoltaic device that converts solar heat directly into power via the Seebeck effect. In the Seebeck effect, a sharp temperature gradient can result in an electric charge.
  • MTPV describes its product as a thermophotovoltaic. MTPV uses a silicon-based MEMS emitter which takes heat and transfers radiation to a germanium-based photovoltaic device, according to an article inSemiconductor Manufacturing and Design. The company just raised $11.2 million led by Northwater Capital Management’s Intellectual Property Fund, along with Total Energy Ventures, SABIC, the Saudi Basic Industries Corporation, and follow-on investments from Spinnaker Capital, Ensys Capital, the Clean Energy Venture Group and other existing shareholders.
  • Silicium, funded by Khosla Ventures, is investigating high ZT thermoelectrics. The firm’s website claims, “Silicium is developing silicon thermoelectrics that enable substantially increased battery longevity for wearable electronics. By using body heat, Silicium technology can help power an entire spectrum of wearable devices…using off-the-shelf silicon wafers.
  • “Recycled Energy Development (RED) and Ormat have retrofitted factories to capture waste heat, not using thermoelectrics, but by adding CHP or cogeneration. […]”<

See on Scoop.itGreen Energy Technologies & Development

Embodied Energy – A Measure of Sustainability in Buildings & Construction

Embodied energy in building materials has been studied for the past several decades by researchers interested in the relationship between building materials, construction processes, and their environmental impacts.

Source: www.canadianarchitect.com

>” […]

What is embodied energy?
There are two forms of embodied energy in buildings:

· Initial embodied energy; and
· Recurring embodied energy

1.  The initial embodied energy in buildings represents the non-renewable energy consumed in the acquisition of raw materials, their processing, manufacturing, transportation to site, and construction. This initial embodied energy has two components:

  • Direct energy the energy used to transport building products to the site, and then to construct the building; and
  • Indirect energy the energy used to acquire, process, and manufacture the building materials, including any transportation related to these activities.

2.  The recurring embodied energy in buildings represents the non-renewable energy consumed to maintain, repair, restore, refurbish or replace materials, components or systems during the life of the building.

As buildings become more energy-efficient, the ratio of embodied energy to lifetime consumption increases. Clearly, for buildings claiming to be “zero-energy” or “autonomous”, the energy used in construction and final disposal takes on a new significance. […]”<

See on Scoop.itGreen & Sustainable News

Scientists Discover New Form of Crystalline Order with High Potential for Thermoelectrics

 

InterlacedCrystalsSince the 1850s scientists have known that crystalline materials are organized into 14 different basic lattice structures. However, a team of researchers from Vanderbilt University and Oak Ridge National Laboratory (ORNL) now reports that it has discovered an entirely new form of crystalline order that simultaneously exhibits both crystal and polycrystalline properties, which they describe as “interlaced crystals.”

Source: www.energyharvestingjournal.com

>” […] The interlaced crystal arrangement has properties that make it ideal for thermoelectric applications that turn heat into electricity, they report. The discovery of materials with improved thermoelectric efficiency could increase the efficiency of electrical power generation, improve automobile mileage and reduce the cost of air conditioning.   “We discovered this new form while studying nano particles,” said Sokrates Pantelides, University Distinguished Professor of Physics and Engineering at Vanderbilt, who coordinated the study. “It most likely exists in thin films or bulk samples, but it has apparently gone unnoticed.”  […]

According to the researchers, the interlaced crystal structure may be just what is needed to optimize thermoelectric applications for power generation or cooling. Thermoelectric devices need a material that is an excellent electrical conductor and a poor conductor of heat. The problem is that materials like metals that are good electrical conductors also tend to be good heat conductors and vice versa. Defects and grain boundaries that retard heat flow also reduce electrical conductivity.   In addition to CuInS2, there is a large class of materials that should have similar interlaced structures. When made into thin films, they should be excellent thermoelectric materials, the researchers predict.   “We haven’t tested this yet, but we are confident that these materials have high electrical conductivity and low thermal conductivity…just what you need for thermoelectrics. The field is now wide open for scientists who can fabricate thin films and make thermoelectric measurements,” said Pantelides.”<

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Call for Energy Efficient Air-Conditioning with Technological Development

See on Scoop.itGreen Building Design – Architecture & Engineering

Innovations could cut the growing amount of energy used for air-conditioning and refrigeration

Duane Tilden‘s insight:

>Conventional air conditioners employ refrigerants such as chlorofluorocarbons to absorb heat from the room to be cooled. That heat is then expelled outside, requiring electrically powered pumps and compressors.

One idea to conserve energy is to replace coolant fluids and gases—which are often super-powered greenhouse gases capable of trapping more than 1,000 times more heat than CO2—with solid materials, such as bismuth telluride.

A new device from Sheetak, developed in part with ARPA-E funding, uses electricity to change a thermoelectric solid to absorb heat, and could lead to cheaper air conditioners or refrigerators.

Such refrigerators, which lack moving parts and are therefore less likely to break down, can be lifesavers in remote, rural areas for keeping medicines cool or food fresh.<

See on www.scientificamerican.com