Soon we may be able to power our iPads, iPhones and other portable electronics with just the tap of our finger.


That’s because researchers at RMIT University in Melbourne have for the first time discovered how they can use piezoelectric thin films to turn mechanical pressure into electricity.

Lead co-author of the findings at RMIT, Dr Madhu Bhaskaran, said the university’s research combined the potential of piezoelectrics – materials capable of converting pressure into electrical energy – and the cornerstone of microchip manufacturing, thin film technology.

Dr Madhu Bhaskaran.Dr Madhu Bhaskaran.

“The power of piezoelectrics could be integrated into running shoes to charge mobile phones, enable laptops to be powered through typing or even used to convert blood pressure into a power source for pacemakers – essentially creating an everlasting battery,” Dr Bhaskaran said.

The Australian Research Council-funded study assessed the energy generation capabilities of piezoelectric thin films at the nanoscale, for the first time precisely measuring the level of electrical voltage and current – and therefore, power – that could be generated.

“The next key challenge will be amplifying the electrical energy generated by the piezoelectric materials to enable them to be integrated into low-cost, compact structures,” Dr Bhaskaran said.

A club in London has used piezoelectricity to generate about 60 per cent of the energy needed to run the club. It requires people to dance on its dance floor to generate electricity.

Solve the world’s energy problems?

Piezoelectric thin films were “never going to be something that’s going to save the energy problems of the world”, Dr Bhaskaran told Fairfax Media, publisher of this website.

This was because the amount of electricity generated from the pressure would not be enough to power anything other than something that “runs off a couple of batteries”, Dr Bhaskaran said.

In about five or six years we would begin to see the first devices integrating piezoelectrics, she said.

Dr Bhaskaran co-authored the study with Dr Sharath Sriram, within RMIT’s Microplatforms Research Group, which is led by Professor Arnan Mitchell. The pair collaborated with Australian National University’s Dr Simon Ruffell on the research.

The study was published in materials science journal Advanced Functional Materials.

Sourced & published by Henry Sapiecha

Huge X-class solar flare

could jam satellite signals

February 18, 2011

A powerful solar eruption that has already disturbed radio communications in China could disrupt electrical power grids and satellites used on Earth in the next days, NASA said.

The massive sunspot, which astronomers say is the size of Jupiter, is the strongest solar flare in four years, NASA said.

The Class X flash – the largest such category – erupted at 12.56pm [AEDT] on Tuesday, according to the US space agency.

A powerfuil solar eruption could disrupt satellites on Earth.A powerful solar eruption could disrupt satellites on Earth. Photo: AFP

“X-class flares are the most powerful of all solar events that can trigger radio blackouts and long-lasting radiation storms, disturbing telecommunications and electric grids,” NASA said.

NASA’s Solar Dynamics Observatory saw a large coronal mass ejection (CME) associated with the flash that is blasting towards Earth about 900 kilometres per second, it said.

The charged plasma particles were expected to reach the planet’s orbit at 2.00pm [AEDT] yesterday.

The flare spread from Active Region 1158 in the sun’s southern hemisphere, which had so far lagged behind the northern hemisphere in flash activity. It followed several smaller flares in recent days.

“The calm before the storm,” read a statement on the US National Weather Service Space Weather Prediction Service.

“Three CMEs are enroute, all a part of the Radio Blackout events on February 13, 14, and 15 [UTC]. The last of the three seems to be the fastest and may catch both of the forerunners about mid to late … February 17.”

Geomagnetic storms usually last 24 to 48 hours, “but some may last for many days”, read a separate NWS statement.

“Ground-to-air, ship-to-shore, shortwave broadcast and amateur radio are vulnerable to disruption during geomagnetic storms. Navigation systems like GPS can also be adversely affected.”

The China Meteorological Administration reported that the solar flare had jammed shortwave radio communications in southern China.

It said the flare caused “sudden ionospheric disturbances” in the atmosphere above China, and warned there was a high probability that large solar flares would appear over the next three days, the official Xinhua news agency reported.

In previous major disturbance of the Earth’s electric grid from a solar incident, in 1973, a magnetic storm caused by a solar eruption plunged six million people into darkness in Canada’s eastern-central Quebec province.

The British Geological Survey [BGS] said meanwhile that the solar storm would result in spectacular Northern Lights displays starting on Thursday.

One coronal mass ejection [CME] arrived on February 14, “sparking Valentine’s Day displays of the Northern Lights [aurora borealis] further south than usual”.

“Two CMEs are expected to arrive in the next 24-48 hours and further … displays are possible some time over the next two nights if skies are clear,” it said.

The office published geomagnetic records dating back to the Victorian era which it hopes will help in planning for future storms.

“Life increasingly depends on technologies that didn’t exist when the magnetic recordings began,” said Alan Thomson, BGS head of geomagnetism.

“Studying the records will tell us what we have to plan and prepare for to make sure systems can resist solar storms,” he said.

AFP Sourced & published by Henry Sapiecha


PowerTrekk fuel cell charger

allows for power on the go

By Paul Ridden

07:45 February 14, 2011

SiGNa Chemistry and myFC have developed the PowerTrekk, a 2-in-1 portable charging solutio...

SiGNa Chemistry and myFC have developed the PowerTrekk, a 2-in-1 portable charging solution that consists of a Li-ion battery pack and a hydrogen fuel cell

Outdoor types who need power for mobile devices away from the grid may find themselves carrying solar chargers or battery packs but, as we reported last year, hydrogen fuel cells offer instant juice benefits and zero degradation. Now, Stockholm’s myFC and SiGNa Chemistry have teamed up to launch the PowerTrekk, a pocket-sized, portable charging solution that combines the convenience of a battery pack with the instant power of a hydrogen fuel cell.

  • The PowerTrekk 2-in-1 portable charger is the first to use Mobile-H2 technology from SiGNa...
  • Devices are charged via USB, and the PowerTrekk keeps users informed of what's going on vi...
  • About a tablespoon of water is added to the central well of the PowerPukk after it's place...
  • The PowerTrekk will come in green, red and yellow and is expected to be shipped internatio...

Developed to provide some off-the-grid juice to outdoor enthusiasts or anyone who finds themselves away from a wall socket when their smartphone, GPS or digital camera battery dies, myFC‘s PowerTrekk 2-in-1 portable charger is the first to use Mobile-H2 technology from SiGNa Chemistry. In addition to sporting a Li-ion battery pack, the device also takes a Mobile-H2 cartridge called a PowerPukk.

The PowerPukk disc contains sodium silicide (NaSi), a non-flammable powder which rapidly produces hydrogen thanks to a stable and controllable reaction with a wide variety of non-potable, non-distilled water – including salt water – at room temperature. SiGNa says that the powder is generated from salt (sodium chloride) and sand (silicon dioxide) starting materials in a solvent- and purification-free process where the heat generated during manufacture is recaptured and used within the process, keeping energy consumption down.

About a tablespoon of water is added to the central well of the PowerPukk after it’s placed inside the belly of the PowerTrekk, after which the device’s Proton Exchange Membrane starts to silently convert the hydrogen into electricity. The only by-product of the process is a little water vapor. There’s no more waiting around for the sun to harvest enough energy to power your gadgets, and the unit is said not to suffer from degradation often associated with battery packs.

The PowerTrekk’s built-in Li-ion battery buffer has a capacity of 5.9 Wh (1600 mAh, 3.7 V) and the device has a rated output of 5V, 1000 mA and rated input of 5V, 500 mA. The PowerPukk Fuel Cartridge can be swapped out without interrupting the supply of power to the attached mobile device.

PowerPukk cartridges come in either five or ten packs and have a shelf life of two years minimum. myFC says that the fuel cell “is part of an industry program for reusing its materials and is made of coated can materials which prevent corrosion and leakage of chemicals,” and the PowerTrekk itself should become part of the industry’s electronic waste recycling program at the end of its operational life.

The 2.59 x 5 x 1.65-inch (66 x 128 x 42mm) PowerTrekk, which is currently on display at Mobile World Congress 2011 in Barcelona, will come in green, red or yellow and is expected to be shipped internationally in October for about US$200.

Sourced & published by Henry Sapiecha

Cars of Tomorrow

Automotive Engineers Team Up to

Improve Energy-Saving Technology

DAIMLER CHRYSLER HYBRID CAR

October 1, 2006 — Mechanical and electrical engineers at DaimlerChrysler, General Motors and BMW have jointly developed a hybrid-vehicle technology that shuts the internal combustion engine off when the vehicle stops. Meanwhile, engineers are working to replace the platinum in fuel cells with cheaper materials, which could lead to viable hydrogen cars.


AUBURN HILLS, Mich. — The high cost of hybrids has kept many people from going green, and a new Edmonds.com study shows that with the cost of gas — combined with tax credits — it only takes about three years to break even.

Now a new breed of hybrid is going to lessen that time even more. It’s the brainchild of not one car company but DaimlerChrysler, General Motors and BMW! They are all working together to create the car of tomorrow.

As gas prices go up, the pressure is on to create cars that use less.

“The hybrid system that we’re developing, we can apply to any vehicle that we have,” Glenn Denomme, a chief engineer of Hybrid Powertrain Programs at DaimlerChrysler in Auburn Hills, Michigan, tells DBIS.

It allows for increased performance compared to a conventional SUV and improves fuel economy by up to 25 percent. Denomme says, “You can still haul your cargo, but you can still be environmentally sound too.”

Today’s hybrid works best in stop-and-go traffic — tomorrow’s hybrid will give you better fuel economy, not only in the city, but on the highway. When the new hybrid is stopped, the advanced system shuts the internal combustion engine off, conserving fuel. When the car starts to move, electric power is used to conserve fuel, adding power from the engine as needed.

Speeding up even more, power from both the engine and electric motors are routed to the wheels for greater acceleration.

The new technology doesn’t stop there! A fuel cell car is 100-percent electric.

“It takes hydrogen and oxygen, combines it to form water, and at the same time produces electricity,” says Doanh Tran, an advanced vehicle engineer with DaimlerChrysler’s Fuel Cell Vehicles & Technologies.

Hydrogen can be produced from just about anything that has a hydrogen molecule, and the car has no emission out of the tailpipe except water vapor.

Right now, platinum is used for the fuel cell’s parts and is expensive, but materials engineers are working to find new metals. And as for mileage, it gets 56 miles per gallon, so a little can go a long way.

The fuel cell car won’t be for sale until around 2012. The new DaimlerChrysler hybrid will hit the market in 2008. It will cost more than a conventional car, but the price hasn’t been set yet.

BACKGROUND: The German-American consortium of BMW, DaimlerChrysler and General Motors are developing a new type of two-mode hybrid system for a wide range of cars, trucks and SUVs, starting with the 2008 Chevrolet Tahoe available in fall 2007. Current hybrids perform well in stop-and-go city driving, but don’t get as good mileage on the highway. The new hybrid version will get 25 percent better mileage in combined city and highway driving.

ADVANTAGES: Current hybrid engine systems have a single mode of operation, using a single gear set to split the engine’s power into two systems — routing it to drive the wheels or charge the battery — for both city and highway driving. Like other hybrids, the two-mode combines the power of a gasoline engine with that of electric motors, capturing energy from braking that would otherwise be lost and shutting off the engine at a stop. The battery alone can power the vehicle at low speeds. The new technology can operate much more efficiently at highway speeds with a greater boost from the electric motors, shutting down half the cylinders when not needed, thereby improving gas mileage. The components of the new two-mode system are also lighter and more compact, making them especially useful for reducing overall fuel consumption.

BATTERY BASICS: Whenever one type of matter converts into another, as in a chemical reaction, one form of energy also changes into another. A battery has two ends, called terminals, one with a negative charge, and one with a positive charge. Electrons congregate on the negative terminal. Connect a wire between the two terminals, and the electrons will flow from the negative to the positive end as quickly as they can. Connecting the battery starts the flow of electrons, jumpstarting a series of chemical reactions inside the battery to create even more electrons.

HOW FUEL CELLS WORK: Just like batteries, a fuel cell is a device that uses chemical reactions to convert hydrogen and oxygen into water, producing electricity in the process. A battery eventually goes dead when all the chemicals are used up, but in a fuel cell, there is a constant flow of chemicals into the cell. The voltage produced by fuel cells can be used to power lights, electrical appliances, and laptops, as well as cars and trucks. Fuel cells are light, more efficient than internal combustion engines, and don’t produce damaging emissions. They are currently expensive to manufacture, however.

Sourced and published by Henry Sapiecha 14th April 2010

Viruses Harnessed to Split Water

ScienceDaily (Apr. 12, 2010) — A team of MIT researchers has found a novel way to mimic the process by which plants use the power of sunlight to split water and make chemical fuel to power their growth. In this case, the team used a modified virus as a kind of biological scaffold that can assemble the nanoscale components needed to split a water molecule into hydrogen and oxygen atoms.


Splitting water is one way to solve the basic problem of solar energy: It’s only available when the sun shines. By using sunlight to make hydrogen from water, the hydrogen can then be stored and used at any time to generate electricity using a fuel cell, or to make liquid fuels (or be used directly) for cars and trucks.

Other researchers have made systems that use electricity, which can be provided by solar panels, to split water molecules, but the new biologically based system skips the intermediate steps and uses sunlight to power the reaction directly. The advance is described in a paper published on April 11 in Nature Nanotechnology.

The team, led by Angela Belcher, the Germeshausen Professor of Materials Science and Engineering and Biological Engineering, engineered a common, harmless bacterial virus called M13 so that it would attract and bind with molecules of a catalyst (the team used iridium oxide) and a biological pigment (zinc porphyrins). The viruses became wire-like devices that could very efficiently split the oxygen from water molecules.

Over time, however, the virus-wires would clump together and lose their effectiveness, so the researchers added an extra step: encapsulating them in a microgel matrix, so they maintained their uniform arrangement and kept their stability and efficiency.

While hydrogen obtained from water is the gas that would be used as a fuel, the splitting of oxygen from water is the more technically challenging “half-reaction” in the process, Belcher explains, so her team focused on this part. Plants and cyanobacteria (also called blue-green algae), she says, “have evolved highly organized photosynthetic systems for the efficient oxidation of water.” Other researchers have tried to use the photosynthetic parts of plants directly for harnessing sunlight, but these materials can have structural stability issues.

Belcher decided that instead of borrowing plants’ components, she would borrow their methods. In plant cells, natural pigments are used to absorb sunlight, while catalysts then promote the water-splitting reaction. That’s the process Belcher and her team, including doctoral student Yoon Sung Nam, the lead author of the new paper, decided to imitate.

In the team’s system, the viruses simply act as a kind of scaffolding, causing the pigments and catalysts to line up with the right kind of spacing to trigger the water-splitting reaction. The role of the pigments is “to act as an antenna to capture the light,” Belcher explains, “and then transfer the energy down the length of the virus, like a wire. The virus is a very efficient harvester of light, with these porphyrins attached.

“We use components people have used before,” she adds, “but we use biology to organize them for us, so you get better efficiency.”

Using the virus to make the system assemble itself improves the efficiency of the oxygen production fourfold, Nam says. The researchers hope to find a similar biologically based system to perform the other half of the process, the production of hydrogen. Currently, the hydrogen atoms from the water get split into their component protons and electrons; a second part of the system, now being developed, would combine these back into hydrogen atoms and molecules. The team is also working to find a more commonplace, less-expensive material for the catalyst, to replace the relatively rare and costly iridium used in this proof-of-concept study.

Thomas Mallouk, the DuPont Professor of Materials Chemistry and Physics at Pennsylvania State University, who was not involved in this work, says, “This is an extremely clever piece of work that addresses one of the most difficult problems in artificial photosynthesis, namely, the nanoscale organization of the components in order to control electron transfer rates.”

He adds: “There is a daunting combination of problems to be solved before this or any other artificial photosynthetic system could actually be useful for energy conversion.” To be cost-competitive with other approaches to solar power, he says, the system would need to be at least 10 times more efficient than natural photosynthesis, be able to repeat the reaction a billion times, and use less expensive materials. “This is unlikely to happen in the near future,” he says. “Nevertheless, the design idea illustrated in this paper could ultimately help with an important piece of the puzzle.”

Belcher will not even speculate about how long it might take to develop this into a commercial product, but she says that within two years she expects to have a prototype device that can carry out the whole process of splitting water into oxygen and hydrogen, using a self-sustaining and durable system.

Funding was provided by he Italian energy company Eni, through the MIT Energy Initiative (MITEI)

Sourced and published by Henry Sapiecha 14th April 2010

Blueprint for ‘Artificial Leaf’

Mimics Mother Nature and helps to

turn water to hydrogen for fuel

ScienceDaily (Mar. 26, 2010) — Scientists have presented a design strategy to produce the long-sought artificial leaf, which could harness Mother Nature’s ability to produce energy from sunlight and water in the process called photosynthesis. The new recipe, based on the chemistry and biology of natural leaves, could lead to working prototypes of an artificial leaf that capture solar energy and use it efficiently to change water into hydrogen fuel, they stated.


Their report was scheduled for the 239th National Meeting of the American Chemical Society (ACS) in San Francisco. It was among more than 12,000 scientific reports scheduled for presentation at the meeting, one of the largest scientific gatherings of 2010.

“This concept may provide a new vista for the design of artificial photosynthetic systems based on biological paradigms and build a working prototype to exploit sustainable energy resources,” Tongxiang Fan, Ph.D. and colleagues Di Zhang, Ph.D. and Han Zhou, Ph.D., reported, They are with the State Key Lab of Matrix Composites at Shanghai Jiaotong University, Shanghai, China.

Fan pointed out that using sunlight to split water into its components, hydrogen and oxygen, is one of the most promising and sustainable tactics to escape current dependence on coal, oil, and other traditional fuels. When burned, those fuels release carbon dioxide, the main greenhouse gas. Combustion of hydrogen, in contrast, forms just water vapor. That appeal is central to the much-discussed “Hydrogen Economy,” and some auto companies, such as Toyota, have developed hydrogen-fueled cars. Lacking, however, is a cost-effective sustainable way to produce hydrogen.

With that in mind, Fan and co-workers decided to take a closer look at the leaf, nature’s photosynthetic system, with plans to use its structure as a blueprint for their next generation of artificial systems. Not too surprisingly, the structure of green leaves provides them an extremely high light-harvesting efficiency. Within their architecture are structures responsible focusing and guiding of solar energy into the light-harvesting sections of the leaf, and other functions.

The scientists decided to mimic that natural design in the development of a blueprint for artificial leaf-like structures. It led them to report their recipe for the “Artificial Inorganic Leaf” (AIL), based on the natural leaf and titanium dioxide (TiO2) — a chemical already recognized as a photocatalyst for hydrogen production.

The scientists first infiltrated the leaves of Anemone vitifolia — a plant native to China — with titanium dioxide in a two-step process. Using advanced spectroscopic techniques, the scientists were then able to confirm that the structural features in the leaf favorable for light harvesting were replicated in the new TiO2 structure. Excitingly, the AIL are eight times more active for hydrogen production than TiO2 that has not been “biotemplated” in that fashion. AILs also are more than three times as active as commercial photo-catalysts. Next, the scientists embedded nanoparticles of platinum into the leaf surface. Platinum, along with the nitrogen found naturally in the leaf, helps increase the activity of the artificial leaves by an additional factor of ten.

In his ACS presentation, Fan reported on various aspects of Artificial Inorganic Leaf production, their spectroscopic work to better understand the macro- and microstructure of the photocatalysts, and their comparison to previously reported systems. The activity of these new “leaves,” are significantly higher than those prepared with classic routes. Fan attributes these results to the hierarchical structures derived from natural leaves:

“Our results may represent an important first step towards the design of novel artificial solar energy transduction systems based on natural paradigms, particularly based on exploring and mimicking the structural design. Nature still has much to teach us, and human ingenuity can modify the principles of natural systems for enhanced utility.”

Sourced and published by Henry Sapiecha 9th April 2010

University of North Texas Cool N2Car – Nitrogen powered prototype car


Designed, built, and tested by Dr. Carlos Ordonez (Physics), Dr. Mitty Plummer (Engineering Technology), and Dr. Rick Reidy (Department of Materials Science) of the University of North Texas , this developmental zero emission vehicle employs a cryogenic heat engine and is fueled by liquid nitrogen. This research was funded by the Texas Advanced Technology Program.

Liquid nitrogen vehicle

(Redirected from Liquid nitrogen economy)

liquid nitrogen vehicle is powered by liquid nitrogen, which is stored in a tank. The engine works by heating the liquid nitrogen in a heat exchanger, extracting heat from the ambient air and using the resulting pressurized gas to operate a piston or rotary engine.

Liquid nitrogen propulsion may also be incorporated in hybrid systems, e.g., battery electric propulsion and fuel tanks to recharge the batteries. This kind of system is called a hybrid liquid nitrogen-electric propulsion. Additionally, regenerative braking can also be used in conjunction with this system.

liquid nitrogen economy is a hypothetical proposal for a future economy in which the primary form of energy storage and transport is liquid nitrogen. It is proposed as an alternative to liquid hydrogen in some transport modes and as a means of locally storing energy captured fromrenewable sources. An analysis of this concept provides insight into the physical limits of all energy conversion schemes.

Description

Currently, most road vehicles are powered by internal combustion engines burning fossil fuel. If transportation is to be sustainable over the long term, the fuel must be replaced by something else produced by renewable energy. The replacement should not be thought of as an energy source; it is a means of transferring and concentrating energy, a “currency” or energy carrier.

Liquid nitrogen is generated by cryogenic or Stirling engine coolers that liquefy the main component of air, nitrogen (N2). The cooler can be powered by renewable-generated electricity or through direct mechanical work from hydro or wind turbines.

Liquid nitrogen is distributed and stored in insulated containers. The insulation reduces heat flow into the stored nitrogen; this is necessary because heat from the surrounding environment boils the liquid, which then transitions to a gaseous state. Reducing inflowing heat reduces the loss of liquid nitrogen in storage. The requirements of storage prevent the use of pipelines as a means of transport. Since long-distance pipelines would be costly due to the insulation requirements, it would be costly to use distant energy sources for production of liquid nitrogen. Petroleum reserves are typically a vast distance from consumption but can be transferred at ambient temperatures.

Liquid nitrogen consumption is in essence production in reverse. The Stirling engine or cryogenic heat engine offers a way to power vehicles and a means to generate electricity. Liquid nitrogen can also serve as a direct coolant for refrigeratorselectrical equipment and air conditioning units. The consumption of liquid nitrogen is in effect boiling and returning the nitrogen to the atmosphere.

Criticisms

Cost of production

Liquid nitrogen production is an energy-intensive process. Currently practical refrigeration plants producing a few tons/day of liquid nitrogen operate at about 50% of Carnot efficiency

Energy density of liquid nitrogen

Any process that relies on a phase-change of a substance will have much lower energy densities than processes involving a chemical reaction in a substance, which in turn have lower energy densities than nuclear reactions. Liquid nitrogen as an energy store has a low energy density. Liquid hydrocarbon fuels by comparison have a high energy density. A high energy density makes the logistics of transport and storage more convenient. Convenience is an important factor in consumer acceptance. The convenient storage of petroleum fuels combined with its low cost has led to an unrivaled success. In addition, a petroleum fuel is a primary energy source, not just an energy storage and transport medium.

The energy density — derived from nitrogen’s isobaric heat of vaporization and specific heat in gaseous state — that can be realised from liquid nitrogen at atmospheric pressure and zero degrees Celsius ambient temperature is about 97 watt-hours per kilogram (W-hr/kg). This compares with about 3,000 W-hr/kg for a gasoline combustion engine running at 28% thermal efficiency, 30 times the density of liquid nitrogen used at the Carnot efficiency

For an isothermal expansion engine to have a range comparable to an internal combustion engine, an 350-litre (92 US gal) insulated onboard storage vessel is required . A practical volume, but a noticeable increase over the typical 50-litre (13 US gal) gasoline tank. The addition of more complex power cycles would reduce this requirement and help enable frost free operation. However, no commercially practical instances of liquid nitrogen use for vehicle propulsion exist.

Frost formation

Unlike internal combustion engines, using a cryogenic working fluid requires heat exchangers to warm and cool the working fluid. In a humid environment, frost formation will prevent heat flow and thus represents an engineering challenge. To prevent frost build up, multiple working fluids can be used. This adds topping cycles to ensure the heat exchanger does not fall below freezing. Additional heat exchangers, weight, complexity, efficiency loss, and expense, would be required to enable frost free operation 

Safety

However efficient the insulation on the nitrogen fuel tank, there will inevitably be losses by evaporation to the atmosphere. If a vehicle is stored in a poorly ventilated space, there is some risk that leaking nitrogen depletes the level of oxygen in the air and causes asphyxiation. Since nitrogen is a colorless and odourless gas that already makes up 78 % of air, such a change is difficult to detect.

Cryogenic liquids are hazardous if spilled. Liquid nitrogen can cause frostbite and can make some materials extremely brittle.

Tanks

The tanks must be designed to safety standards appropriate for a pressure vessel, such as ISO 11439.

The storage tank may be made of:

The fiber materials are considerably lighter than metals but generally more expensive. Metal tanks can withstand a large number of pressure cycles, but must be checked for corrosion periodically.

Emission output

Like other non-combustion energy storage technologies, a liquid nitrogen vehicle displaces the emission source from the vehicle’s tail pipe to the central electrical generating plant. Where emissions-free sources are available, net production of pollutants can be reduced. Emission control measures at a central generating plant may be more effective and less costly than treating the emissions of widely-dispersed vehicles.

Advantages

Liquid nitrogen vehicles are comparable in many ways to electric vehicles, but use liquid nitrogen to store the energy instead of batteries. Their potential advantages over other vehicles include:

  • Much like electrical vehicles, liquid nitrogen vehicles would ultimately be powered through the electrical grid. Which makes it easier to focus on reducing pollution from one source, as opposed to the millions of vehicles on the road.
  • Transportation of the fuel would not be required due to drawing power off the electrical grid. This presents significant cost benefits. Pollution created during fuel transportation would be eliminated.
  • Lower maintenance costs
  • Liquid nitrogen tanks can be disposed of or recycled with less pollution than batteries.
  • Liquid nitrogen vehicles are unconstrained by the degradation problems associated with current battery systems.
  • The tank may be able to be refilled more often and in less time than batteries can be recharged, with re-fueling rates comparable to liquid fuels.

Disadvantages

The principal disadvantage is the inefficient use of primary energy. Energy is used to liquify nitrogen, which in turn provides the energy to run the motor. Any conversion of energy between forms results in loss. For liquid nitrogen cars, energy is lost when electrical energy is converted to liquid nitrogen.

Liquid nitrogen is not yet available in public refueling stations.

Details of this work were presented in July 1997 at the Cryogenic Materials Conference in Portland, Oregon. Questions about this program can be addressed to:

Dr. Carlos Ordonez
Department of Physics
PO Box 311427
University of North Texas
Denton, Texas 76203-1427
940-565-4860

Dr. Mitty Plummer
Dept. of Engineering Technology
PO Box 13198
University of North Texas
Denton, Texas 76203
940-565-2846
email: plummer@unt.edu

Dr. Rick Reidy
Dept. of Materials Science
PO Box 305310
University of North Texas
Denton, Texas 76203-5310
940-369-7115
email: reidy@unt.edu

Sourced and published by Henry Sapiecha 9th April 2010

Toshiba Enters Residential Solar Cell

System Market

Mar 2, 2010 12:57 Motonobu Kawai, Nikkei Electronics

Toshiba Corp will start selling residential solar cell systems using SunPower Corp’s monocrystalline silicon solar battery module April 1, 2010.

“We decided to enter the residential solar cell system market to promote our electric appliance and smart grid businesses,” the company said.

Toshiba plans to sell its solar cell systems together with its “SCiB” lithium-ion batteries and smart meters in the future.

All of the devices used for the residential solar cell system are purchased from outside companies, including the solar battery module, power conditioner (power conversion efficiency: 94%) and color display. Among them, SunPower’s solar battery module, “SPR-210N-WHT-J,” features a cell conversion efficiency as high as 21.5%, which Toshiba claims is the world’s highest level for commercialized solar cells.

The high conversion efficiency was realized by, for example, employing the monocrystalline silicon cell and the back-contact structure, in which electrodes are formed only on the back to increase the light-receiving area. The conversion efficiency as a module is 16.9%, and the maximum output is 210W.

The advantage of the back-contact structure is not only the enhancement of conversion efficiency. Because there is no electrode on the surface, electrodes do not glare when solar batteries are mounted. Some construction firms say that the electrodes on the surface of solar cells are a problem in designing, and this problem can be solved by employing the structure.

Toshiba’s employment of SunPower’s solar battery module will probably influence the business strategies of Japanese solar cell manufacturers. So far, Sanyo Electric Co Ltd’s HIT (heterojunction with intrinsic thin layer) solar cell has been known as a solar cell with a high conversion efficiency in Japan.

Sanyo and SunPower have been competing for the highest conversion efficiency at academic conferences. Also, as for the back-contact structure, Kyocera Corp is planning to release a product using polysilicon solar cells with the structure.

Sourced and published by Henry Sapiecha 4th March 2010

All-solid Li-polymer Battery Goes

Flexible, Slim

2010 21:39 Tetsuo Nozawa, Nikkei Electronics

Mie Industry Enterprise Support Center (MIESC) announced that it prototyped a “sheet-type all-solid polymer lithium storage battery” by using only printing processes.

The battery is safe, thin, flexible and large in area, MIESC said. It will be exhibited at the 1st Int’l Rechargeable Battery Expo, which will take place from March 3 to 5, 2010, in Tokyo.

The positive electrode layer, electrolyte layer and negative electrode layer of the lithium-ion battery are made by roll-to-roll processes. No separator is used between layers.

The positive electrode is made with LiFePO4 and a carbon complex while the negative electrode is made with Li4Ti5O12 and a complex of graphite, silicon, etc. A film made of a polymer material using a cross-linked polyethylene oxide is used for the electrolyte.

The polymer material is not in a gel state but in a solid state, and the battery does not use an organic electrolyte, which is flammable, ensuring high safety.

The A6-size lithium-ion battery is 450?m in thickness. Its initial capacity is 45mAh. When half of the capacity is discharged, its voltage is 1.8V. The discharge rate can be changed between 0.02C and 1.0C.

Existing all-solid lithium polymer storage batteries can hardly be used at a room temperature or below. But the new battery can be used even at a temperature from 0 to 25°C, MIESC said. The charge-discharge cycle is more than 100 and is still being evaluated, it said.

Sourced and published by Henry Sapiecha 4th March 2010

“Create the Future” Sustainable

Technologies Category Winner

The 2008 NASA Tech Briefs “Create the Future Design Contest,” presented by SolidWorks, recognized innovation in product design in six categories: Consumer Products, Machinery & Equipment, Medical, Safety & Security, Sustainable Technologies, and Transportation. Here is the winner of the Sustainable Technologies category, along with the two honorable mentions.

Efficient Air Conditioner

Lindsay Meek
Perth, Australia

efficient-air-conditioner-circuit

altThis design improves the energy efficiency of a residential air conditioner by replacing the traditional reciprocating compressor (bore and stroke) with a higher efficiency permanent magnet motor coupled to a scroll compressor. Recent advances in permanent magnet motors used in modern hybrid car electric drives and wind turbine generation have seen the incorporation of strong NdFeB magnets into the rotor, which greatly improves the motor efficiency. The compressor motor is then driven by a compact IGBT inverter stage with a motor controller, so motor current consumption can be optimized at the different operating speeds.

The other improvement that can be made is to replace the traditional refrigerant expansion valve with a similar scroll expander turbine coupled to a second permanent magnet generator. The decompression of the refrigerant gas through the turbine on its way to the condenser allows some of the work used to compress the gas to be recovered and converted back into electrical energy. The generator is connected to a second compact IGBT inverter stage with a motor controller, and can be controlled in conjunction with the compressor motor controller to regulate the pressure and flow rate of the gas through the system.

The two inverters are connected together via a common, high-voltage DC bus, so the electrical energy recovered from the decompression state can be reused by the compression stage, improving the overall efficiency of the refrigeration cycle. Finally, an AC-DC rectifier power supply is needed to provide the main work energy for the DC bus to keep the cycle operating. The above improvements should lower the power consumption by at least 30%.

For more information, contact the inventor at lindsaymeek@hotmail.com

Sourced and published by Henry Sapiecha 8th Sept 2009

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