March 6, 2014 | 1 Comment
Liechtenstein based nanoFLOWCELL AG has built a prototype vehicle equipped with flow cell battery power train. The car, called the QUANT e-Sportslimousine, is on display at the Geneva Motor Show. The firm claims the flow cell battery system supports an electric car driving range of between 400 to 600 km (249 to 373 miles) in the QUANT e-Sportlimousine prototype.
As a road worthy design the first automobile with a nanoFLOWCELL power train aroused great international media interest. This highly anticipated, revolutionary power train technology and energy-storage system could give new momentum to the electric vehicle industry.
Flow batteries or flow cells combine aspects of an electrochemical battery cell with those of a type of fuel cell. The difference is in the electrolyte. Electrolyte fluids in flow cells are usually metallic salts in aqueous solution that can be pumped from tanks through the battery. This forms a kind of battery cell with a cross-flow of electrolyte liquid. The advantage of this system is that the larger the storage tanks for the electrolyte fluid are, the greater the energy capacity. Keep in mind the concentration of an electrolytic solution contributes to the quantity of energy that it contains.
At the heart of the system, a membrane separates the two electrolytic solutions, but allows the electrical charge to pass through and thereby produce power for the drive train.
To charge or discharge nanoFLOWCELL’s flow battery the two different electrolytic solutions are pumped through the appropriate battery cell in which an electrode (anode or cathode) is located. A membrane separates the two electrolyte chambers of different chemistry. At a nominal voltage of 600 V and 50 A nominal current, the system in the lab is achieving continuous output of 30 kW.
According to nanoFLOWCELL, its flow battery has a specific energy of about 5 times that of a Li-ion battery (600 Wh/kg compared to ~120 Wh/kg). The company attributes the performance of the company’s flow battery to the characteristics of its newly-developed and unspecified electrolytic fluids made up of metallic salts at very high concentration.
Offering a bit more information, the company says that a large increase in the number of charge carriers in the electrolyte fluid within the battery significantly increased its performance compared to conventional redox flow-cells (about 5 times the specific energy and several orders of magnitude more specific power).
The company also claims its flow cells can go through 10,000 charging cycles with no noticeable memory effect and suffer almost no self-discharging. That would be over 27 years of service life at a daily charge frequency.
The QUANT e-Sportlimousine prototype carries two 200-liter (53 gallons US) tanks on board, for a total energy capacity of 120 kWh. The prototype’s energy consumption is about 20 kWh/100 km, when driving in the lower load range. Increasing the tank volume of the to 800 liters would be possible, the company says.
The catch is once the electrolytic fluids are discharged, the contents of both tanks must to be replaced. The prototype features a double tank system with dual filler necks, one for each electrolyte, to keep times for the electrolyte liquid replacement to a minimum.
The prototype uses four electric motor units (120 kW continuous, 170 kW peak per unit) for all-wheel drive with torque vectoring and two supercapacitor banks for energy storage. Peak torque per wheel is 2,900 N·m (2,139 lb-ft). The company says acceleration from 0 to 100 km/h is 2.8 seconds.
That where the international media attention motivates. These are supercar numbers.
A central VCU (vehicle control unit) is responsible for controlling the driving and charging currents throughout the entire power train. Supercapacitors provide the peak power to the four drive motors, and also serve as a general energy buffer for the vehicle’s electrical system and storage for regenerative braking energy.
There is more development coming. Last month nanoFLOWCELL AG announced a partnership with Bosch Engineering GmbH to further develop vehicle electronics for the QUANT e-Sportlimousine. The company is planning on producing four drivable prototypes in 2014.
nanoFLOWCELL AG, formerly JUNO Technology Products AG, reforming in late 2013, is a research and development center based in Vaduz, Liechtenstein. Their focus is on the advanced development of drive technology and the classification of flow-cell technology. The firm as Juno showed the earlier NLV Quant prototype at the Geneva Motor Show in 2009.
As noted, the performance is in the supercar range where costs can be as extreme as the performance. It also serves as a platform for development that may well trickle into the mass market. With range in the 300 mile zone and possibly decades of service life the trickle would be welcome, very welcome indeed.
University of Michigan (UM) researchers have invented colorful, see-through solar cells that may one day be used to make stained-glass windows, decorations and even shades that turn the sun’s energy into electricity. The technology may also be a solution to photocell orientation to the sun problem.
Jay Guo, a professor of electrical engineering and computer science, mechanical engineering, and macromolecular science and engineering at UM. Guo is lead author of a paper about the work newly published online in Scientific Reports.
Guo said the cells, believed to be the first semi-transparent, colored photovoltaics, have the potential to vastly broaden the use of solar energy resources. “I think this offers a very different way of utilizing solar technology rather than concentrating it in a small area. Today, solar panels are black and the only place you can put them on a building is the rooftop. And the rooftop of a typical high-rise is so tiny,” he said.
“We think we can make solar panels more beautiful – any color a designer wants. And we can vastly deploy these panels, even indoors.”
Suddenly, absent the garish black look, photovoltaic technology has some redeeming value – and may very well offer some aesthetic and intrinsic value beyond the energy production segment in their cost. This could dramatically change the cnosumer investment proposition.
Guo envisions them on the sides of buildings, as energy-harvesting billboards, window shades, and as a thin layer on homes and cities. Such an approach, he says, could be especially attractive in densely populated cities.
In a palm-sized American flag slide, the team demonstrated the technology.
“All the red stripes, the blue background and so on, they are all working solar cells,” Guo said.
The Stars and Stripes example achieves a 2 percent efficiency. A meter-square panel could generate enough electricity to power fluorescent light bulbs and small electronic gadgets, Guo said. State-of-the art organic cells in research labs are roughly 10 percent efficient.
The UM researchers are working to improve the efficiency numbers with new materials, but there will always be a tradeoff between beauty and utility in this case. Traditional black solar cells absorb all wavelengths of visible light. Guo’s cells are designed to transmit, or – in other versions – reflect certain colors, so by nature they’re reflecting energy from those wavelengths back out to our eyes rather than converting it to electricity.
Unlike other color solar cells, Guo’s don’t rely on dyes or microstructures that can blur the image behind them. The cells are mechanically structured to transmit certain light wavelengths. To get different colors, they varied the thickness of the semiconductor layer of amorphous silicon in the cells. The blue regions are six nanometers thick while the red is 31 (the team also made green, but that color isn’t in the flag).
Amorphous silicon is commonly used in screens on cell phones, laptops and large LCD screens, in addition to solar cells. They sandwiched an ultrathin sheet of it between two semi-transparent electrodes that could let light in and also carry away the electrical current.
One of the charge transport layers is made of an organic material. The combination of both organic and inorganic components makes a hybrid structure, letting the researchers make cells that are 10 times thinner than traditional amorphous silicon solar cells. The organic layer replaces a thick ‘doped’ circuit layer that would control the flow of electricity.
The ultrathin, hybrid design helps the cells hold their color and leads to a nearly 100 percent quantum efficiency. Quantum efficiency is different from overall efficiency. It refers to the percentage of light particles the device catches that lead to electrical current in that charge transport layer. Solar cells can leak current after this point, but researchers strive for a high number.
The cells’ hues don’t change based on viewing angle, which is important for several reasons. It means manufacturers could lock in color for precise pictures or patterns. It’s also a sign that the devices are soaking up the same amount of light regardless of where the sun is in the sky. Conventional solar panels pivot across the day to track rays.
“Solar energy is essentially inexhaustible, and it’s the only energy source that can sustain us long-term,” Guo said. “We have to figure out how to use as much of it as we can.”
Wait! Back up a moment, “a sign that the devices are soaking up the same amount of light regardless of where the sun is in the sky.”
This team has much more at hand than colors.
Physicists at the Harvard School of Engineering and Applied Sciences (SEAS) envision a device that would harvest energy from Earth’s infrared emissions into outer space. The idea is essentially new, even as we live live on an enormous natural nuclear fission reactor in the earth’s core. In the midst of a very cold winter the idea might seem strange, but planet earth is quite rich in energy resources with heat rising up from below being by far the largest.
Add to that we’re heated by the sun so our planet is warm compared to the frigid vacuum outside the atmosphere.
The Harvard researchers say their recent technological advances could move that heat imbalance and soon, be transformed into direct-current (DC) power, taking advantage of a vast and untapped energy source.
Principal investigator Federico Capasso, the Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering at Harvard SEAS said, “It’s not at all obvious, at first, how you would generate DC power by emitting infrared light in free space toward the cold. To generate power by emitting, not by absorbing light, that’s weird. It makes sense physically once you think about it, but it’s highly counterintuitive. We’re talking about the use of physics at the nanoscale for a completely new application.”
Capasso is a world-renowned expert in semiconductor physics, photonics, and solid-state electronics. He co-invented the infrared quantum-cascade laser in 1994, pioneered the field of bandgap engineering, and demonstrated an elusive quantum electrodynamical phenomenon called the repulsive Casimir force – work for which he has received the SPIE Gold Medal, the European Physical Society Prize for Quantum Electronics and Optics, and the Jan Czochralski Award for lifetime achievement. His research team seems to specialize in rigorously questioning other physicists’ assumptions about optics and electronics.
“The mid-IR has been, by and large, a neglected part of the spectrum,” says Capasso. “Even for spectroscopy, until the quantum cascade laser came about, the mid-IR was considered a very difficult area to work with. People simply had blinders on.”
Now, Capasso and his research team are proposing something akin to a photovoltaic solar panel, but instead of capturing incoming visible light, the device would generate electric power by releasing infrared light.
Lead author Steven J. Byrnes (AB ’07), a postdoctoral fellow at SEAS explains, “Sunlight has energy, so photovoltaics make sense; you’re just collecting the energy. But it’s not really that simple, and capturing energy from emitting infrared light is even less intuitive. It’s not obvious how much power you could generate this way, or whether it’s worthwhile to pursue, until you sit down and do the calculation.” Romain Blanchard PhD. is also a coauthor of the paper.
As it turns out, the power is modest but real.
As Byrnes points out, “The device could be coupled with a solar cell, for example, to get extra power at night, without extra installation cost.”
To show the range of possibilities, Capasso’s group suggests two different kinds of radiating energy harvesters: one that is analogous to a solar thermal power generator, and one that is analogous to a photovoltaic cell. However, both would run in reverse.
The first type of device would consist of a “hot” plate at the temperature of the Earth and air, with a “cold” plate on top of it. The cold plate, facing upward, would be made of a highly heat radiating material that cools by very efficiently radiating heat to the sky. Based on measurements of infrared emissions in Lamont, Oklahoma (as a case study), the researchers calculate that the heat difference between the plates could generate a few watts per square meter, day and night. Keeping the “cold” plate cooler than the ambient temperature would be difficult, but this device illustrates the general principle: differences in temperature generate work.
“This approach is fairly intuitive because we are combining the familiar principles of heat engines and radiative cooling,” says Byrnes.
The second proposed device relies on temperature differences between nanoscale electronic components – diodes and antennas – rather than a temperature that you could feel with your hand.
“If you have two components at the same temperature, obviously you can’t extract any work, but if you have two different temperatures you can,” says Capasso. “But it’s tricky; at the level of the electron behaviors, the explanation is much less intuitive.”
“The key is in these beautiful circuit diagrams,” he adds (see image). “We found they had been considered before for another application – in 1968 by J.B. Gunn, the inventor of the Gunn diode used in police radars – and been completely buried in the literature and forgotten. But to try to explain them qualitatively took a lot of effort.”
Simply put, components in an electrical circuit can spontaneously push current in either direction; this is called electrical noise. Gunn’s diagrams show that if a valve-like electrical component called a diode is at a higher temperature than a resistor, it will push current in a single direction, producing a positive voltage. Capasso’s group suggests that the role of the resistor could be played by a microscopic antenna that very efficiently emits the Earth’s infrared radiation toward the sky, cooling the electrons in only that part of the circuit.
The result, says Byrnes, is that “you get an electric current directly from the radiation process, without the intermediate step of cooling a macroscopic object.”
Thus the research team says in the paper a single flat device could be coated in many of these tiny circuits, pointed at the sky, and used to generate power.
One suspects the device could be designed and used in any circumstance where the heat could be radiated away.
The optoelectronic approach is quite new and could be feasible in light of the recent technological developments advances in plasmonics, small-scale electronics, new materials like graphene, and nanofabrication. The Harvard team says a strength of their research is that it clarifies the remaining challenges.
Byrnes noted, “People have been working on infrared diodes for at least 50 years without much progress, but recent advances such as nanofabrication are essential to making them better, more scalable, and more reproducible.”
The idea isn’t perfected just yet. Byrnes explains that even with the best modern infrared diodes, there is a problem. “The more power that’s flowing through a single circuit, the easier it is to get the components to do what you want. If you’re harvesting energy from infrared emissions, the voltage will be relatively low. That means it’s very difficult to create an infrared diode that will work well,” he said.
Engineers and physicists, including Byrnes, are already considering new types of diodes that can handle lower voltages, such as tunnel diodes and ballistic diodes. Another approach would be to increase the impedance of the circuit components, thereby raising the voltage to a more practical level. The solution might require a little of both, Byrnes predicts.
Then there is the problem faced by other ideas that offer ways to harvest heat. The frequencies of operation are astounding. Byrnes said, “Only a select class of diodes can switch on and off 30 trillion times a second, which is what we need for infrared signals. We need to deal with the speed requirements at the same time we deal with the voltage and impedance requirements.”
Byrnes offers, “Now that we understand the constraints and specifications, we are in a good position to work on engineering a solution.”
Others are hard at the problem as well. Something is sure to come out solving the frequency speed matter.
The key in this is combining the familiar principles of heat engines and radiative cooling in a totally new way. Its a new field now, just invented by the Harvard team.
Lewis G. Larsen one namesake of the famed Low Energy Nuclear Reaction (LENR) version of Cold Fusion and now heading Lattice Energy LLC in Chicago is reporting a claim to have developed a process for energy production, utilizing LENR that, as a byproduct of neutron captures on tungsten, will create a mix of precious metals.
Lattice Energy was founded back in 2001. Larsen is part of a team that learned from cold fusion’s mistakes, saying with respect to cold fusion, “Their heat production measurements were right, but their conclusions about the heat being produced by a fusion process were completely wrong.”
Lattice’s work hinges on the Widom-Larsen theory. Larsen points out the theory and recent advances in nanotechnology has brought LENR advances. “Nanotechnology and LENR are joined at the hip”, said Larsen. “It is one of the reasons why this could not be done back in 1989-90. Before our work, nobody had a grasp on the theory of neutron creation from protons and electrons in tabletop apparatus; nor on exactly how to apply advanced nanotechnology to build well-performing prototype devices.”
The Lattice team has brought in the know-how of experts from a variety of disciplines including electro-dynamics, quantum electro-dynamics, nuclear physics and solid state physics. The firm believes the development of a theoretical foundation is now ready to be prototyped and put to the test.
The goal of Lattice is to build high performance thermal sources with outputs ranging from single watts to 100 kilowatts, the ultimate application being the use of LENR devices in automobiles. Patents have been filed and some have been issued. At this point, financing is provided by insiders and several angel investors, but larger amounts of capital are needed to take the technology to its next level.
Larsen’s theory that gold, platinum and several other metals can be created by the LENR process is based on findings by Japanese physicist Prof. Hantaro Nagaoka. Nagoda successfully transmuted tungsten into gold in 1924. Nagaoka’s results have been verified by several institutions in recent independent experiments but so far there has been no effort to commercialize the process.
Additionally, the Ukrainians managed to transmute to heavier elements a few years back by simply impacting materials at extreme velocity in very tiny amounts at great cost. It can be done.
Larsen said, “Now that the LENR transmutation process is well understood the use of nanotechnology may change all that.”
Larsen explains. “The neutron-catalyzed LENR process follows rows of the periodic table of elements”, meaning that heavier metals than the starting targets will be created. The work published by Larsen and his team suggests that a tungsten target example would absorb neutrons and gradually be transmuted to gold, platinum and other platinum group metals. “And because LENR products are not dangerously radioactive, conventional metal recovery processes can be utilized,” he said.
Larsen is convinced element transmutation may be possible, but, “Can we scale this up to a commercial process that makes money?” he said.
The transmutation from lead to gold has been mankind’s dream for hundreds of years. We will see as this group has the skills and staying power to keep going.
Imagine, a power system that has precious metals as a waste product. Humanity might be very lucky this time.
February 26, 2014 | Leave a Comment
University of Wisconsin-Madison researchers have combined cheap, oxide-based materials to split water into hydrogen and oxygen gases using solar energy with a solar-to-hydrogen conversion efficiency of 1.7 percent, the highest reported for any oxide-based photoelectrode system. The big deal is the lost cost angle.
Generating electricity is not the only way to turn sunlight into energy, solar can also drive reactions to create chemical fuels, such as hydrogen, which would store as a fuel. That could power most anything by either combustion or a fuel cell.
So far the problem with solar fuel production is the cost of producing the sun-capturing semiconductors and the catalysts to generate fuel. The most efficient materials are far too expensive to produce fuel at a price that can compete with gasoline.
Kyoung-Shin Choi, a chemistry professor at the University of Wisconsin-Madison explains, “In order to make commercially viable devices for solar fuel production, the material and the processing costs should be reduced significantly while achieving a high solar-to-fuel conversion efficiency.”
Choi and postdoctoral researcher Tae Woo Kim’s study paper was published last week in the journal Science. There they describe combining cheap, oxide-based materials to split water into hydrogen and oxygen gases using solar energy with a solar-to-hydrogen conversion efficiency of 1.7 percent, the highest reported for any oxide-based photoelectrode system.
That compares to photovoltaic closing in on 30 percent, yet green plants, as the new research materials, are in low single digits, too.
Choi created solar cells from bismuth vanadate using electrodeposition, the same process employed to make gold-plated jewelry or surface-coat car bodies, to boost the compound’s surface area to a remarkable 32 square meters for each gram.
“Without fancy equipment, high temperature or high pressure, we made a nanoporous semiconductor of very tiny particles that have a high surface area. More surface area means more contact area with water, and, therefore, more efficient water splitting,” explained Choi, whose work is supported by the National Science Foundation.
Bismuth vanadate needs a hand in speeding the reaction that produces fuel, and that’s where the paired catalysts come in.
While there are many research groups working on the development of photoelectric semiconductors, and many working on the development of water-splitting catalysts, according to Choi, the semiconductor-catalyst junction gets relatively little attention.
“The problem is, in the end you have to put them together,” she says. “Even if you have the best semiconductor in the world and the best catalyst in the world, their overall efficiency can be limited by the semiconductor-catalyst interface.”
Choi and Kim exploited a pair of cheap and somewhat flawed catalysts – iron oxide and nickel oxide – by stacking them on the bismuth vanadate to take advantage of their relative strengths.
“Since no one catalyst can make a good interface with both the semiconductor and the water that is our reactant, we choose to split that work into two parts,” Choi says. “The iron oxide makes a good junction with bismuth vanadate, and the nickel oxide makes a good catalytic interface with water. So we use them together.”
The dual-layer catalyst design enabled simultaneous optimization of semiconductor-catalyst junction and catalyst-water junction.
“Combining this cheap catalyst duo with our nanoporous high surface area semiconductor electrode resulted in the construction of an inexpensive all oxide-based photoelectrode system with a record high efficiency,” Choi says.
She expects the basic work done to prove the efficiency enhancement by nanoporous bismuth vanadate electrode and dual catalyst layers will provide labs around the world with fodder for leaps forward.
“Other researchers studying different types of semiconductors or different types of catalysts can start to use this approach to identify which combinations of materials can be even more efficient,” says Choi, whose lab is already tweaking their design. “Which some engineering, the efficiency we achieved could be further improved very fast.”
The hydrogen economy has more hope now. For now with fuel cells still quite expensive combustion will have to do. But hydrogen can run engines and heat water, homes and run lots of business. As efficiency climbs hydrogen will get more interesting at the consumer level.