610fwd Future Energy eNews
- Mar 29, 2010
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FUTURE ENERGY eNEWS
Last Friday, I was in Houston for an invitation-only panel discussion event with the CEO Peter Voser of Royal Dutch Shell called "Our Energy Future" which was also webcast. I had the opportunity to ask him about the near future when their product will be obsolete. However, the answer that was forthcoming from Mr. Voser was evasive and condescending, with overtures to the "consumer demand" and their internal study that predicts people will still buy gasoline in 2050. Even with their biodiesel and biogasoline pilot plants, I found out that Shell has no desire to scale up ecofriendly fuel to replace their hugely polluting petroleum product, amounting to 40% of the U.S. energy consumption. Even as a whole country like Brazil now powers their cars with sugarcane biodiesel and more electric cars than ever crowd the auto shows, Shell's CEO proved to be unmoved by any moral responsibility for the company's extensive pollution of the planet and instead, seemed determined to wrench every last dollar from U.S. consumers addicted to their "speed" by the gallon, while in the background, the clearly visible brown smog of NO2 car exhaust on the skyline chokes every major city like Houston and the car exhaust CO2 keeps heating up the planet. Surprisingly, the entrepreneur Vinod Khosla on the panel made it very clear with several examples that revolutionary products only take about five (5) years to entirely replace an inferior product previously thought to be untouchable. I guess that is what Shell made clear they are waiting for before they will change. They must be hoping that Bloom boxes (see story #1)will never become available in a year or so for every home at around $3000, thus powering a revolutionary stampede sale for plug-in electric cars that are recharged by home-grown electricity or charging stations along the road for almost no cost. That could never happen right?
Thomas Valone, PhD, PE
IN THIS ISSUE
03 March 2010 by Colin Barras, New Scientist magazine.
AN ENERGY revolution started last week that will see fridge-sized boxes in every building generate electricity on demand from natural gas or biogas. At least, that was the story told by the publicity and excitement around the celebrity-backed debut of Californian company Bloom Energy.
The firm's solid-oxide fuel cells (SOFCs), dubbed "Bloom boxes" by the media, are already being trialled by eBay, Google and Coca-Cola, and Bloom says they can shrink a building's carbon footprint by half.
Bloom's claims are plausible, despite few details being released. But the company isn't the vanguard of a revolution in electricity supply; the revolution has already begun. Several more experienced firms already make fuel cells much like Bloom's, and some are cheap enough to be heading into homes already.
The technology at the heart of the excitement looks unspectacular: a chunk of ceramic. But the right ceramic can be an electrolyte that allows the movement of ions needed to combine natural gas with oxygen from the air without burning, driving power around an external circuit in the process. No expensive catalyst is required - an advantage over hydrogen fuel cells, most of which need platinum to work.
An SOFC must be heated to reduce the ceramic's resistance and start the reaction, which then generates its own heat. Despite that, Bloom claims its cell can power a building more efficiently than an electricity grid, which loses power in transmission and is fed by power plants that waste heat from combustion.
Bloom's boxes are impressively compact, but so are most SOFCs. As far as innovation goes, the firm will say only that the chunk of ceramic inside is painted with "secret inks" that act as anode and cathode.
That suggests its interior is held together by the ceramic, says Helge Holm-Larsen of Topsoe Fuel Cell in Lyngby, Denmark, requiring a relatively thick chunk of it that would need heating to at least 900 °C to operate. That cuts efficiency, although a fuel cell serving a constant demand would not need to start from cold very often.
For more variable demands, like those of an office or home, cutting the start-up penalty is crucial. Topsoe uses an enlarged anode to support its own SOFC's interior, allowing a smaller electrolyte that operates effectively at 750 °C, says Holm-Larsen.
Fuel cells can be even cooler, though. Those from Ceres Power in Crawley, UK, operate below 600 °C thanks to a custom electrolyte of lower resistance. The temperature is low enough for steel welds to hold the device together inside.
Domestic boilers powered by Ceres's cells are cheap and advanced enough for 37,500 of them to be heading to homes in the UK this year, as part of a four-year programme for customers of energy supplier British Gas. Once installed, the cell will generate most of a home's electricity, says Ceres.
The 60 Minutes Bloom Box Segments are below.
2) Tiny Tubular Generators
by Saswato R. Das // March 2010 , IEEE Spectrum,
To the many properties of carbon nanotubes, we can now add electrical generation
A team of scientists led by chemical engineering professor Michael Strano of MIT may have stumbled on a new way to produce electricity using carbon nanotubes, as they explain in a recent issue of Nature Materials.
Since their discovery in the early 1990s, carbon nanotubes have turned out to be remarkably versatile for research applications. These thin, cylindrical carbon molecules, typically nanometers in diameter, have a remarkably large number of electrical and structural properties. They are used to reinforce high-end tennis rackets and bicycle handlebars, to craft Lilliputian nanomotors, and to modulate signals in electronics. Potential applications include transistors for computer circuits (demonstrated by IBM), computer memories (being developed by Nantero), and solar cells. In the past couple of years, scientists have also demonstrated loudspeakers and a tiny "nanoradio" made with nanotubes.
Strano and his collaborators coated multiwalled carbon nanotubes with cyclotrimethylene trinitramine (CNT), a chemical fuel. When they shot a laser beam or produced a high-voltage electrical spark at one end of a CNT-coated nanotube bundle, the CNT ignited, and a speedy thermal wave was created that traveled through the nanotubes much as a flame travels through a fuse. This wave in turn produced a burst of electricity by pushing electrons through the nanotubes in front of it. (Electricity is produced by the movement of electrons.)
This effect has not been observed before and it's generating quite a bit of interest among scientists and engineers. "Nanotubes are usually regarded as uninteresting for thermoelectric energy conversion because of their very large thermal conductivity. Paradoxically, it is precisely this good thermal conductivity that appears to enable the effect," says Natalio Mingo, a senior scientist at the French Atomic Energy Commission's Laboratory for Innovation in New Energy Technologies and Nanomaterials, in Grenoble, France.
Strano says that as the CNT burns, the heat is directed into the nanotube bundle in a "wicking" effect, so that it travels 10 000 times as fast as it can in the fuel itself. "Nanotubes are extremely good at conducting heat along their length," he explains. "They can conduct heat more than a factor of 100 times faster than a metal."
The entire phenomenon is a combination of combustion and electrical power generation, which Strano calls "thermopower waves." He says that the electrical energy produced by the nanotubes is 100 times as great as what would be produced in a lithium ion battery if you took an equivalent weight of the battery. The exact mechanism by which the electricity is produced is still not properly understood.
"Unlike a battery or supercapacitor, there is zero self-discharge with this approach. Plus, it works well for powering small things, since the power density is very large," Strano says.
Combustion waves have been studied for more than a century. Strano and his collaborators predicted recently that combustion waves could be guided by a nanotube or nanowire, which in turn could push an electrical current along in front of it. However, in the experiments they performed, they reported that "the amount of power released is much greater than predicted."
"There's something else happening here," he says. "We call it 'electron entrainment,' since part of the current appears to scale with wave velocity."
Whatever the mechanism, independent experts are intrigued. "Even though the demonstrated efficiencies are still lower than 1 percent, the experiment is quite spectacular," says Mingo.
Strano envisions such potential applications as transponders, beacons, and actuators in cases where a burst of energy is needed. But the jury needs more evidence. "It will be trickier to motivate an application, especially because scaling degrades the figures of merit for the system in all of the proposed application areas," says electrical engineering professor John Kymissis of Columbia University, who is impressed with the experiment.
Strano thinks that thermopower could be used to create better fuel cells. "The conventional fuel cell has been around since the 1800s, but corrosive fuels and catalytic deactivation have been a hurdle," he says. "Thermopower waves could be a very simple alternative."
About the Author
Saswato R. Das is a science reporter in New York City. In the March 2010 issue he wrote about how Russian scientists had solved the mystery of superinsulators.
3) A Hoist To The Heavens
BY Bradley Carl Edwards // August 2005 , IEEE Spectrum , http://spectrum.ieee.org/aerospace/space-flight/a-hoist-to-the-heavens
Ed. Note: The technology for the space elevator has progressed very little since this excellent article was published, except that carbon nanotube ROPE and RIBBON have now been patented, which means the strongest fiber known to man for the space elevator can now be manufactured in continuous lengths and spooled. - TV
A space elevator could be the biggest thing to happen since the Stone Age, but can we build one?
Rockets are getting us nowhere fast. Since the dawn of the space age, the way we get into space hasn't changed: we spend tens or hundreds of millions of dollars on a rocket whose fundamental operating principle is a controlled chemical explosion. We need something better, and that something is a space elevator--a superstrong, lightweight cable stretching 100 000 kilometers from Earth's surface to a counterweight in space. Roomy elevator cars powered by electricity would speed along the cable. For a fraction of the cost, risk, and complexity of today's rocket boosters, people and cargo would be whisked into space in relative comfort and safety.
It sounds like a crazy idea, and indeed the space elevator has been the stuff of science fiction for decades. But if we want to set the stage for the large-scale and sustained exploration and colonization of the planets and begin to exploit solar power in a way that could significantly brighten the world's dimming energy outlook, the space elevator is the only technology that can deliver. It all boils down to dollars and cents, of course. It now costs about US $20 000 per kilogram to put objects into orbit. Contrast that rate with the results of a study I recently performed for NASA, which concluded that a single space elevator could reduce the cost of orbiting payloads to a remarkably low $200 a kilogram and that multiple elevators could ultimately push costs down below $10 a kilogram. With space elevators we could eventually make putting people and cargo into space as cheap, kilogram for kilogram, as airlifting them across the Pacific.
The implications of such a dramatic reduction in the cost of getting to Earth orbit are startling. It's a good bet that new industries would blossom as the resources of the solar system became accessible as never before. Take solar power: the idea of building giant collectors in orbit to soak up some of the sun's vast power and beam it back to Earth via microwaves has been around for decades. But the huge size of the collectors has made the idea economically unfeasible with launch technologies based on chemical rockets. With a space elevator's much cheaper launch costs, however, the economics of space-based solar power start looking good.
A host of other long-standing space dreams would also become affordable, from asteroid mining to tourism. Some of these would depend on other space-transportation technologies for hauling people and cargo past the elevator's last stop in high-Earth orbit. But physics dictates that the bulk of the cost is dominated by the price of getting into orbit in the first place. For example, 95 percent of the mass of each mighty Saturn V moon rocket was used up just getting into low-Earth orbit. As science-fiction author Robert A. Heinlein reportedly said: "Once you get to Earth orbit, you're halfway to anywhere in the solar system." With the huge cost penalty of traveling between Earth and orbit drastically reduced, it would actually be possible to quarry mineral-rich asteroids and return the materials to Earth for less than what it now costs, in some cases, to rip metal ores out of Earth's crust and then refine them. Tourism, too, could finally arrive on the high frontier: a zero-gravity vacation in geostationary orbit, with the globe spread out in a ceaselessly changing panoply below, could finally become something that an average person could experience. And for the more adventurous, the moon and Mars could become the next frontier.
So why can't we do all this with rockets? And why is the space elevator so cheap?
The answer is that chemical rockets are inherently too inefficient: only a tiny percentage of the mass at liftoff is valuable payload. Most of the rest is fuel and engines that are either thrown away or recycled at enormous expense. Nuclear and electric rockets promise huge improvements in efficiency and will be vital to the future of solar system exploration, but they are impractical as a means of getting off Earth: they either don't produce enough thrust to overcome gravity or pose a potentially serious radiation hazard. On the other hand, space elevators could haul tons of material into space all day, every day. And the core of the space elevator--the cable--could be constructed from cheap, plentiful materials that would last for decades. A space elevator would be amazingly expensive or absurdly cheap--depending on how you look at it. It would cost about $6 billion in today's dollars just to complete the structure itself, according to my study. Costs associated with legal, regulatory, and political aspects could easily add another $4 billion, but these expenses are much harder to estimate.
Building such an enormous structure would probably require treaty-level negotiations with the international community, for example. A $10 billion price tag, however, isn't really extraordinary in the economics of space exploration. NASA's budget is about $15 billion a year, and a single shuttle launch costs about half a billion dollars. The construction schedule could conceivably be as short as 10 years, but 15 years is a more realistic estimate when technology development, budget cycles, competitive selection, and other factors are accounted for. After the first elevator was built, its initial purpose would be to lift into space the materials for a second elevator. As with conventional elevators in tall buildings, practical realities make it almost certain that more than one elevator would be constructed. With separate "up" and "down" elevators, you could haul cargo and passengers simultaneously to and from space. The second elevator would be much easier and cheaper to build than the first, not only because it could make use of the first elevator but because all the R&D and much of the supporting infrastructure would already be complete. With these savings, I estimate that a second elevator would cost a fraction of the first one--as little as $3 billion dollars for parts and construction.
In my studies, I have found that the schedule for more elevators, after the first, could be compressed to as little as six months. The first country or consortium to finish an elevator would therefore gain an almost unbeatable head start over any competitors. Five years ago, the space elevator was considered science fiction by most of the space community. With the advent of carbon-nanotube composites and the conclusions of recent studies, the space elevator concept is moving toward mainstream acceptance. The estimated operational cost for the first elevator is several hundred dollars per kilogram to any Earth orbit, the moon, or Mars, a drop of two orders of magnitude over the cost of current launch technologies. With the completion of subsequent elevators, the cost would drop even further, to a few dollars per kilogram.
So how exactly would it work? Springing out from an anchor point on the equator, the space elevator cable would rise straight up, passing through geostationary orbit at 36 000 km and continuing for another 64 000 km until it terminates in a 600-ton counterweight. The cable would be held up in a manner similar to that which holds a string taut as a weight tied to it is swung in a circle. The key detail that would make the elevator work would be the fact that its center of gravity would be at the geostationary orbit mark, forcing the entire structure to move in lockstep with Earth's rotation.
Electrically powered elevator cars, which I call climbers, would crawl up the cable, carrying people or cargo. Each car would weigh about 20 tons fully loaded, of which about 13 tons would be payload. These payloads could be in the form of inflatable structures, like those proposed for the International Space Station, with about 900 cubic meters of space, or roughly as much as a five-bedroom house. For passengers, a climber would be like a space-going cruise ship; there would be small sleeping quarters, a tiny kitchen and other amenities, and, of course, windows with some of the most stunning views in the solar system. Ascending at 190 km per hour, the climbers would reach geostationary orbit in about eight days [see illustration, ].
The biggest challenges to building an elevator are finding a strong enough cable material and then designing and constructing the cable. The cable would be the heart of the elevator, and finding the right stuff for its manufacture has historically been the main obstacle to turning the elevator into reality. In fact, the space elevator concept is an old one--Russian scientist Konstantin Tsiolkovsky proposed the basic concept more than a century ago. The idea resurfaced in the 1960s, but at the time there was no material in existence strong enough for the cable. To support its own weight as well as the weight of climbers, the cable has to be built out of something that is incredibly light and yet so strong that it makes steel seem like soft-serve ice cream. The space elevator faded back into the realm of sci-fi. Then, in 1991, Japanese researcher Sumio Iijima discovered carbon nanotubes. These are long, narrow, cylindrical molecules; the cylinder walls are made of carbon atoms, and the tube is about 1 nanometer in diameter.
In theory, at least, carbon-nanotube-based materials have the potential to be 100 times as strong as steel, at one-sixth the density. This strength is three times as great as what is needed for the space elevator. The most recent experiments have produced 4-centimeter-long pieces of carbon-nanotube materials that have 70 times the strength of steel. Outside the lab, bulk carbon-nanotube composite fibers have already been made in kilometer-long lengths, but these composite fibers do not yet have the strength needed for a space elevator cable. However, we think we know how to get there. There are two methods being examined at academic institutions and at my company, Carbon Designs Inc., in Dallas. The first approach is to use long composite fibers, which are about as strong as steel and have a composition of 3 percent carbon nanotubes, the rest being a common plastic polymer. By improving the ability of the carbon-nanotube wall to adhere to other molecules and increasing the ratio of nanotubes to plastic in the fiber to 50 percent, it should be possible to produce fibers strong enough for the space elevator cable.
The second approach is to make the cable out of spun carbon-nanotube fibers. Here, long nanotubes would be twisted together like conventional thread. This method has the potential to produce extremely strong material that could meet the demands of the space elevator. Both processes could be proved in the next few years. With a suitable material on the horizon, the next question is the design of the cable itself. Prior to 2000, in both science fiction and the scant technical literature, the space elevator was a massive system--with huge cables 10 meters in diameter or inhabited towers more than a kilometer across. These systems also required snagging asteroids to use as the counterweight at the end of the elevator. Suffice it to say, it's all well beyond our current engineering capabilities--mechanical, electrical, material, and otherwise.
IN MY STUDY , I sought a design that could be built soon and could annually lift 1500 tons, or 10 time
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