The students of College of Engineering Trivandrum had the rare opportunity to interact with the CEO of NEX Robotics Dr.Anant Malewar on January 15th 2014 at Seminar Hall of Department of Electrical and Electronics Engineering College of Engineering Trivandrum
The session began by a prayer and then the Chapter Advisor of IEEE RAS student Chapter College of Engineering Trivandrum Dr. Jisha V.R delivered the welcome address.
Next was the talk on State of Art of the robotics by Dr. Anant Malewar CEO of Nex Robotics. He highlighted the need to bridge the gap with robotics and academics in India. He also mentioned about the topic Mobile Robots –Past, Present, Future, and also demonstrated the different kind of robots and their working . He added that the Nex Robotics system has a good future in INDIA and mentioned about the career in Nex Robotics. The talk was highly inspirational for all Robotics enthusiastic students in the student chapter. And the talk was concluded with the question and answering session.
Taking apart the shattered power station and its three melted nuclear cores will require advanced robotics
A radiation-proof superhero could make sense of Japan’s Fukushima Daiichi nuclear power plant in an afternoon. Our champion would pick through the rubble to reactor 1, slosh through the pooled water inside the building, lift the massive steel dome of the protective containment vessel, and peek into the pressure vessel that holds the nuclear fuel. A dive to the bottom would reveal the debris of the meltdown: a hardened blob of metals with fat strands of radioactive goop dripping through holes in the pressure vessel to the floor of the containment vessel below. Then, with a clear understanding of the situation, the superhero could figure out how to clean up this mess.
Unfortunately, mere mortals can’t get anywhere near that pressure vessel, and Japan’s top nuclear experts thus have only the vaguest idea of where the melted fuel ended up in reactor 1. The operation floor at the top level of the building is too radioactive for human occupancy: The dose rate is 54 millisieverts per hour in some areas, a year’s allowable dose for a cleanup worker. Yet, somehow, workers must take apart not just the radioactive wreck of reactor 1 but also the five other reactors at the ruined plant.
This decommissioning project is one of the biggest engineering challenges of our time: It will likely take 40 years to complete and cost US $15 billion. The operation will involve squadrons of advanced robots, the likes of which we have never seen.
Nothing has been the same in Japan since 11 March 2011, when one of history’s worst tsunamis flooded Fukushima Daiichi, crippled its emergency power systems, and triggered a series of explosions and meltdowns that damaged four reactors. A plume of radioactive material drifted over northeast Japan and settled on towns, forests, and fields, while plant workers scrambled to pour water over the nuclear cores to prevent further radioactive releases. Nine months later, the Tokyo Electric Power Co. (TEPCO), the utility company that operates the plant, declared the situation stable.
Stability is a relative concept: Although conditions at Fukushima Daiichi aren’t getting worse, the plant is an ongoing disaster scene. The damaged reactor cores continue to glow with infernal heat, so plant employees must keep spraying them with water to cool them and prevent another meltdown. But the pressure vessels and containment vessels are riddled with holes, and those leaks allow radioactive water to stream into basements. TEPCO is struggling to capture that water and to contain it by erecting endless storage tanks. The reactors are kept in check only by ceaseless vigilance.
TEPCO’s job isn’t just to deal with the immediate threat. To placate the furious Japanese public, the company must clean up the site and try to remove every trace of the facility from the landscape. The ruin is a constant reminder of technological and managerial failure on the grand scale, and it requires a proportionally grand gesture of repentance. TEPCO officials have admitted frankly that they don’t yet know how to accomplish the tasks on their 40-year road map, a detailed plan for decommissioning the plant’s six reactors. But they know one thing: Much of the work will be done by an army of advanced robots, which Japan’s biggest technology companies are now rushing to invent and build.
Here’s some more bad news: Chernobyl and Three Mile Island, the only other commercial-scale nuclear accidents, can’t teach Japan much about how to clean up Fukushima Daiichi. The Chernobyl reactor wasn’t dismantled; it was entombed in concrete. The Three Mile Island reactor was defueled, but Lake Barrett, who served as site director during that decommissioning process, says the magnitude of the challenge was different. At Three Mile Island the buildings were intact, and the one melted nuclear core remained inside its pressure vessel. “At Fukushima you have wrecked infrastructure, three melted cores, and you have some core on the floor, ex-vessel,” Barrett says. Nothing like Fukushima, he declares, has ever happened before.
Barrett, who is now a consultant for the Fukushima cleanup, says TEPCO is taking the only approach that makes sense: “You work from the outside in,” he says, dealing with all the peripheral problems in the buildings before tackling the heart of the matter, the melted nuclear cores. During the first three years of the cleanup, TEPCO has been surveying the site to create maps of radiation levels. The next step is removing radioactive debris and scrubbing radioactive materials off walls and floors. Spent fuel must be removed from the pools in the reactor buildings; leaks must be plugged. Only then will workers be able to flood the containment structures so that the melted globs of nuclear fuel can safely be broken up, transferred to casks, and carted away.
Many of the technologies necessary for the decommissioning already exist in some form, but they must be adapted to fit the unique circumstances of Fukushima Daiichi. “It’s like in the 1960s, when we wanted to put a man on the moon,” says Barrett. “We had rocketry, we had physics, but we had never put all the technologies together.” Just as with the moon shot, there is no guarantee that this epic project can be accomplished. But faced with the wrath of the Japanese people, TEPCO has no choice but to try.
To begin the first step—inspection—TEPCO sent in robots to map the invisible hot spots throughout the smashed reactor buildings. The first to arrive were the U.S.-made PackBot and Warrior, hastily shipped over from iRobot Corp. of Bedford, Mass. But Japan is justly proud of its own robotics industry, so the question arose, Why didn’t TEPCO have robots ready to respond in a nuclear emergency? Yoshihiko Nakamura, a University of Tokyo robotics professor, has the dispiriting answer. The government did fund a program on robotics for nuclear facilities in 2000, following a deadly accident at a uranium reprocessing facility. But that project was shut down after a year. “[The government] said this technology is immature, and it is not applicable for the nuclear systems, and the nuclear systems are already 100 percent safe,” Nakamura explains. “They didn’t want to admit that the technology should be prepared in case of accident.”
Still, some roboticists in Japan carried on their own research despite the government’s indifference. In the lab of Tomoaki Yoshida, a roboticist at the Chiba Institute of Technology, near Tokyo, robots have learned to crawl over rubble and to climb up and down steps. These small tanks roll on a flexible series of treads, which can be lifted or lowered individually to allow the bot to manage stairs.
After the Fukushima accident, Yoshida’s academic research became very relevant. With seed money from the government, he constructed two narrow metal staircases proportioned like the 5-floor staircases inside the Fukushima Daiichi reactor buildings. This allowed Yoshida to determine whether his bots could navigate those cramped stairs and tight turns. His acrobatic Quince robots proved themselves able, and after hundreds of tests they received TEPCO’s clearance for field operations. In the summer of 2011, the Quince bots became the first Japanese robots to survey the reactor buildings.
The Quinces were equipped with cameras and dosimeters to identify radioactive hot spots. But the robots struggled with a communication issue: The nuclear plant’s massive steel and concrete structures interfere with wireless communication, so the Quinces had to unspool cables behind them to receive commands and transmit data to their operators. The drawback of that approach soon became apparent. One Quince’s cable got tangled and damaged on the third floor of reactor 2, and the lonely bot is still sitting there to this day, waiting for commands that can’t reach it.
Back at Yoshida’s lab, where modest bunk beds bespeak the dedication of his students, the team is currently working on a new and improved survey bot namedSakura. To guard against future tangles, Sakura not only unspools cable behind, it also automatically takes up the slack when it changes direction. It’s waterproof enough to roll through puddles, and it can carry a heavy camera capable of detecting gamma radiation. The bot can tolerate that radiation: Yoshida’s team tested its electronics (the CPU, microcontrollers, and sensors) and found that they’re radiation-tolerant enough to perform about 100 missions before any component is likely to fail. However, the robot itself becomes too radioactive for workers to handle. Sakura must therefore take care of itself: It recharges its batteries by rolling up to a socket and plugging itself in.
The second step in the Fukushima decommissioning is decontamination, because only when that is complete will workers be able to get inside to tackle more complex tasks. The explosions that shattered several of the reactor structures sprayed radioactive materials throughout the buildings, and the best protective suits for workers in hot zones are of little use against the resulting gamma radiation—a worker would have to be covered from head to toe in lead as thick as the width of a hand.
After the accident, the Japanese government called for robots that could work on decontamination, and several of Japan’s leading companies rose to the challenge. Toshiba and Hitachi have designed robots that use jets of high-pressure water and dry ice to abrade the surfaces of walls and floors; the robots will scour away radioactive materials along with top layers of paint or concrete and vacuum up the resulting sludge. But the robots’ range is defined by their own communication cables, and they can carry only limited amounts of their cleaning agents. Another bot, the Raccoon, has already begun nosing across the floor in reactor building 2, trailing long hoses behind it to supply water and suction.
To clear a path for the robotic janitors, another class of robots has been invented to pick up debris and cut through obstacles. The ASTACO-SoRa, from Hitachi, has two arms that can reach 2.5 meters and lift 150 kilograms each. The tools on the ends of the arms—grippers, cutting blades, and a drill—can be exchanged to suit the task. However, Hitachi’s versatile bot is limited to work on the first floor, as it can’t climb stairs.
Removing spent fuel rods is the third step. Each reactor building holds hundreds of spent fuel assemblies in a pool on its top floor. These unshielded pools, perfectly safe when filled with water, became a focus of public fear during the Fukushima Daiichi accident. After reactor building 4 exploded on 15 March, many experts worried that the blast had damaged the structural integrity of that building’s pool and allowed the water to drain out. The pool was soon determined to be full of water, but not before the chairman of the U.S. Nuclear Regulatory Commission had caused an international panic bydeclaring it dry and dangerous. The reactor 4 pool became one of TEPCO’s urgent decommissioning priorities, not only because it’s a real vulnerability but also because it’s a potent reminder of the accident’s terrifying first days.
The process of emptying that poolbegan in November 2013. TEPCO workers use a newly installed cranelike machine to lower a cask into the pool, then long mechanical arms pack the submerged container with fuel assemblies. The transport cask, fortified with shielding to block the nuclear fuel’s radiation, is lowered to a truck and brought to a common pool in a more intact building. The building 4 pool contains 1533 fuel assemblies, and moving them all to safety is expected to take a year. The same procedure must be performed at the highly radioactive reactors 1, 2, and 3 and the undamaged (and less challenging) reactors 5 and 6.
Containing the radioactive water that flows freely through the site is the fourth step. Every day, about 400 metric tons of groundwater streams into the basements of Fukushima Daiichi’s broken buildings, where it mixes with radioactive cooling water from the leaky reactor vessels. TEPCO treats that water to remove most of its radioactive elements, but it can’t be rendered entirely pure—and as a result local fishermen have protested plans to release it into the sea. To store the accumulating water, TEPCO has installed more than 1000 massive tanks, which themselves must be monitored vigilantly for leaks.
TEPCO hopes to stop the flow of groundwater with a series of pumps and underground walls, including an “ice wall” made of frozen soil. Still, at some point the Japanese public must grapple with a difficult question: Can the stored water ever be released into the sea? Barrett, the former site director of Three Mile Island, has argued publicly that the processed water is safe, as contamination is limited to trace amounts of tritium, a radioactive isotope of hydrogen. Tritium is less dangerous than other radioactive materials because it passes quickly through the body; after it’s diluted in the Pacific, Barrett says, it would pose a negligible threat. “But releasing that water is an emotional issue, and it would be a public relations disaster,” he says. The alternative is to follow the Three Mile Island example and gradually dispose of the water through evaporation, a process that would take many years.
TEPCO must also plug the holes in the reactor vessels that allow radioactive cooling water to flow out. Many of the leaks are thought to be in the suppression chambers, doughnut-shaped structures that ring the containment vessel and typically hold water, which is used to regulate temperature and pressure inside the pressure vessel during normal operations. Shunichi Suzuki, TEPCO’s general manager of R&D for the Fukushima Daiichi decommissioning, explains that one of his priorities is developing technologies to find the leak points in the suppression chambers.
“There are some ideas for a submersible robot,” Suzuki says, “but it will be very difficult for them to find the location of the leaks.” He notes that both the suppression chambers and the rooms that surround them are now filled with water, so there’s no easy way to spot the ruptures; it’s not like finding the hole in a leaky pipe that’s spraying water into the air. Among the robot designs submitted by Hitachi, Mitsubishi, and Toshiba is one bot that would crawl through the turbid water and use an ultrasonic sensor to find the breaches in the suppression chambers’ walls.
If robots prove impractical, TEPCO may take a more heavy-handed approach and start pouring concrete into the suppression chamber or the pipes that lead to it. “If it’s possible to make a seal between the containment vessel and the suppression chamber, then the leaks don’t matter,” Suzuki says. One way or another, TEPCO hopes to have all the leaks stopped up within three years. Sealing the leaks is a necessary precondition for the final and most daunting task.
Removing the three damagednuclear cores is the last big step in the decommissioning. As long as that melted fuel glows inside reactors 1, 2, and 3, Fukushima Daiichi will remain Japan’s ongoing nightmare. Only once the fuel is safely packed up and carted away can the memory begin to fade. But it will be no easy task: TEPCO estimates that removing the three melted cores will take 20 years or more.
First, workers will flood the containment vessels to the top so that the water will shield the radioactive fuel. Then submersible robots will map the slumped fuel assemblies within the pressure vessels; these bots may be created by adapting those used by the petroleum industry to inspect deep-sea oil wells. Next, enormously long drills will go into action. They must be capable of reaching 25 meters down to the bottoms of the pressure vessels and breaking up the metal pooled there. Other machines will lift the debris into radiation-shielded transport casks to be taken away.
Making the task more complicated is the design of the reactors. They have control rods that project through the bottom of the pressure vessels, and the entry point for each of those control rods is a weak spot. Experts believe that most of the fuel in reactor 1, and some in reactors 2 and 3, leaked down through those shafts to pool on the floor of the containment vessel below. To reach that fuel, some 35 meters down, TEPCO workers will have to drill through the steel of the pressure vessel and work around a forest of wires and pipes.
Before TEPCO can even develop the proper fuel-handling tools, Suzuki says, the company must get a better understanding of the properties of the corium—the technical term for the mess of metals left behind after a meltdown. The company can’t just copy the drills that broke up the melted core of the Three Mile Island reactor, says Suzuki. “At Three Mile Island, [the core] remained in the pressure vessel,” he says. “In our case, it goes through the pressure vessel, so it melted stainless steel. So our fuel debris must be harder.” The melted fuel may also have a lavalike consistency, with a hard crust on top but softer materials inside. TEPCO is now working with computer models and is planning to make an actual batch of corium in a laboratory to study its properties.
When the core material is broken up and contained, it will be whisked away to some to-be-determined storage facility. Over the decades its radioactivity will gradually fade, along with the Japanese public’s memory of the accident. It’s a shame that those twisted blobs of corium are too dangerous to be displayed in a museum, where a placard could explain that we human beings are so clever, we’re capable of building machines we can’t control.
Depending on whom you ask, nuclear power stations like Fukushima Daiichi are exemplars of either humanity’s ingenuity or hubris. But, the museum placard might add, these metallic blobs, plucked from the heart of an industrial horror, prove something else—that we humans also have the grit and perseverance to clean up our mistakes.
Molecules manipulate electron spin to increase light emission without the aid of iridium
A new way of coaxing light out of an organic LED may make for cheaper displays and could even provide a way to see magnetic fields.
By choosing a molecule of a particular shape, a team of German and American researchers designed a new type of OLED that has the potential to emit as much light as a commercial OLED, but without the rare metals normally added to make the devices efficient. If manufacturers could leave out metals such as iridium or platinum, they might not have to worry about potential shortages of these elements. This would allow them to bring down the costs of OLEDs, which are increasingly being used in the screens of smartphones and televisions, as well as in solid-state lighting.
OLEDs convert only a fraction of the electrical current they receive into light. That’s because of a quantum mechanical property of the electrons and their positive quasiparticle counterpart holes, called spin. Spin is what gives rise to magnetism; when the spins of a majority of electrons in a material point in the same direction, the material is magnetic. Each electron and each hole can exist in one of two spin states, so when they pair up there are four possible states, three of which dissipate their energy as heat rather than light. This means that only a quarter of the electricity put into the device produces light. OLED makers add metal to the hydrocarbon molecules in their devices to mix up the spin states and increase the number of light-generating combinations.
But it’s also possible for some of the spins to switch to the more light-friendly version on their own, says John Lupton, a physicist at the University of Regensburg, in Germany, who was part of the team that did the work. “You just have to wait long enough for this spin state to spontaneously relax,” he says.
If an electron-hole pair can be held in its electrically excited state long enough for one spin to flip, when it drops to a lower energy state it’ll emit the extra energy as a photon rather than as heat, Lupton explains. “Long enough” is measured in milliseconds, compared with the nanoseconds it usually takes for emission to occur, a difference of six orders of magnitude.
The trick, which the researchers from Regensburg, the University of Bonn, the University of Utah, and MIT explain in a paper published online byAngewandte Chemie, lies in the shape of the organic molecules used in the LED. The researchers developed two kinds of polycyclic aromatic hydrocarbons (carbon-based molecules having multiple ring-shaped components): one called phenazine and the other triphenylene. The atomic structures of the molecules were such that they trapped the charge carriers long enough for the spontaneous change to occur. A peculiarity of the molecule–the researchers speculate that it may have to do with different energy characteristics in different areas of the molecule–prevents the extra energy from being released as heat before the spin can flip. “Because of their shape, you can localize the electron density and therefore the spin density in specific areas in the molecules,” Lupton says, adding that the result was surprising to the researchers, who were actually studying other facets of OLEDs. “If you look at textbooks of physical chemistry, this should not have actually worked,” he says.
Last year another group, led by Chihaya Adachi at Kyushu University, in Japan, demonstrated its own method for making OLEDs without the use of metal. The researchers designed a molecule that relies on fluorescence for light emission, instead of the phosphorescence used in most metal-reliant OLEDs. Their mechanism, called thermally activated delayed fluorescence, takes the heat released by some of the charge carriers and uses it to bump up the energy level of others to the point that they emit light instead of heat when they relax. The Kyushu scientists say their material has an internal efficiency of nearly 100 percent, which translates into about 14 percent of the electricity pumped into the OLED reemerging as light, compared with about 20 percent in commercial OLEDs that use metal.
Alán Aspuru-Guzik, a chemist at Harvard, sees the work by Adachi and Lupton as developments “that could lead to a breakthrough in the field of OLEDs.” The work both groups are doing could lead to better emission in the blue end of the spectrum in particular. Blue organic light emitters have been the most difficult to develop.
At the moment, the price of rare metals needed in OLED manufacturing is so low that manufacturers are unlikely to need either trick soon. And this new method doesn’t actually improve OLED efficiency over what existing devices can deliver, says Lupton. But it could prove appealing to OLED manufacturers if the price of iridium goes up.
Far more interesting may be another aspect of Lupton’s discovery: The spins of the charge carriers in this type of OLED control the wavelength of the light emitted. “You can actually measure the spin of the electron within your OLED by using the color,” Lupton says. And because spin on the quantum level translates into magnetism in the macro world, “if you design this in the right way you could make it incredibly sensitive to magnetic fields,” Lupton says. “That will actually allow us to use the color of the OLED as a compass.” He says such a device could be more sensitive than Hall effect devices, which are common in smartphone navigation systems and in automobiles, where they measure the rotation of the wheels.
The research might even provide a new clue to how birds navigate using Earth’s magnetic field. While the exact mechanism is still debated, some scientists suspect that their eyes let them see shifts in the field as subtle variations of color. Lupton says they may be sensitive to color changes caused by alterations in the spins of electrons.
On Christmas night, Maja Bendtsen and her husband were curled up on the couch watching TV in their cozy house on the Danish island of Bornholm. Suddenly the house lost power. “The lights flickered briefly and then everything went black,” Bendtsen recalls.
Peeking out the window, they saw that the whole neighborhood was dark. A few quick phone calls confirmed that all of Bornholm was without power. Bendtsen, an engineer with the island’s utility, Østkraft Net, mentally ruled out the obvious culprits: It wasn’t a particularly busy night, as Christmas festivities had wrapped up with the midday meal, nor was the weather particularly cold or stormy.
Incredibly, this was the fourth such mishap in 10 years. “We’re getting accustomed to it, almost,” Bendtsen says. By “accustomed” she doesn’t mean “resigned.” During the last decade, Østkraft has built up an impressive array of renewable sources [PDF] like wind, solar, and biomass, which can now supply about three-quarters of the island’s demand. In the process, Bornholm has transformed itself into a kind of living laboratory for testing new energy ideas.
Now it is taking the ultimate step, by deploying one of the world’s most advanced smart grids, called the EcoGrid EU. It’s a four-year, €21 million (US $27 million) project, funded in part by the European Union, that aims to demonstrate how electricity will be produced, distributed, and consumed in the future. While any smart grid today can track in excruciating detail electricity supply, demand, and other information, Bornholm’s is one of the first in which individual household consumption can respond to real-time price changes in the electricity market. By doing that, the grid’s customers are helping to balance the sometimes big and sudden swings in supply that inevitably accompany the use of wind and solar power.
And as Bornholm goes, so goes Denmark and the rest of Europe. TheEuropean Commission’s 20/20/20 Plan, for instance, states that by the year 2020, greenhouse gas emissions will be cut by 20 percent, while renewable energy usage and energy efficiency will both rise by 20 percent. Last year, theDanish parliament approved an even more ambitious target: to have renewables supply 35 percent of the country’s total energy needs—not just electricity but also heating and transportation—by 2020, and an incredible 100 percent by 2050. Can those targets actually be reached?
That’s what the EcoGrid project aims to find out. The choice of Bornholm, with its 41 000 full-time residents, to host it was no accident. Although the island’s beauty draws hundreds of thousands of tourists every year, it’s not just a vacation destination. Commercial fishing, dairy farming, and arts and crafts all buttress the economy and give Østkraft a representative mixture of commercial, industrial, and residential customers, as well as schools, a hospital, an airport, and an international seaport.
“We’re like a microcosm of Danish society,” Bendtsen says. “We are in many senses a picture of the future power system in Denmark.” And by studying how a high-tech grid can help this little island cope with the challenges of renewable energy, EcoGrid’s organizers hope to discover larger lessons for the wider world.
Bornholm has long held a special place in the Danish psyche. According to local legend, when God got to the end of his creation he still had bits of paradise left over, and so he threw them all down in the Baltic Sea and created Bornholm. In medieval times, another tale goes, Danish kings hid their mistresses away in the island’s large forest. Today, Europeans flock to Bornholm in the summer for its beautiful sandy beaches, sunny (for Denmark) weather, and, yes, that forest.
For Jacob Østergaard, though, the most attractive thing about Bornholm isn’t the beaches or the sun: It’s that pesky undersea cable, or, more important, what that cable allows him as a power engineer to do. Østergaard, a professor of electrical engineering at the Technical University of Denmark (DTU), in Lyngby, is involved in a number of electricity projects on Bornholm, including EcoGrid. The cable can be switched off at will, he explains, putting the Bornholm grid into what’s known in electricity circles as “island” mode. And that’s interesting, he says, because the wealth of wind power makes the Bornholm grid challenging to operate and fascinating to study. Last year, he and his colleagues even built a duplicate of the Østkraft control room on the DTU campus to monitor the Bornholm grid in real time.
On a windy day, Bornholm’s turbines can supply up to 30 MW of power, or more than half of the island’s peak load of 55 MW. But the wind blows as it will, and that variability and unpredictability can wreak havoc on the grid’s stability. If the wind abruptly dies, for instance, electricity supply could dip way below demand, causing the grid’s nominal 50-hertz frequency to likewise plummet. A dip or a spike of just over a tenth of a hertz is cause for alarm, Østergaard says, and if it drifts out of kilter even further—to, say, 47 Hz—it can trigger a blackout.
Something close to that happened on 17 September 2009 [PDF], when the sea cable was shut down for maintenance. To keep the grid balanced, the wind turbines were also initially shut down. At 11:25 a.m., all was calm, with the grid frequency steadily hovering just north of 50 Hz. Then, at 11:26 a.m., six of the turbines were turned on, and over the next several minutes their share of the island’s power supply rose to 15 percent.
But as the wind output grew erratic, so did the grid frequency, spiking more than a tenth of a hertz several times and dropping sharply to 49.8 Hz just before noon. Østkraft engineers and DTU researchers were closely monitoring the situation and quickly stepped in, ramping up the output of the island’s conventional generators and dialing back the proportion of wind to 10 percent, at which point the frequency returned to normal.
Dozens of experiments before and since have confirmed that there’s an upper limit of about 15 percent on the amount of wind power that Bornholm’s grid can absorb when in island mode. And to greater or lesser degrees, all power grids that have a substantial amount of wind and solar do the same thing,falling back on traditional “peak” generators to compensate for gaps in renewable output. Some grid operators also store electricity in pumped hydroor compressed-air installations or in industrial-grade batteries, but the latter aren’t yet economical, and the former can be used only in certain locations.
But what if, instead of boosting generation when demand is high, you just cut back demand? Answering that basic question is at the heart of the EcoGrid.
The goal of the smart grid isn’t to demonstrate that Bornholm can be energy independent, notes Bendtsen, sitting in one of the light-filled offices at Østkraft’s sleek headquarters just outside the main town of Rønne. The island is independent already: At present it has about 50 MW of domestic capacity, from a mix of conventional coal and diesel generators, three dozen wind turbines that dot the countryside like giant pinwheels, rooftop photovoltaics, a biogas plant, and several wood-chip- and straw-fired plants. As a result, the Christmas night blackout lasted only a few hours, the time it took to bring the domestic plants online.
But producing electricity that way is expensive, and so the cable to Sweden lets the island buy electricity from the Nordic grid when it’s cheap and sell when the price is high. Ordinarily, trading in electricity markets is done at the level of utilities and the like. EcoGrid is letting individual households and smaller businesses also become market players.
The idea is to shift the consumption of electricity to periods of the day and night when electricity demand and prices are low, Bendtsen explains. You could do that by simply sending people a text message whenever prices change. But that would quickly get tiresome.
“And if we let people interact directly with the market, their behavior will, of course, change,” says Østergaard. “Everyone will want to charge their electric vehicles when the price is low, for example. If too many people do that, you create congestion in the weakest parts of the grid.”
Instead, EcoGrid’s people have installed smart grid controllers [PDF] in about 1200 households and a hundred businesses, and since April the controllers have been receiving a continuous stream of data based on the 5-minute price for electricity in theNordic electricity market, which covers Denmark, Finland, Norway, and Sweden. The controllers wirelessly communicate with designated appliances, and algorithms determine whether to turn each one on or off, based on factors like the time of day, the weather, and current, past, and future market prices.
At first, the project’s organizers envisioned regulating a whole suite of household machines—dishwashers, washing machines, refrigerators, TVs, lights. It turns out, though, that although such smart appliances have been on the market for years, there’s still no standard protocol for automating them. So your dishwasher might speak ZigBee while your freezer converses in KNX, and they can’t easily understand each other.
Standards clearly would help, says Bendtsen. “Imagine that you go to a white goods store to buy a new dishwasher,” she says. “You have to consider not just what size and what color and how much energy and water does it use but which language does it speak. Fine if you’re an engineer, but we need some sort of standard so that ordinary people don’t have to think about all these things themselves.”
In the meantime, the EcoGrid is keeping things simple and dealing primarily with households that have electric heating systems and heat pumps. In 700 of those households, the heating system is directly controlled using algorithms developed at IBM’s research lab in Zurich. A thermal model of each household has been created, based on factors like electricity usage patterns and the size of the windows and walls, explains Dieter Gantenbein, smart grid project leader at IBM Research–Zurich.
“If you leave the window open a lot to let your cat in and out, then your parameters will be different from somebody who keeps the windows closed,” he says. From the thermal model, he adds, “we can determine the electrical flexibility of this house—we have a planned strategy on how to throttle the heat pump up or down. The goal is that the owners do not see any reduction in their quality of life.” About 100 businesses on Bornholm are being similarly equipped.
Another 500 or so households are being treated as a single electricity- consuming unit; Siemens’s Denmark subsidiary is coordinating that part of the smart grid. The remainder of the 1900 households enrolled in the project—about a tenth of the island—are just getting smart meters, which provide them with fine-grained information about their electricity consumption and market prices but don’t control their usage in any way.
Interestingly, EcoGrid participants aren’t being told to expect a drop in their electricity bills. That’s partly a way to manage expectations, but it’s also just being realistic: Numerous studies in Denmark and other countries have shown that the incremental savings people get from being more energy efficient usually aren’t enough to change their behavior. That said, Gantenbein notes, there’s been no lack of volunteers on Bornholm.
“Danes take preservation of the environment close to their hearts,” he says. “It’s like a sport. They heat carefully, they close doors, they use different technologies, and by being engaged, they are very enthusiastic to participate in such an ambitious pilot.”
Martin Kok-Hansen is just such an enthusiast. He and his family live in a one-story brick house on the northern edge of Rønne, and he was among the first on Bornholm to sign up for the smart grid. The real estate agent says he decided to participate for the same reason he traded in his Jeep Grand Cherokee for a Volkswagen Golf a few years back. “In the future, we won’t have that much power,” he says. “And my son is probably going to have kids as well. Where are they going to get all the power from?”
There’s now a Landis+Gyr smart meter on the wall of Kok-Hansen’s garage, a small relay and reader in the laundry room that turns the electric heater on and off, and a digital thermostat in the living room; all three of these units communicate wirelessly with a “gateway” controller and router that in turn connect via the Internet to the utility company. The gateway and most of the other hardware, as well as the household communication and end-user Web services, were designed by a company called GreenWave Reality, based in Irvine, Calif.
Like other participants, Kok-Hansen can set limits on how warm or cool his house gets. “If it’s 21 °C in here and they need the power, they can switch off the heat and let it fall to 18 °C,” he says. That’s two or three degrees cooler than normal, but he thinks he can cope. “Maybe you put on a sweater for a while.”
Standing in his recently remodeled kitchen, laptop perched on the black granite countertop, he logs into his account on the Østkraft website. He can see, in near real time, how much electricity he’s using. It’s been illuminating, to say the least.
“Right now I’m using 1200 watts,” he says, pointing to a graph onscreen. “But when you turn this one on”—he walks over to a wall switch and flicks on the recessed halo gen lights overhead—“you see that the usage goes way up.” Sure enough, within a few seconds, the graphed value nearly doubles. That’s because each halogen bulb is 50 watts, and the kitchen has 16 of them. At current rates, 1 kilowatt-hour runs about 2 Danish kroner, or 35 cents. So keeping those lights on just 4 hours a day is costing him $500 a year, he figures. He plans to swap them out soon for compact fluorescents or LEDs.
“I definitely will change those,” he says. “This is a whole new lifestyle.”
The SuperBest supermarket just off the main square in Rønne is packed on a Saturday afternoon. A young man stops at a refrigerator, pulls out a few bottles of beer, and puts them in his cart. He doesn’t bother to read the explanatory sticker plastered across the refrigerator’s glass front, nor does he glance up at the shoebox-size device sitting atop the cooler. And so he may have no inkling that this refrigerator, and about 200 other units like it on Bornholm, is special: Like the EcoGrid’s heat pumps, the bottle coolers are helping to balance the grid [PDF].
Two years ago, researchers at DTU modified each cooler so that it directly monitors grid frequency, explains Østergaard. In a series of experiments, his group has shown that the coolers can be programmed to turn themselves off when the frequency drops by more than a tenth, and then automatically turn back on when the frequency stabilizes. “If it’s just a small frequency variation, then you just have a small number of coolers respond,” he explains. “But if there’s a large variation, then all of them will react.”
The concept of using coolers, pumps, and other appliances in this way has been kicking around for a while, Østergaard says, but only in the last decade or so has it become economically feasible. “These days, every cooler has a thermostat with a microcontroller and processor, so you can just program it to do this,” he notes. Whereas the heating systems hooked up to the EcoGrid are reacting to market prices, which are an indirect measure of power supply and demand, the Bornholm bottle coolers are detecting conditions on the grid itself.
Østergaard says both approaches are useful: “It’s important to balance the grid on all time scales, from seconds and minutes to days and years.” And by using information technology to strategically roll back demand, rather than ramping up supply, the smart grid can create a more efficient network. “Moving bits and bytes is less expensive than moving amperes,” he says.
As to whether Denmark and the rest of Europe will meet their lofty energy goals, Østergaard’s not saying. “It’s good to have goals,” he allows. “I don’t know if we will succeed. But without projects like this, there is no chance at all.”
As part of the IEEE Best fresher competition, IEEE CS CET conducted “CodeStreak”, a C/C++ coding event. The aim of the event was to identify the best incoming student in coding in order to encourage them to improve their coding skills in the future and to make them a part of the core technical team in the college, right from the start.
A written preliminary test was conducted of which 6 finalists were chosen. The finalists were given problems that involved lateral thinking and had applications to the real-world. All the finalists performed brilliantly and most of them solved all the problems within the stipulated time. The winners were chosen by judging on the efficiency of the code, output obtained, optimizations done and documentation of the code.
The winners of the event were: Revathy (CS) and Aswin PJ (EC).