Posts tagged with "Wind Turbines":

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Could evaporating water be the newest renewable energy source? Columbia researchers harnesses the power of bacterial spores

A biophysicist at Columbia University has discovered how to tap evaporating water as an electrical energy source using a simple device made from bacterial spores, glue, and LEGO bricks. Ozgur Sahin’s findings operate at the cellular level, based around his research on the Bacillus bacteria, a microorganism commonly found in soil—and its implications could potentially be far reaching. In high humidity, the spores absorb moisture from the air, expanding up to 40 percent in volume. In dry conditions, the reverse occurs. “Changing size this much is highly unusual for a material that is as rigid as wood or plastic, said Sahin, associate professor of Biological Sciences and Physics at Columbia University. “We figured that expanding and contracting spores can act like a muscle, pushing and pulling other objects. We noticed that we could harness the motion of spores and convert it to electrical energy.” Sahin’s prototype generator is modeled after a wind turbine, which captures kinetic energy and converts it into electricity. Attached to the generator is a flexible, elastic rubber sheet coated in a thin layer of spores. Using a fan and a small container of water, Sahin’s team showed that dry laboratory air and the evaporating moisture from the surface of the water can cause the entire sheet to curl up and straighten, rotating the turbine back and forth to yield electricity. “The biggest form of energy transfer in nature is evaporation. Our climate is powered by evaporating water from oceans and we have no direct way of accessing this energy,” Sahin pointed out. In a paper published in Nature Nanotechnology earlier this year, Sahin and his team, ExtremeBio, consisting of collaborators from Harvard University and the Loyola University Medical Center, showed that these spores produced a thousand times more force than human muscles, and that even a little moisture from evaporation could trigger movement strong enough to be harvested. “The subtle phenomenon of evaporation has big potential. This may be an opening for a completely new energy platform,” said Sahin, whose findings also bode the possibility of developing environmentally benign batteries and engineering stronger materials that mimic muscular movement in robots and prosthetic devices. Pound for pound, the spores pack more energy than other materials used in engineering for moving objects, according to Sahin’s paper. The ramifications are simply enormous in terms of energy savings for the construction and other industries, as well as possibly circumventing the depletion of fossil fuels. In an online issue of Nature Communications, Columbia University scientists reported the development of two novel devices powered entirely by evaporation – a floating, piston-driven engine dubbed the Moisture Mill, which generates electricity and causes a light to flash, and a rotary engine that drives a miniature car. Both devices contain a thin layer of spores. When the evaporation energy is scaled up, researchers predict that it could one day produce electricity from giant floating generators on bays or reservoirs, or from huge rotating machines like wind turbines that sit above water.
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Electricity-generating Wind Trees will power Paris’ Place de la Concorde

The power grid of the future may consist entirely of trees—and we don’t mean biofuel. French R&D company New Wind recently pioneered the “wind tree,” a wind turbine that is both silent and soothing to behold. While wind turbines are ordinarily thought to be noisy and unsightly, the “Arbre à vent” developed by French entrepreneur Jerôme Michaud-Larivière resembles modern art’s sculptural interpretation of a tree. The biomorphically-inspired contraption features 72 electricity-generating leaves oriented vertically along a white steel frame approximating tree branches.   Made of lightweight plastic treated with element-resistant resin, the leaves can harness winds as light as 4.4 miles per hour, enabling the turbine to continue generating power for 280 days per year, factoring in climate vacillations. Despite this keen sensitivity, the turbine is designed to withstand Category 3 gusts (wind speeds of up to 129 miles per hour). At 26-by-36 feet the “wind tree” is no taller than the average tree, and camouflages with the landscape instead of being a looming presence. Each rotating leaf contains a generator with a capacity of 3.1 kilowatts of electricity—a modest amount, but a streetscape lined with wind trees could rack up enough juice to power all nearby street lights or a small apartment, according to EarthTechling. The circuitry is wired in parallel and each generator is sealed in protective casing so that the breakdown of one leaf does not gum the system. Meanwhile, the company is replicating the plant-inspired design template in a scaled-down "wind bush" currently in the works and "foliage" as a  wind power catch-all on rooftops and balconies and along roadsides to power variable-message signs. From May through the following March, a demonstrator tree will be installed at the Place de la Concorde in Paris, a major public square, to introduce it to the general public, after which 40 more wind trees will be installed around the country. While prototypes have been installed on select private properties, the item will not be mass produced until summer 2016, and even then will be available only in France and nearby European countries. Each wind tree is slated to retail for approximately $36,500 apiece—slightly more expensive than the traditional 10-kilowatt turbine, which costs an average of $30,000 including installation.
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Testing Begins on Renzo Piano’s Dragonfly Wind Turbine Blade

You might know Renzo Piano as the architect behind many of the world's leading museums, but get ready to meet Renzo Piano, wind-turbine expert. Testing has commenced on Renzo Piano’s small-scale wind-turbine blade at the Molinetto Test Field near Pisa, Italy. Piano’s turbine blade resembles a dragonfly’s wing and incorporates elements from the insect that promote stability in flight in order to allow the turbine to tolerate gale-force winds. Piano's slender, two-blade turbine differs from the customary three-blade scheme and has proven to operate successfully in low-intensity wind. To avoid spinning too quickly during storms, larger turbines typically use particular blades that stall at too-high speeds, or computerized systems that regulate the blade angles according to wind speed. Such systems are too costly to use with small-scale turbines, as they do not generate enough power to justify the price. The dragonfly turbine, which benefits from tough, lightweight composite resources, takes advantage of even the slightest breeze—it utilizes winds of only 6.5-feet-per-second for rather endless power. It can also be used effectively even at lower elevations than its larger counterparts. Designed with transparent plexiglass panels that emphasize the internal carbon structure, the turbine has minimal visual impact. While not in motion, the blades align with the mast to blend in with the environment. Held to the ground by cables, the tower is just 65 feet tall and 13 inches in diameter. The dragonfly has generated over 1200 KWh of energy over the course of a couple months. The prototype will continue to be tested for a few more months, followed by mass production as part of a groundbreaking approach that aims for advanced performance on all renewable technologies.