Posts Tagged ‘solar panels’
13-Year-Old Designs Super-Efficient Solar Array Based on the Fibonacci Sequence
On a bleak winter hiking trip to the Catskill Mountains, the 7th-grader from New York noticed a pattern among tree branches, and determined (as naturalist Charles Bonnet did in 1754) that the pattern represented the Fibonacci sequence of numbers. Aidan wondered why, and figured it had something to do with photosynthesis.
In a pretty innovative experiment, this set about duplicating an oak tree, comparing its sunlight-capturing abilities to a traditional rooftop solar panel array. Guess what he found?
First he determined the ratios representing the spiral pattern of the leaves and branches on an oak tree, using a cylindrical double-protractor tool of his own design. Then he copied the pattern using a computer program, and built an oak tree-shaped solar array out of PVC pipe. He next built a flat-panel array mounted at 45 degrees, like a typical home rooftop array, and attached data loggers to each model to monitor voltage.
You can read Aidan’s award-winning , which walks you through his experiment design and his results. But the short story is that his tree design generated much more electricity — especially during the winter solstice, when the sun is at its lowest point in the sky. At that point, the tree design generated 50 percent more power, without any adjustments to its declination angle.
He determined the tree’s Fibonacci pattern allowed some solar panels to collect sunlight even if others were in shade, and prevented branches on a tree from shading other branches.
Now Aidan is studying other tree species and improving his PVC model to determine how it could be used to make more efficient solar arrays. He’s applied for a patent, too. Aidan’s design won him a 2011 Young Naturalist Award from the American Museum of Natural History. Not to mention the admiration of anyone who has tried to get a kid to appreciate nature.
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Mausoleum-Mounted Solar Panels Light Up A Spanish Town
Santa Coloma is thus far the only town to use alternative power from its cemetery to fill some of the energy needs of its 120,000 residents; the 100 kilowatts is enough to power 60 households. In April, officials from the U.S. Department of Veterans Affairs installed a wind turbine at the Massachusetts National Cemetery, but it will provide power only for the cemetery.
Video: Solar Panels Can Be 3-D Printed Onto Regular Paper, Folded 1,000 Times
The cell is tough enough to work even after being folded into a paper airplane — unlike many "flexible" cells, it's not merely bendable, but foldable as well. It’s made using a relatively simple vapor deposition process, rather than the typical high-temperature etching process used to make solar cells.
Like the we saw earlier this month, the system uses a 3-D printing technique to deposit materials onto a surface. The process is a little more complex than using a printer, however, because it requires five layers of material and a stencil to form the patterns of the cells. It also has to be done in a vacuum chamber, so it’s probably not doable for the average DIY-er.
But as points out, the vapor deposition process is widely used throughout various industries — it’s similar to the process used to make the silver lining in bags of potato chips — so it can be done on a large scale at low cost.
To test their technology, engineers led by chemical engineering professor Karen Gleason folded a paper photovoltaic cell into a paper airplane, and the cell still collected energy from sunlight. They also printed one on a piece of plastic, like the kind used to make soda bottles, and folded that one 1,000 times. It still worked, while a traditionally-produced cell on the same plastic failed after just one fold.
The team even printed a cell on a piece of paper, and then put that paper in a regular laser printer to see what would happen. It still worked, even after a laser-heated layer of toner ink was printed on top of it. In tests, the folded cells were still able to gather ambient sunlight to power a clock and other devices.
They are not that efficient — a paltry 1 percent — but the researchers think that will improve as they fine-tune the “ink” and the deposition process. But even now, “it’s good enough to power a small electric gizmo,” said engineering professor Vladimir Bulović. Watch a demonstration below.
Foldability is important for portable, cheap circuits — a circuit or PV cell that can withstand being crumpled in a pocket would be a major advancement for portable devices. But the lightweight nature of this cell may be its biggest breakthrough. Functional photovoltaic cells printed on paper or thin plastic could have a host of uses, from lightweight battery technology to portable power for developing countries.
The research is reported in this week’s issue of the journal Advanced Materials.
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New Jerseyites Hate New Solar Panels, Brand Them "Hideous"
New Jersey has a robust alternative energy plan that aims to secure 23 percent of its electricity from renewable sources within ten years--an ambitious goal that'll be all the more difficult to achieve if suburbanites protest the installation of solar panels on their streets. At the moment, there are talks in some towns about the efficiency of the current setup compared with how much the residents are annoyed by them--some say the panels interfere with emergency call boxes, or that spreading out the panels in this way somehow impedes efficiency (that part's not true, according to solar experts). But it looks like New Jersey's solar plans aren't in any serious danger: The resistance is only in certain small pockets of the state, and the utility owns the electric poles anyway, so there's not much those angry suburbanites can do. Maybe they'd prefer some instead?
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MIT Researchers Use Viruses To Build More Efficient Solar Panels
Scientists already knew that carbon nanotubes, rolled-up sheets of graphene, could improve the efficiency of photovoltaic cells. Ideally, the nanotubes would gather more electrons that are kicked up from the surface of a PV cell, allowing a greater number of electrons to be used to produce a current.
But there are complications — carbon nanotubes come in two varieties, functioning either as semiconductors or wires, and they each behave differently. They also tend to clump together, which makes them less effective at gathering up their own electrons. MIT researchers found that a certain bacteria-attacking virus called M13 can be used to make things go more smoothly.
M13 has peptides that bind to the carbon nanotubes, keeping them in place, . Each virus can grip about five to 10 nanotubes each, using roughly 300 of the protein molecules. The viruses were also genetically engineered to produce a layer of titanium dioxide, which happens to be the key ingredient in Grätzel cells, a.k.a. dye-sensitized solar cells. (These cells use TiO2 instead of silicon, and their inventor, Michael Grätzel of the École Polytechnique Fédérale de Lausanne, won the for them last year.) This close contact between TiO2 nanoparticles helps transport the electrons more efficiently.
The viruses also make the nanotubes water-soluble, which could make them easier to incorporate into PV cells at room temperature, lowering manufacturing costs.
Graduate students Xiangnan Dang and Hyunjung Yi, MIT professor Angela Belcher and colleagues tested this method with Grätzel cells, but they say the technique could be used to build other virus-augmented solar cells, including quantum-dot and organic solar cells.
They also learned that the two flavors of nanotubes have different effects on solar cell efficiency — something that had not been demonstrated before. Semiconducting nanotubes can enhance solar cells’ performance, but the continuously conducting wires had the opposite effect. This knowledge could be useful for designing more efficient nanoscale batteries, piezoelectrics or other power-related materials.
The virus-built structures enhanced the solar cells’ power conversion efficiency to 10.6 percent from 8 percent, according to MIT News. That’s about a one-third improvement, using a viral system that makes up just 0.1 percent of the cells’ weight.
“A little biology goes a long way,” Belcher said in an MIT News article. The researchers think with further research, they can improve the efficiency even more.
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Attractive Italian Viaduct Has Wind Turbines Built In
The concept would use the space between an existing viaduct in southern Italy to install 26 wind turbines, which designers Francesco Colarossi, Giovanna Saracino and Luisa Saracino say could provide 36 million kilowatt hours of electricity every year.
The design team conceived the Solar Wind project for a contest that aims to repurpose some old, unused viaducts near Calabria, a region in the toe of Italy. It would cost about $55 million to demolish the viaducts, so town officials for proposals that would re-use them in an environmentally friendly way. The wind turbine bridge took second place.
The proposal also includes a solar-paneled roadway to provide another 11.2 million kilowatt hours, Colarossi and colleagues say. It turns the entire viaduct into a park, with spaces to pull over and take in the view off the Italian coast. Travelers could stop and buy fresh produce grown in solar-powered greenhouses located along the bridge. The whole roadway would be covered in a dense grid of solar cells coated in a thin, transparent plastic, the designers say.
All in all, the system would be capable of generating 40 million kWh each year, enough to power 15,000 homes.
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Marines in Afghanistan Find That Solar Panels Save Soldiers’ Lives
The Marines and sailors of 3rd Battalion, 5th Marine Regiment arrived last October at Forward Operating Base Jackson, outside Sangin, Afghanistan, with an array of solar equipment. The battalion’s generators typically use more than 20 gallons of fuel a day, but the Marines have cut that to 2.5 gallons a day, according to Staff Sgt. David Doty, who maintains the gear.
Saving generator fuel can cut down on the number of convoys the Marines must make to fueling stations, and therefore lessen the chances of becoming a target. The 3/5, based at Camp Pendleton, Calif., lost more than a dozen Marines right after deployment last fall, including nine men killed by IEDs over a four-day period in October.
“A refueling vehicle becomes a screaming [easy] target,” said 1st Lt. Daric Kleppe, commander of 1st Platoon, India Company.
The solar array is called an Experimental Forward Operating Base, ExFOB, and involves several different solar panels for a variety of uses, according to a news report by the Marines. The Solar Portable Alternative Communication Energy System, or “SPACES,” is a small, portable solar panel that can be used to power small items like a radio. There's also a PowerShade, a large solar tarp that fits over a Marine’s tent to power his lighting system, and the Ground Renewable Expeditionary Energy System, or “GREENS,” which can power four computers at a time, enough for a whole platoon’s command center. The ZeroBase Regenerator, seen in the above photo, is a six-paneled array that funnels energy into a single battery, powering more than 20 lighting systems and 15 computers throughout the night.
The setup has plenty of obvious benefits — for instance, during long patrols in Helmand province, the Marines can use their solar tarps to recharge their radio batteries, leaving more room to pack ammunition.
Sangin, located in southwestern Afghanistan, is one of the country’s , with a strong presence from the Taliban and opium traders. American armed forces replaced British troops in the region in September.
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