SolarPrint Develops Ready-To-Print Solar Cells

by Timon Singh

 

Irish company SolarPrint has developed a new type of printable solar cells that can be produced quickly and easily and can even generate energy from fading sunlight. Since the dye-sensitized cells use less raw materials than traditional solar cells, costs can be kept down, and it is hoped that the simple-to-produce solar cells will transform how the world uses energy.

Speaking to GreenTechMedia, SolarPrint co-founder and CEO Mazhar Bari said, “When you are travelling around the world you suddenly realize, ‘Where are the bloody solar panels?’” With that in mind Bari, an Irish citizen with Pakistani roots and a physics degree from Cambridge, sent out to explore dye sensitized solar cell (DSSC) technology, that is “part printable, part liquid.”
SolarPrint effectively has eliminated the liquid part of DSSC and replaced it with nanomaterials, so that all of the active elements of SolarPrint’s cells can be applied in the printing process. The SolarPrint cells are also more efficient because they are based on a rounded nanotech structure instead of the traditional angular crystalline structure of silicon materials. Electrons have to hit the crystalline structures “at the right angle” to generate electricity, however in nanostructure cells a curved surface makes the angle of absorption much larger.
“There are many components in the cell. One layer is called the electrolyte layer.” As a liquid, that layer is “terrible,” Bari said, who is not one to mince his words. The efficiencies are adequate, he said, but “lab time is crap and it cannibalizes the materials in the cell.” The SolarPrint process replaces that liquid with a printable electrolyte paste made of smart nanomaterials, carbon nanotubes, graphene and ionic salts. “And it’s a fully printable device.”
However there is a drawback with the mass manufacturing of dye-sensitized solar cells. More and more consumers demand reliability from solar cells, with lifespans of up to 30 years, so there is concern when the cells can be produced cheaply and easily, especially as many seem to break down in due course.
However Bari believes that SolarPrint’s ability to capture low and overcast light levels both indoors and outside will give his company an edge in the market. “Dye solar cells work very well indoors,” Bari said. “The voltage doesn’t drop like crazy (like silicon) and it is able to produce reasonable power in indoor light — four or five times higher than silicon.” “One day, the whole world will be covered in dye solar cells. That’s our vision,” said B

PHATport Solar Awning Provides Outdoor Shade and Solar Power

   by Diane Pham

PHAT Energy recently unveiled the PHATport 350, an outdoor solar structure that can serve as everything from a cozy, sun-sheltering patio to an energy-generating car port (imagine plugging your EV into one of these!). The self-contained solar shade will be on display at this year’s Solar Power International in Los Angeles(which runs today and tomorrow!), and the company has rolled out a quirky ad campaign that features a series of solar power fables sure to Flip Your Switch. Check out their hilarious videos after the jump! 

We couldn’t think of a better place for a solar awning than perpetually sunny Los Angeles. The videos depict a mythical mermaid who, upon observing the misery of various people in their drab backyards, conjures up the solar gods to bring them a PHATport. The campaign was created to bring a jolt of excitement to the drab world of solar marketing.

As the reps of PHAT Energy state, “This is a fun campaign about a product that needs to be de-mystified. Let’s get away from product performance specs and have fun with the life benefits. So we show people kissing, dancing, and celebrating after being touched by solar energy. We have a beautiful spiritual mermaid who alters bad situations that are allegories for confusion, pollution and apathy. It seems completely appropriate to celebrate this fantastic technology with natural and common human emotions of celebration, especially when they occur under a PHATport.”

 My first cousin, Michael Lidell, sent me a link to this fascinating article that appeared in The Atlantic magazine. It is incredible what the human mind will come up with ... and I'm not speaking of the Super Soaker squirt gun.

 

What Lonnie Johnson is on to is a perpetual motion/energy device that only needs solar heat to function. This could be incredible. A good article!

 

Shooting for the Sun

From his childhood in segregated Mobile, Alabama, to his run-ins with a nay-saying scientific establishment, the engineer Lonnie Johnson has never paid much heed to those who told him what he could and couldn’t accomplish. Best known for creating the state-of-the-art Super Soaker squirt gun, Johnson believes he now holds the key to affordable solar power.

By Logan Ward

IMAGE CREDIT: BEN BAKER/REDUX

IN MARCH 2003, the independent inventor Lonnie Johnson faced a roomful of high-level military scientists at the Office of Naval Research in Arlington, Virginia. Johnson had traveled there from his home in Atlanta, seeking research funding for an advanced heat engine he calls the Johnson Thermoelectric Energy Converter, or JTEC (pronounced “jay-tek”). At the time, the JTEC was only a set of mathematical equations and the beginnings of a prototype, but Johnson had made the tantalizing claim that his device would be able to turn solar heat into electricity with twice the efficiency of a photovoltaic cell, and the Office of Naval Research wanted to hear more.

Projected onto the wall was a PowerPoint collage summing up some highlights of Johnson’s career: risk assessment he’d done for the space shuttle Atlantis; work on the nuclear power source for NASA’s Galileo spacecraft; engineering help on the tests that led to the first flight of the B-2 stealth bomber; the development of an energy-dense ceramic battery; and the invention of a remarkable, game-changing weapon that had made him millions of dollars—a weapon that at least one of the men in the room, the father of two small children, recognized immediately as the Super Soaker squirt gun.
Mild-mannered and bespectacled, Johnson opened his presentation by describing the idea behind the JTEC. The device, he explained, would split hydrogen atoms into protons and electrons, and in so doing would convert heat into electricity. Most radically, it would do so without the help of any moving parts. Johnson planned to tell his audience that the JTEC could produce electricity so efficiently that it might make solar power competitive with coal, and perhaps at last fulfill the promise of renewable solar energy. But before he reached that part of his presentation, Richard Carlin, then the head of the Office of Naval Research’s mechanics and energy conversion division, rose from his chair and dismissed Johnson’s brainchild outright. The whole premise for the device relied on a concept that had proven impractical, Carlin claimed, citing a 1981 report co-written by his mentor, the highly regarded electrochemist Robert Osteryoung. Go read the Osteryoung report, Carlin said, and you will see.
End of meeting.
Concerned about what he might have missed in the literature, Johnson returned home and read the inch-thick report, concluding that it addressed an approach quite different from his own. Carlin, it seems, had rejected the concept before fully comprehending it. (When I reached Carlin by phone recently, he said he did not remember the meeting, but he is familiar with the JTEC concept and now thinks that the “principles are fine.”) Nor was Carlin alone at the time. Wherever Johnson pitched the JTEC, the reaction seemed to be the same: no engine could convert heat to electricity at such high efficiency rates without the use of moving parts.
Johnson believed otherwise. He felt that what had doomed his presentation to the Office of Naval Research—and others as well—was a collective failure of imagination. It didn’t help that he was best known as a toy inventor, nor that he was working outside the usual channels of the scientific establishment. Johnson was stuck in a Catch-22: to prove his idea would work, he needed a more robust prototype, one able to withstand the extreme heat of concentrated sunlight. But he couldn’t build such a prototype without research funding. What he needed was a new pitch. Instead of presenting the JTEC as an engine, he would frame it as a high-temperature hydrogen fuel cell, a device that produces electricity chemically rather than mechanically, by stripping hydrogen atoms of their electrons. The description was only partially apt: though both devices use similar components, fuel cells require a constant supply of hydrogen; the JTEC, by contrast, contains a fixed amount of hydrogen sealed in a chamber, and needs only heat to operate. Still, in the fuel-cell context, the device’s lack of moving parts would no longer be a conceptual stumbling block.
Indeed, Johnson had begun trying out this new pitch two months before his naval presentation, in a written proposal he submitted to the Air Force Research Laboratory’s peer-review panel. The reaction, when it came that May, couldn’t have been more different. “Funded just like that,” he told me, snapping his fingers, “because they understood fuel cells—the technology, the references, the literature. The others couldn’t get past this new engine concept.” The Air Force gave Johnson $100,000 for membrane research, and in August 2003 sent a program manager to Johnson’s Atlanta laboratory. “We make a presentation about the JTEC, and he says”—here Johnson, who is black, puts on a Bill-Cosby-doing-a-white-guy voice—“‘Wow, this is exciting!’” A year later, after Johnson had proved he could make a ceramic membrane capable of withstanding temperatures above 400 degrees Celsius, the Air Force gave him an additional $750,000 in funding.
The key to the JTEC is the second law of thermodynamics. Simply put, the law says that temperature differences tend to even out—for instance, when a hot mug of coffee disperses its heat into the cool air of a room. As the heat levels of the mug and the room come into balance, there is a transfer of energy.
Work can be extracted from that transfer. The most common way of doing this is with some form of heat engine. A steam engine, for example, converts heat into electricity by using steam to spin a turbine. Steam engines—powered predominantly by coal, but also by natural gas, nuclear materials, and other fuels—generate 90 percent of all U.S. electricity. But though they have been refined over the centuries, most are still clanking, hissing, exhaust-spewing machines that rely on moving parts, and so are relatively inefficient and prone to mechanical breakdown.
Johnson’s latest JTEC prototype, which looks like a desktop model for a next-generation moonshine still, features two fuel-cell-like stacks, or chambers, filled with hydrogen gas and connected by steel tubes with round pressure gauges. Where a steam engine uses the heat generated by burning coal to create steam pressure and move mechanical elements, the JTEC uses heat (from the sun, for instance) to expand hydrogen atoms in one stack. The expanding atoms, each made up of a proton and an electron, split apart, and the freed electrons travel through an external circuit as electric current, charging a battery or performing some other useful work. Meanwhile the positively charged protons, also known as ions, squeeze through a specially designed proton-exchange membrane (one of the JTEC elements borrowed from fuel cells) and combine with the electrons on the other side, reconstituting the hydrogen, which is compressed and pumped back into the hot stack. As long as heat is supplied, the cycle continues indefinitely.
“Lonnie’s using temperature differences to create pressure gradients,” says Paul Werbos, an energy expert and program director of the National Science Foundation. “Only instead of using those pressure gradients to move an axle or a wheel, he’s forcing ions through a membrane.” Werbos, who spent months vetting the JTECand eventually awarded Johnson’s team a $75,000 research grant in 2006, describes the JTEC as “a fundamentally new way, a fundamentally well-grounded way, to convert heat to electricity.” Regarding its potential to revolutionize energy production on a global scale, he says, “It has a darn good chance of being the best thing on Earth.”
JOHNSON IS A MEMBER of what seems to be a vanishing breed: the self-invented inventor. Born the third of six children in Mobile, Alabama, in 1949, he came into the world a black male in the Deep South during the days of lawful segregation. His father, David, who died in 1984, was a World War II veteran and a civilian driver for nearby Air Force bases. According to his mother, Arline, who is 86 and still lives in Mobile (in a house remodeled with Super Soaker profits), the family was poor but happy. All eight lived in a three-bedroom, one-bathroom house near Mobile Bay, in a neighborhood then being bisected by the construction of Interstate 10.
As a boy, Johnson was quiet and curious, and early on, he developed a fascination with how things worked. “Lonnie tore up his sister’s baby doll to see what made the eyes close,” his mother recalls. As he grew older, he began making things, including rockets powered by fuel cooked up in his mother’s saucepans. At 13, he bolted a discarded lawn-mower engine onto a homemade go-cart and took it atop the I-10 construction site—only to have a bemused policeman escort him back down. It was around then that Johnson learned that “engineers were the people who did the kind of things that I wanted to do.”
It was hardly an obvious career path: then, as now, the profession was dominated by whites. (As recently as 2004, only 1.6 percent of the engineering doctorates awarded in the United States went to blacks.) In high school, a standardized test from the Junior Engineering Technical Society informed Johnson that he had little aptitude for engineering; but he persevered and, as a senior, became the first student from his all-black high school ever to enter the society’s regional engineering fair. The fair was held at the University of Alabama at Tuscaloosa, just five years after then-Governor George Wallace had tried, in 1963, to physically block two black students from enrolling there. Johnson’s entry in the competition was a creation he called Linex: a compressed-air-powered robot assembled from electromagnetic switches he’d salvaged from an old jukebox, and solenoid valves he’d fashioned out of copper tubing and rubber stoppers. The finished product wowed the judges, who awarded him first prize: $250 and a plaque. Unsurprisingly, university officials didn’t trumpet the news that a black boy had won top honors. “The only thing anybody from the university said to us during the entire competition,” Johnson remembers, “was ‘Goodbye, and y’all drive safe, now.’”

Stanford Unveils Solar Cells Thinner Than Light Wavelengths

by Timon Singh

One problem with solar cells is that the thicker and more powerful they are, the more expensive they are to make. However engineers at Stanford recently announced that they have developed a new type of solar cell thinner than the wavelengths of light that could absorb 10 times the amount of sunlight that current cells do. The engineers believe that by configuring the thicknesses of several thin layers of films, an organic polymer cell could transform the solar energy industry.

Stanford’s new ultra-thin solar cell stops the lights from bouncing around as it would in a conventional cell, allowing it to be absorbed more easily. This technique is called “light trapping”, and it works best in nano-thin cells. Speaking to PhysOrg.com, Shanhui Fan, associate professor of electrical engineering said, “It’s the same as if you were using hamsters running on little wheels to generate your electricity – you’d want each hamster to log as many miles as possible before it jumped off and ran away.”

“The longer a photon of light is in the solar cell, the better chance the photon can get absorbed,” Fan added, who is also senior author of the paper describing the work called Proceedings of the National Academy of Sciences. “We all used to think of light as going in a straight line,” Fan said. “For example, a ray of light hits a mirror, it bounces and you see another light ray. That is the typical way we think about light in the macroscopic world. But if you go down to the nanoscales that we are interested in, hundreds of millionths of a millimeter in scale, it turns out the wave characteristic really becomes important.”
With that in mind, if a solar cell can be made that is around 400 to 700 nanometers thin (billionths of a meter), it can produce a remarkable amount of energy. The potential for this technology is enormous — not only would nano-thin solar cells save money in materials, but by using organic polymers over silicon they make the cells cheaper to buy and easier to install due to their thickness.

Liquid Energy: New Microbe Tech Turns Sun and CO2 Into Fuel

by Timon Singh

Biofuel startup Joule Unlimited has announced that it has engineered microbes that require only sunlight and CO2 to produce ethanol, diesel, or other hydrocarbons. The company formally announced that it has obtained a patent for a genetically modified version of cyanobacteria that converts carbon dioxide, dirty water and sunlight into a liquid hydrocarbon that is functionally equivalent to regular diesel.

According to the patent, the engineered cyanobacteria contains “a recombinant acyl ACP reductase (AAR) enzyme and a recombinant alkanal decarboxylative monooxygenase (ADM) enzyme.”   What this concoction of cyanobacteria and enzymes does is allow for hydrocarbon production in a single step, converting captured sunlight into ‘liquid energy’, that can be either ethanol or diesel.

“This patent award represents a critical milestone for our IP strategy and validates the truly revolutionary nature of our process, which has the potential to yield infrastructure-compatible replacements for fossil fuels at meaningful scale and highly-competitive costs, even before subsidies,” said Bill Sims, President and CEO, Joule. “Our vision since inception has been to overcome the limitations of biomass-based technologies, from feedstock costs and logistics to inefficient, energy-intensive processing. The result is the world’s first platform for converting sunlight and waste CO₂ directly into diesel, requiring no costly intermediates, no use of agricultural land or fresh water, and no downstream processing.”
Formerly known as Joule Biotechnologies, the company, which is based in Cambridge, Massachusetts, announced late last year that it had developed technology which could produce the equivalent of 25,000 gallons of ethanol per acre per year and 15,000 gallons of diesel per acre per year of drop-in hydrocarbon fuels, using only sunlight, CO₂ and  water as inputs. The Solar Converter along with the new bacteria and a technology known as helioculture is the basis of this claim. Pilot production on diesel begins later this year.
While the project is still in its pilot testing phase, it’s already producing 10,000 gallons of ethanol a year, or 40 percent of its goal, on its pilot lines in Leander, Texas. It is expected that production will begin by the end of the year with commercial production commencing in 2012.  If it is successful, not only could it mean cheap biofuel (selling at $30 a barrel, compared to $70 for oil), but it could mean a fully sustainable form of fuel that doesn’t need food crops to create it. Fuel could literally be created out of thin air!

MIT’s Solar Funnel Concentrates Solar Energy 100 Times

by Timon Singh

A group of chemical engineers at MIT have devised a way to collect solar energy 100 times more concentrated than a traditional photovoltaic cell. If their ’solar funnel’ venture proves to be a success, it could drastically alter how solar energy is collected in the future — there will no longer be a need for massive solar arrays or extensive space to generate significant and sufficient amounts of power. The engineers’ research has determined that carbon nanotubes – hollow tubes made up of carbon atoms — will be the primary instrument in capturing and focusing light energy, allowing for not just smaller, but more powerful solar arrays.

In the Sept. 12 online edition of the journal Nature Materials, Michael Strano, the Charles and Hilda Roddey Associate Professor of Chemical Engineering and leader of the research team said, “Instead of having your whole roof be a photovoltaic cell, you could have little spots that were tiny photovoltaic cells, with antennas that would drive photons into them.” Their work is being funded by a National Science Foundation Career Award, a Sloan Fellowship, the MIT-Dupont Alliance and the Korea Research Foundation.

The antenna itself is incredibly small – it consists of a fibrous rope about 10 micrometers (millionths of a meter) long and four micrometers thick, containing about 30 million carbon nanotubes. The prototype made by Strano’s team consisted of a fiber made of two layers of nanotubes, each with different electrical properties.
When a photon strikes the surface of the solar funnel, it excites an electron to a higher energy level, which is specific to the material. The relationship between the energized electron and the hole it leaves behind is called an exciton, and the difference in energy levels between the hole and the electron is known as the bandgap.
The inner layer of the antenna contains nanotubes with a small bandgap, and nanotubes in the outer layer have a higher bandgap. Excitons like to flow from high to low energy, and in the solar funnel’s case means they can flow from the outer layer to the inner layer where they can exist in a lower energy state. When light strikes the antenna, all of the excitons flow to the center of the antenna where they are concentrated and the photons are converted to an electrical current. Like with all solar cells however, its efficiency depends on the materials utilized for the electrode.

Strano’s team is the first to construct nanotube fibers in which the properties of different layers can be controlled — an achievement made possible by recent advances in separating nanotubes with different properties. It is not just the higher rate of concentrated energy that makes the solar funnels a breakthrough — by utilizing carbon nanotubes, solar cells can be constructed at a lower-cost than traditional silicon-based solar cells.
While the cost of carbon nanotubes was once prohibitive, it has come down in recent years as chemical companies build up their manufacturing capacity. “At some point in the near future, carbon nanotubes will likely be sold for pennies per pound, as polymers are sold,” says Strano. “With this cost, the addition to a solar cell might be negligible compared to the fabrication and raw material cost of the cell itself, just as coatings and polymer components are small parts of the cost of a photovoltaic cell.”
In theory, with this new technology, not only could the solar funnels be used to generate power, but they could be used in applications where light needs to be concentrated — such as telescopes or night-vision goggles. The design behind the solar funnel is quite innovative, by capturing the light in a tube, Strano’s solar funnel, also know as an nanotube antenna, boosts the number of photons that can be transformed into energy, but in a similar process to that of tradition solar cells.
Strano’s team is now reportedly working on ways to minimize the energy lost as excitons flow through the fiber, as well as new antennas that would lose only 1 percent of the energy they absorb versus the standard 13 percent.

Cambridge University Produces Cheap Plastic Organic Solar Cell

by Timon Singh

The University of Cambridge has developed a low cost organic solar cell that has the potential to transform solar production. This new material is made of organic plastic and could be used on awnings, umbrellas and other plastic devices to generate energy.

By placing organic polymers (long chains of carbon-based molecules) in plastic you create an organic photovoltaic cell, that until now have not had much commercial success. With an operating principle similar to photosynthesis in green plants, organic photovoltaic cells are cheap to produce when compared to silicon solar cells, but have quite a low efficiency. This is something which the University of Cambridge is aiming to change.

The university team has reportedly come up with a commercial model that combines efficiency improvements, a longer lifespan, low-cost (and low-toxicity) raw materials, a cost-effective manufacturing process, and a product line that focuses on economies of scale and ease of installation. If this can be done, then cheaply produced solar cells have the ability to transform poorer countries and their energy demands.

The university’s Cavendish Laboratory and the Carbon Trust have formed a joint venture company to develop organic solar PV technology, which has been financed with a £4.5 million initial investment from the Trust and specialty chemicals firm Rhodia. Cavendish Labs have reportedly fine-tuned the capability for fabricating large-scale plastic electronic devices on flexible materials using roll-to-roll processes. The new company will be able to focus on developing organic photovoltaics (OPV) on flexible rolls, enabling them to be used more readily and discretely on buildings – and potentially other objects – than conventional rigid photovoltaic panels.
Not only can organic photovoltaic plastic be molded for any purpose, but it can be spray-painted on objects, be it buildings, cars or otherwise. There are also investigations in to creating a silicon-based solar paint, but if organic photovoltaic paint can be produced first, and more cheaply, then it could transform the solar market. Instead of acres of solar cells, cities could be transformed using solar plastics, not to mention the more environmental alternative – bioplastics, which are made from waste-water instead of petroleum.

More Solar

MIT Creates Self-Assembling Solar Cells That Repair Themselves

by Jaymi Heimbuch

MIT's Test Cell Patrick Gillooly, MIT
Solar cells are intended to mimic the photosynthesis of plants -- converting light into energy in the most efficient manner possible. But what other characteristics of plants could be handy for the renewable energy sector to mimic? How about the self-assembly of chloroplast, the component of plants that do all the vital photosynthesis. Leaves repair themselves after sun damage again and again to keep up their ability to convert light into energy. Now, MIT researchers believe they've discovered how to use this self-assembly to restore solar cells damaged by the sun.

Popular Science writes, "To recreate this unique regenerative ability, the MIT team devised a novel set of self-assembling molecules that use photons to shake electrons loose in the form of electricity. The system contains seven different compounds, including carbon nanotubes that provide structure and a means to conduct the electricity away from the cells, synthetic phospholipids that form discs that also provide structural support, and other molecules that self-assemble into "reaction centers" that actually interact with the incoming photons to release electrons."
These compounds can assemble themselves into structures able to harvest solar energy at an efficiency of about 40%. As they loose efficiency from damage, a surfacant can be spread across them to break down the compounds, then when it is filtered out, the cells reassemble good as new. The researchers think they can eventually boost the efficiency even higher, and perhaps provide solar cells that are virtually indestructible.
MIT is constantly coming out with new possibilities for the solar industry, from solar concentrators that improve both efficiency and designs, to printing thin film solar cells on paper. And now, perhaps, solar cells that bring us even closer to completely mimicking leaves.

SkyFuel’s SkyTrough is World’s Most Efficient Solar Concentrator

by Timon Singh

When it comes to producing solar power, efficiency is the key – efficiency of the panels, efficiency of the system’s collectors and, according to SkyFuel, efficiency of the solar concentrator technology. Solar concentrators are increasingly being used in the industry, due to their efficiency in providing cheap solar energy. By harnessing the sun’s energy, a solar concentrator can provide the necessary heat for dozens of homes and thus save electricity. As such, the systems are more efficient than regular solar generators as captured power is not just converted into electricity. But according to SkyFuel, a U.S.-based company, their SkyTrough solar concentrator technology has a thermal efficiency of 73% at 350˚C (662˚F). More than just a shallow claim, their statement has been confirmed by the National Renewable Energy Laboratory (NREL), which has certified the SkyTrough solar concentrator technology to have the highest efficiency in its class!

 

Performance of the optical elements of the SkyTrough was measured at the Optical Efficiency Test Loop in Golden, Colorado. The test facility was designed to allowed the study of the optical performance independent of the receiver’s heat loss characteristics. Optical efficiency is a direct gauge of the design elements unique to the SkyTrough’s mirror reflectance, parabolic accuracy, receiver alignment to the focal line of the trough, and the system’s tracking precision. ”The SkyTrough solar collector is a new, low-weight design that takes advantage of the patented reflector film jointly developed by SkyFuel and NREL,” said Chuck Kutscher, Principal Engineer and Manager of NREL’s Thermal Systems Group.
In a statement from SkyFuel, the company’s Chief Technology Officer Randy Gee said, “A lot of thoughtful engineering went into the SkyTrough, so we were confident our efficiency would be high, but NREL’s confirmation really validates our technology. We couldn’t be more pleased with NREL’s assessment.”
Parabolic trough solar concentrators, such as the SkyTrough, are designed to harness the sun’s energy to make steam for electricity generation. The more efficiently that a trough can harness the sun’s energy and convert it to steam, the more electricity it will be able to make. In the SkyTrough’s case, nearly three quarters of the solar radiation is thus converted into thermal energy, and then into electricity – a very high figure for solar power production. The fact that the thermal-to-electricity loss is only 27% is quite remarkable considering the large losses of efficiency that occur within the industry.

Global Solar rolls out stick-on solar panels

by Martin LaMonica

Glue may be the magic ingredient to making solar power cheaper.
Solar company Global Solar introduced a line of flexible solar modules which are designed for flat commercial rooftop buildings.
Rather than install racking systems to hold heavy glass-covered solar panels, the company's PowerFlex BIPV modules can be adhered onto a roof or built right into roofing materials. The modules are quicker to installer, lighter, and don't require any penetrations into the roof, according to the company.
The installed cost of Global Solar modules is about the same as traditional polycrystalline silicon panels with racks, said Jean-Noel Poirier, the vice president of marketing and business development. But because there is no need for spacing between racks, the flexible thin-film modules can cover more roof space and generate more power, he said.
The company plans to sell its solar modules--long strips of solar panels which almost 19 feet long and one and a half feet wide--through roof membrane manufacturers. The solar cells are made from a combination of copper, indium, selenium, and gallium (CIGS) and perform comparatively well in areas that don't have direct sun, Poirier said.
The company plans to get certification for the modules, which are being evaluated by roofing membrane companies now, by the end of the year and start production early next year.
Global Solar, one of many solar companies developing CIGS solar cells and modules, now has 75 megawatts worth of production capacity at two plants in Tucson, Arizona and Berlin, Germany. Until now, the company has supplied solar cells to panel manufacturers, but the company is now manufacturing its own modules for building-integrated photovoltaics, said CEO Jeff Britt.

New Black Silicon Solar Cells are Cheap and Absorb More Sun

by Brit Liggett

While the reflective and shiny solar panels that researchers have been making thus far look pretty, they’re no match for the National Renewable Energy Laboratory’s (NREL) recently discovered black silicon solar cell. The scientists at NREL discovered that etching thousands of tiny holes into a silicon wafer causes it to be almost black and thus able to absorb almost all of the sun’s rays, and more absorbent solar cells mean more efficient panels.

 

We recently reported on researchers that are using off the shelf dyes to help solar cells absorb a wider range of light but this experiment goes even further. No color can stand up to black when it comes to absorbing . Black doesn’t bounce anything back – it hoards all photons for itself. The researchers got the idea from a team in Munich that had carefully placed a thin layer of gold and some fancy chemicals on their silicon to turn it black.
By mixing gold and chemicals into a cocktail and spraying it on silicon, they were able to create a black silicon wafer in under 3 minutes at room temperature. At 100 degrees Fahrenheit they can do it in less than a minute — this bodes well for mass manufacturing. They call their black silicon wet-etched, because the chemical and gold mixture is wet when applied and etches holes into the substance. Their next effort — and its a big one — is engineering a workable solar panel around their etched silicon.

"Traditional" Design Meets Passive House Efficiency

"Traditional" Design Meets Passive House Efficiency In Oregon

by Lloyd Alter

Images via owners' website
Most Passivhaus or Passive House designs we have shown on TreeHugger have tended to be modern, but Sarah Evans and Stuart Rue tell Green Building Advisor that "We wanted our house to fit in with the surrounding neighbourhood." At Jetson Green, a commenter makes the point that "It is nice to see more traditional styling reaching higher levels of performance. Many people aren't up for the boxiness of the modern design and the trend in green homes has been so modern that many folks think that is all that can be green."

But I will point out that it is hard to do good traditional design to Passive House standards, because the engineering drives so much of the design. That's why none of the blogs covering this house show the straight-on front elevation; it becomes obvious that the windows on the east side are way too small and out of proportion. Traditional design has rules, as does Passive design, and it is obvious from this photograph that the rules are different.

One might also point out that this house is no less boxy than the modern passive house designs we have shown; it is in fact a perfect box. Every jog and corner is a problem in passive house design as it creates an opportunity for a thermal bridge. The only place that the talented architect Nathan Good could have any jogging fun was with the garages.
But once one gets past the issue of style, Stuart Rue and Sarah Evans have built a great demonstration of how Passive House design really can work to make a comfortable, healthy home that runs virtually on body heat.

The walls are double-stud with almost a foot of Greenfiber cellulose insulation (made from recycled newspaper, you can still read bits of it). Windows are our favourite Serious Windows, with a U value of .105 (R 9.52, which is why even with the best windows in the country you have to be careful of how big they are and where you put them.) Serious Windows has posted a video of the builder, explaining the house.
The only mechanical heating and cooling in the house is a mini-spit heat pump with 12,000 BTU of heat and 9,000 of cooling. Some houses use that much energy for their bedroom.

Inside, they have used natural materials (wool carpets, wood floors) and minimized the use of products with VOCs. The owners have been writing a terrific and thorough blog about the process, while the builder, Bilyeu Homes, did a thorough presentation about it for the Passive House Northwest Regional Meeting in April.
Nice work, even if I have trouble calling it "Traditional."

Photovoltaic Solar Hot Water Panels Reap Multiple Benefits

by Philip Proefrock

Solar panel manufacturer Solimpeks is offering a hybrid solar panel that is capable of providing both electricity and water heating from the same panel. The panels are ideal for applications where there is limited roof space available, but both solar electricity and solar hot water are desired. Even better, the combination of the two functions actually improves the efficiency of the electrical generation of the photovoltaics.

These hybrid panels address a problem most solar panels have: as photovoltaic (PV) panels get hotter, they get less efficient at generating electricity. A PV panel is about 1% less efficient for every 3.5 degrees F temperature increase. TheSolimpeks panels address this by using water to absorb excess heat and keep the panels cooler. Water cooling is far more effective than air cooling, making this a very effective combination. The heated water is then used to provide the additional benefit of hot water for the building.
Testing has shown the efficiency of electrical generation to be as high as 28% while at the same time producing 140-160 degree F water. This works out to an improvement of 20% over a similar sized electric-only PV array, and without the added hot water benefit, either.
Keeping the panels cooler has the additional benefit of extending their lifespan, keeping them in service for a longer period of time. These panels will also be able to pay back their installation cost more quickly since they are providing both electricity and hot water.

 

 

Sonnenschiff: Solar City Produces 4X the Energy it Consumes

by Andrew Michler

 

 

Although net-zero projects have been creating a lot of buzz lately in the field of green building, the Sonnenschiff solar city in Freiburg, Germany is very much net positive. The self-sustaining city accomplishes this feat through smart solar design and lots and lots of photovoltaic panels pointed in the right direction. It seems like a simple strategy -- but designers often incorporate solar installations as an afterthought, or worse, as a label. Designed byRolf Disc, the Sonnenschiff (Solar Ship) and Solarsiedlung (Solar Village) emphasize power production from the start by smartly incorporating a series of large rooftop solar arrays that double as sun shades. The buildings are also built to Passivhaus standards, which allows the project to produce four times the amount of energy it consumes!

  

The project started out as a vision for an entire community — the medium-density project balances size, accessibility, green space, and solar exposure. In all, 52 homes make up a neighborhood anchored to Sonnenschiff, a mixed-use residential and commercial building that emphasizes livability with a minimal footprint. Advanced technologies like phase-change materials and vacuum insulation significantly boost the thermal performance of the building’s wall system.

 

The homes are designed to the Passivhaus standard and have great access to passive solar heating and daylight. Each home features a very simple shed roof with deep overhangs that allows winter sun in while shading the building from the summer sun. The penthouses on top of the Sonnenschiff have access to rooftop gardens that make full use of the site’s solar resources. The rooftops feature rainwater recycling systems that irrigate the gardens and while supplying the toilets with greywater. The buildings also make use of wood chip boilers for heat in the winter, further decreasing their environmental footprint.
The project’s simple envelope design is brightened by a colorful and dynamic façade. Gardens and paths cross through the development as well, linking the inhabitants. Offices and stores expand the livability of the community while contributing a sense of communal purpose.

Personal Hygiene- toothbrush and razor no longer throwaway

Solar Powered Toothbrush Could Make Toothpaste Obsolete

by Yuka Yoneda

When we first saw this new gadget, we thought “Oh, a mechanical toothbrush powered by the sun.” But that isn’t what this is. Instead of using solar rays to charge itself up, the toothbrush uses them to catalyze a powerful chemical reaction that could leave your mouth way cleaner than regular old brushing does. “You see complete destruction of bacterial cells,” says Kunio Komiyama, the inventor of the device. Oh, and did we mention that no toothpaste is required? Watch out Colgate!

  

Mechanical University of Saskatchewan dentistry professor emeritus Dr. Kunio Komiyama and his colleague Dr. Gerry Uswak are recruiting 120 teens willing to brush with a prototype light-powered toothbrush and sit in a dentist’s chair for a few extra inspections. The manufacturer, the Shiken company of Japan, is paying the researchers to investigate whether the brush, which causes a chemical reaction in the mouth, does a better job of eliminating plaque and bacteria than a conventional toothbrush.
Komiyama’s first model, which was described 15 years ago in the Journal of Clinical Periodontology, contained a titanium dioxide rod in the neck of the brush, just below the nylon bristles. It works when light shines on the wet rod, releasing electrons. Those electrons react with acid in the mouth, which helps break down plaque. No toothpaste is required.
Now Komiyama’s back with a newer model, the Soladey-J3X, which he says packs twice the chemical punch compared to the original. Protruding from the base of the brush is a solar panel, which transmits electrons to the top of the toothbrush through a lead wire. It won’t work in the dark, though – the brush needs about as much light as a solar-powered calculator would to operate.

Synthetic Diamonds Offer Key to Razor Blades That Last Years, Not Weeks

by Jasmin Malik Chua

Photo by dotbenjamin
Hair today, gone tomorrow? A diamond-tipped razor blade from Germany could soon supplant its disposable counterpart in the face-shaving department—and we’re not just splitting follicles. Developed by Gesellschaft für Diamantprodukte(GFD) in Ulm, the Diamaze PSD comprises a tungsten carbide blade that is coated with a film of synthetic, industrial-grade diamonds. Sharpened to produce a cutting edge of only a few nanometers, the blade is said to last 1,000 times longer than conventional steel, meaning it stays sharp for years, rather than weeks.

BLEEDING EDGE

The Ulm-based company has been manufacturing blades coated with synthetic diamonds for almost a decade, albeit for less-glamourous equipment such as medical scalpels, drill bits, and probe needles. That was before Andre Flöter, founder of GFD, had the brainwave to apply diamond’s near-invulnerability to break into the multibillion-dollar consumer razor industry.

GFD engineers use a “plasma-sharpening” process to create a cutting edge as small as 3 nanometers.

But toughness isn’t the only quality the hirsute look for in razors. To ensure a clean, close shave, GFD engineers use a “plasma-sharpening” process that involves sticking dozens of blades upright in a vacuum chamber and then pummeling them with oxygen or chlorine gas that has been excited to a plasma state. The resulting radius of curvature at the cutting edge, according to GFD, can be as small as 3 nanometers—or only a few atoms in width.
Of course, blades manufactured this way would cost a lot more than conventional ones, but Flöter insists that they’ll pay for themselves in the long term. “If one adds together the costs of disposable razors over the period of one year,” he says, “then our diamond blade could certainly be a reasonably priced alternative.”

Transparent Solar Spray Transforms Windows Into Watts

by Cameron Scott

Photo by Robert S. Donovan
Norwegian Company EnSol AS has developed a remarkable new spray-on solar film that allows windows to generate solar power without clouding the view. The material consists of metal nanoparticles embedded in a transparent composite matrix that can be easily sprayed on. And the cells don’t just work on glass — they can be used on the rest of the house, too!

 Electron microscope image of EnSol nanocrystals

Inhabitat has brought you a number of technologies that make it possible to create ultra-thin solar cells, making them far more versatile. But there’s something particularly satisfying about EnSol AS’ new transparent spray-on solar film.
Lead researcher Christopher Binns of the University of Leicester said, “The coating would be built into the windows or other materials as part of the manufacturing process. It could even be used on the roofs of cars to charge up batteries — although powering the vehicles themselves would probably be pushing it.”
Perhaps EnSol’s slogan should be Solar: It’s not just for rooftops anymore. The cells achieve efficiencies of 20 percent (which is average) and the company claims they will be commercially available at a reasonable price by 2016.

Light-Bending Polymer Sticker Boosts Solar Panel Output by 10%

by Jasmin Malik Chua

Looking for an instant power boost for your solar panels? Slap on a large, transparent sticker by Genie Lens Technologies to get 10 percent more juice. The polymer film, which can be applied to panels you already have installed, comes riddled with microstructures that bend incoming sunlight for better absorption. More light equals more electricity, which in turn lowers the per-watt cost of solar power.


The inexpensive film works by preventing light from bouncing off the surface of the panel, according to Seth Weiss, the company’s CEO and co-founder. Not only does the sticker trap light inside the semiconductor materials that convert light into electricity, but it also diverts incoming rays so that they travel across — rather than through— the panel, bettering their chances of being absorbed.
Tests at the National Renewable Energy Laboratory showed that the film increases power output by between 4 to 12.5 percent, with the biggest improvement occurring when the sky is overcast and incoming light is diffuse. Although adding the sticker, whether in the factory or on solar panels already installed, raises the overall cost of the panels by 1 to 10 percent, the additional electricity generated makes up for the price.
A more efficient solar panel also means getting by with fewer solar panels, according to Travis Bradford, a solar industry analyst and president of the Prometheus Institute. As a result, other costs such as shipping and installation could also drop. Just one downside: Although the film has been rated for 20 years, it hasn’t been tested for durability — scratches, discoloring, and trapped dust can actually lower power output over time.

 

 

 

80% Cheaper Solar Cells Switch Gold For Nickel

by Brit Liggett

One of the major drawbacks of most renewable energy sources is high cost. In order to see a huge rise in the use of renewable energy sources, prices must come down. In the world of solar there have recently been some major breakthroughs in cost advantages and efficiency increases. Scientists at the University of Toronto in Canada have come up with a way to reduce colloidal quantum dot solar cell prices by up to 80%, by swapping out costly conductive gold for cheap nickel.



Quantum dot solar cells consist of a silicon substrate that has a thin film coating of nanocrystals — or quantum dots. Gold was previously used as the conductive material in the cells and when scientists tried to switch the gold out for nickel the nickel formed new particles with the quantum dots that weren’t able to capture energy. Scientists at the University of Toronto led by Dr. Ratan Debnath found that increasing the layer of silicon substrate created a big enough barrier between the dots and the nickel that the solar cells became effective at the expected efficiency levels.
The team at University of Toronto published their findings in a paper in the July 12, 2010 issue of Applied Physics Letters and noted that with further research they believe that they will be able to increase the efficiency of their extremely inexpensive quantum dot solar panels and make them look attractive to consumers when they eventually hit the market. Unlike conventional solar panels, the quantum dot solar cells that the University of Toronto invented capture visible and infrared light. Though a mode for large scale production still hasn’t been found the impacts of these super-cheap cells could be huge.