Tagged: Solar Power Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 10:41 am on August 26, 2015 Permalink | Reply
    Tags: , , , , Solar Power   

    From ars technica: “Quantum dots may be key to turning windows into photovoltaics” 

    Ars Technica
    ars technica

    Aug 26, 2015
    John Timmer

    Some day, this might generate electricity. Flickr user Ricardo Wang

    While wind may be one of the most economical power sources out there, photovoltaic solar energy has a big advantage: it can go small. While wind gets cheaper as turbines grow larger, the PV hardware scales down to fit wherever we have infrastructure. In fact, simply throwing solar on our existing building stock could generate a very large amount of carbon-free electricity.

    But that also highlights solar’s weakness: we have to install it after the infrastructure is in place, and that installation adds considerably to its cost. Now, some researchers have come up with some hardware that could allow photovoltaics to be incorporated into a basic building component: windows. The solar windows would filter out a small chunk of the solar spectrum and convert roughly a third of it to electricity.

    As you’re probably aware, photovoltaic hardware has to absorb light in order to work, and a typical silicon panel appears black. So, to put any of that hardware (and its supporting wiring) into a window that doesn’t block the view is rather challenging. One option is to use materials that only capture a part of the solar spectrum, but these tend to leave the light that enters the building with a distinctive tint.

    The new hardware takes a very different approach. The entire window is filled with a diffuse cloud of quantum dots that absorb almost all of the solar spectrum. As a result, the “glass” portion of things simply dims the light passing through the window slightly. (The quantum dots are actually embedded in a transparent polymer, but that could be embedded in or coat glass.) The end result is what optics people call a neutral density filter, something often used in photography. In fact, tests with the glass show that the light it transmits meets the highest standards for indoor lighting.

    Of course, simply absorbing the light doesn’t help generate electricity. And, in fact, the quantum dots aren’t used to generate the electricity. Instead, the authors generated quantum dots made of copper, indium, and selenium, covered in a layer of zinc sulfide. (The authors note that there are no toxic metals involved here.) These dots absorb light across a broad band of spectrum, but re-emit it at a specific wavelength in the infrared. The polymer they’re embedded in acts as a waveguide to take many of the photons to the thin edge of the glass.

    And here’s where things get interesting: the wavelength of infrared the quantum dots emit happens to be very efficiently absorbed by a silicon photovoltaic device. So, if you simply place these devices along the edges of the glass, they’ll be fed a steady diet of photons.

    The authors model the device’s behavior and find that nearly half the infrared photons end up being fed the photovoltaic devices (equal amounts get converted to heat or escape the window entirely). It’s notable that the devices are small, though (about 12cm squares)—larger panes would presumably allow even more photons to escape.

    The authors tested a few of the devices, one that filtered out 20 percent of the sunlight and one that only captured 10 percent. The low-level filter sent about one percent of the incident light to the sides, while the darker one sent over three percent.

    There will be losses in the conversion to electricity as well, so this isn’t going to come close to competing with a dedicated panel on a sunny roof. Which is fine, because it’s simply not meant to. Any visit to a major city will serve as a good reminder that we’re regularly building giant walls of glass that currently reflect vast amounts of sunlight, blinding or baking (or both!) the city’s inhabitants on a sunny day. If we could cheaply harvest a bit of that instead, we’re ahead of the game.

    Nature Nanotechnology, 2015. DOI: 10.1038/NNANO.2015.178 (About DOIs).

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon
    Stem Education Coalition
    Ars Technica was founded in 1998 when Founder & Editor-in-Chief Ken Fisher announced his plans for starting a publication devoted to technology that would cater to what he called “alpha geeks”: technologists and IT professionals. Ken’s vision was to build a publication with a simple editorial mission: be “technically savvy, up-to-date, and more fun” than what was currently popular in the space. In the ensuing years, with formidable contributions by a unique editorial staff, Ars Technica became a trusted source for technology news, tech policy analysis, breakdowns of the latest scientific advancements, gadget reviews, software, hardware, and nearly everything else found in between layers of silicon.

    Ars Technica innovates by listening to its core readership. Readers have come to demand devotedness to accuracy and integrity, flanked by a willingness to leave each day’s meaningless, click-bait fodder by the wayside. The result is something unique: the unparalleled marriage of breadth and depth in technology journalism. By 2001, Ars Technica was regularly producing news reports, op-eds, and the like, but the company stood out from the competition by regularly providing long thought-pieces and in-depth explainers.

    And thanks to its readership, Ars Technica also accomplished a number of industry leading moves. In 2001, Ars launched a digital subscription service when such things were non-existent for digital media. Ars was also the first IT publication to begin covering the resurgence of Apple, and the first to draw analytical and cultural ties between the world of high technology and gaming. Ars was also first to begin selling its long form content in digitally distributable forms, such as PDFs and eventually eBooks (again, starting in 2001).

  • richardmitnick 4:22 pm on August 23, 2015 Permalink | Reply
    Tags: , , Solar Power,   

    From Yale: “With Polymer Blend, Researchers Develop More Efficient Solar Cells” 

    Yale University bloc

    Yale University

    No Writer Credit


    Yale researchers have significantly increased the efficiency of a polymer solar cell by using a technique that mimics how plants use solar energy and forcing two otherwise incompatible molecules to work together to cover the full color spectrum.

    The researchers, in Dr. Andre Taylor’s Transformative Materials & Devices Lab, developed a solar cell that performed 22.5 percent better than conventional organic solar cells. Their results were published online this month in the Journal of Materials Chemistry A demonstrating a power conversion efficiency of 8.7 percent.

    Most commercial solar cells today are made from silicon. But polymer cells cost less and weigh less, making them an appealing alternative. The problem is that they’re not very efficient – they fail to convert nearly half their absorbed light energy to electrical power. That’s partly because the polymers used in these cells don’t line up well enough to allow energy to exit the cell easily.

    However, because polymers have a mechanical flexibility that silicon cells don’t, researchers are hopeful that they will find ways around these shortcomings.
    “We are starting to approach the limits for improvements that can done with conventional silicon solar cells,” Taylor said. “But with organic polymers you can tweak and do things to them with significant results.”

    In a 2013 study in Nature, Taylor’s lab was the first to show that this can occur between small molecules and a polymer known as P3HT. It’s now demonstrating some of those same benefits in polymer blends.

    Conventional organic solar cells, known as binary solar cells, have one polymer serving as an electron donor and a fullerene derivative as the electron acceptor. Ternary cells – the kind used in this study – can have either two donors and one acceptor or one donor and two acceptors. In most cases, though, more efficient ternary cells usually have two donors and one acceptor since donors are predominantly responsible for light absorption.

    The most recent study uses two polymers, P3HT and PTB7, which are both light-sensitive molecules known as chromophores. In one sense, the two are complementary: P3HT absorbs the blue-green side of the light spectrum, while PTB7 absorbs primarily at the yellow-red spectrum. Together, the two cover a large portion of the visible-light spectrum. Rather than working independently, the proximity of the two polymers also facilitates what’s known as Förster resonance energy transfer (FRET) to occur. That’s when energy is transferred between two chromophores over long distances.

    The problem is how these two polymers align.

    “We are blending two different types of polymers, so they align in different ways,” said TengHooi Goh, lead author of the paper. “P3HT aligns in a way that it stands like a wall and PTB7 is positioned more like a stack of pancakes.”

    “They work well optically, but the contradicting alignment is bad for electron transport,” added Taylor, senior author of the paper.

    To get around this problem, the researchers used a technique known as solvent vapor annealing (SVA), in which they chemically modify the properties of the polymers to better align. The more commonly used method is thermal annealing, but heat has been found to diminish the performance of the polymers. Goh said that SVA can potentially solve incompatible alignment problems in complex polymer systems and drive the efficiency of organic photovoltaics to a new heights.

    The other authors of the paper, Panchromatic Polymer-polymer Ternary Solar Cells Enhanced by Förster Resonance Energy Transfer and Solvent Vapor Annealing, are Jing-Shun Huang, Benjamin Bartolome,Matthew Y. Sfeir, Michelle Vaisman, and Minjoo Lee.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Yale University Campus

    Yale University comprises three major academic components: Yale College (the undergraduate program), the Graduate School of Arts and Sciences, and the professional schools. In addition, Yale encompasses a wide array of centers and programs, libraries, museums, and administrative support offices. Approximately 11,250 students attend Yale.

  • richardmitnick 9:53 am on August 18, 2015 Permalink | Reply
    Tags: , , Solar Power   

    From wired: “How Much Can You Save With Solar Panels? Just Ask Google” 

    Wired logo


    Cade Metz


    If you’re considering solar power but aren’t quite sure it’s worth the expense, Google wants to point you in the right direction. Tapping its trove of satellite imagery and the latest in artificial intelligence, the company is offering a new online service that will instantly estimate how much you’ll save with a roof full of solar panels.

    The first three concentrated solar power (CSP) units of Spain’s Solnova Solar Power Station in the foreground, with the PS10 and PS20 solar power towers in the background

    On Monday, the company unveiled Project Sunroof, a tool that calculates your home’s solar power potential using the same high-resolution aerial photos Google Earth uses to map the planet. After creating a 3-D model of your roof, the service estimates how much sun will hit those solar panels during the year and how much money the panels could save you over the next two decades. “People search Google all the time to learn about solar,” says Google’s Joel Conkling. “But it would be much more helpful if they could learn whether their particular roof is a good fit.”


    The service is now available for homes in the San Francisco Bay Area, central California, and the greater Boston area. Google is headquartered in California, you see, and project creator Carl Elkin lives in Boston. Based in the company’s Cambridge offices, Elkin typically works on Google’s search engine, but he developed Project Sunroof during his “20 percent time“—that slice of the work week Googlers can use for independent projects.

    How Google Parses Your Roof

    Elkin’s own home has solar panels, and he once volunteered with Solarize Massachusetts to promote solar in the Bay State. He and Google see Project Sunroof pushing solar use further still. “We people want to go solar but don’t understand how cheap it is,” Elkin says. “I wanted people to understand that they can actually save money.”

    As Google notes in a blog post announcing Project Sunroof, the time is ripe for such a tool. “This is an extremely useful thing,” says Roland Winston, a professor at the University of California, Merced, who specializes in solar energy. “Solar technology is cheaper than ever.” Indeed, others have developed services along these lines, including academics and companies like Geostellar and Mapdwell.

    But Google’s service is a bit different. It has Google behind it—and the company is taking a particularly comprehensive approach. In analyzing satellite images of your home, Google uses “deep learning” neural networks to separate your roof from the surrounding trees and shadows. “Even a strong solar advocate like me wouldn’t recommend putting solar panels on your trees,” Elkin says. Mimicking the web of neurons in the human brain, this sort of neural network is the same technology used to recognize faces on Facebook or instantly translate from one language to another on Skype.

    Project Sunroof also simulates the shadows that typically cover your home on any given day (see animation above), and it tracks local weather patterns. “We’re able show how much energy is hitting each part of your roof,” Conkling says. And if you like, you can further hone that company’s calculations by providing how much you typically spend on electricity (otherwise, the service relies on public utility rates in your area).

    Beyond Elkin’s personal crusade, Google has a long history of advocating for solar power. In addition to investing in solar as a means of powering its global network of data centers, the company previously has invested in residential solar projects. But this isn’t mere charity work. Project Sunroof also recommends solar providers in your area, and it plans to eventually take a referral fee from these providers. “We want to help people understand the potential of solar power,” says Conkling. “But we can make some money off of that as well.”

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

  • richardmitnick 12:35 pm on December 27, 2014 Permalink | Reply
    Tags: , , Solar Power   

    From Discovery: “World’s Largest Floating Solar Plant Planned for Japan” 

    Discovery News
    Discovery News

    Dec 24, 2014
    Glenn McDonald

    An image of the Kyocera Corporation’s existing Kagoshima Nanatsujima power plant in Japan. The company’s new project will be the largest fully-floating solar installation in the world.


    If you’ve ever been out in a boat on a hot summer day, you know that open water gathers a lot of sun and heat. Engineers in Japan are hoping to harness that power with the construction of what will be the planet’s largest floating solar power installation.

    Japan’s Kyocera Corporation has already leveraged the power of open water with shoreline solar installations like the fixed Kagoshima Nanatsujima plant, pictured above. The new project, however, will be built around 50,000 solar collection modules actually afloat on the Yakamura Dam reservoir.

    The modules will cover a water surface area of around 180,000 square meters. Engineers estimate the plant will generate more than 15.6 megawatt hours (MWh) per year. That’s enough to power approximately 4,700 average households.

    More numbers: According to the company’s projections, the floating power plant will gather enough solar power from the surface of the dam to offset about 7,800 tons of carbon dioxide emissions annually. The facility will also include an education center adjacent to the plant, to provide classes for local students on environmental issues.

    Floating Nuclear Plant Would Ride Out Tsunamis

    “When we first started R&D for solar energy in the mid 1970’s, the technology was only viable for small applications such as street lamps, traffic signs and telecommunication stations in mountainous areas,” said Nobuo Kitamura, Kyocera senior executive officer, in press materials for the project.

    “Since then, we have been working to make solar energy use more ubiquitous in society. We are excited to work with our partners on this project, taking another step forward by utilizing untapped bodies of water as solar power generation sites.”

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

  • richardmitnick 1:50 pm on August 19, 2013 Permalink | Reply
    Tags: , , , , Solar Power   

    From Brookhaven Lab: “Polymer Solar Cells Employing Förster Resonance Energy Transfer” 

    Brookhaven Lab

    August 19, 2013
    No Writer Credit

    What is the Scientific Achievement?

    Two crucial tasks exist for realizing high-efficiency polymer solar cells: increasing the range of the spectral absorption of light and efficiently harvesting photo-generated excitons. In this work, Förster resonance energy transfer (FRET)-based heterojunction polymer solar cells that incorporate squaraine dye (SQ) were fabricated and investigated. The high absorbance of squaraine in the near-infrared region broadens the spectral absorption of the solar cells and assists in developing an ordered nano-morphology for enhanced charge transport. Femtosecond spectroscopic studies revealed highly efficient (up to 96%) excitation energy transfer from poly(3-hexylthiophene), also known as P3HT, to squaraine occurring on a picosecond timescale. A 38% increase in power conversion efficiency was realized to reach 4.5%; this finding suggests that this system has improved exciton migration over long distances. This architecture transcends traditional multiblend systems, allowing multiple donor materials with separate spectral responses to work synergistically, thereby enabling an improvement in light absorption and conversion. This discovery opens up a new avenue for the development of high-efficiency polymer solar cells.

    Next generation solar panels could yield substantially lower costs per kilowatt-hour with this technological development.

    Why Does This Matter?

    A new energy transfer mechanism has been exploited for the first time, allowing significantly more efficient energy harvesting in P3HT/dye solar cells compared to P3HT-alone solar cells. Also, broadening the light absorption spectrum into the near-infrared region and developing nanoscale parts to the solar cell has improved the device.

    Energy level diagram of the components of the ternary blend solar cell highlighting pathways for charge generation.

    Allowing different light-absorbing materials to work synergistically has led to well-ordered polymer networks without post-processing.”

    See the full article here.

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

    ScienceSprings is powered by MAINGEAR computers

  • richardmitnick 12:44 pm on August 5, 2013 Permalink | Reply
    Tags: , , , , , , Solar Power   

    From Stanford: “Disorder can improve the performance of plastic solar cells, Stanford scientists say” 

    Stanford University Name
    Stanford University

    Instead of mimicking rigid solar cells made of silicon crystals, scientists should embrace the inherently disordered nature of plastic polymers, a Stanford study has found

    August 4, 2013
    Mark Shwartz

    “Scientists have spent decades trying to build flexible plastic solar cells efficient enough to compete with conventional cells made of silicon. To boost performance, research groups have tried creating new plastic materials that enhance the flow of electricity through the solar cell. Several groups expected to achieve good results by redesigning pliant polymers of plastic into orderly, silicon-like crystals, but the flow of electricity did not improve.

    Recently, scientists discovered that disorder at the molecular level actually improves the polymers’ performance. Now Stanford University researchers have an explanation for this surprising result. Their findings, published in the Aug. 4 online edition of the journal Nature Materials, could speed up the development of low-cost, commercially available plastic solar cells.

    These X-ray images reveal the microscopic structure of two semiconducting plastic polymers. The bottom image, with several big crystals stacked in a row, is from a highly ordered polymer sample. The top image shows a disordered polymer with numerous tiny crystals that are barely discernible.

    ‘People used to think that if you made the polymers more like silicon they would perform better,’ said study co-author Alberto Salleo, an associate professor of materials science and engineering at Stanford. ‘But we found that polymers don’t naturally form nice, well-ordered crystals. They form small, disordered ones, and that’s perfectly fine.’

    Instead of trying to mimic the rigid structure of silicon, Salleo and his colleagues recommend that scientists learn to cope with the inherently disordered nature of plastics.”

    X-ray analysis

    To observe the disordered materials at the microscopic level, the Stanford team took samples to the SLAC National Accelerator Laboratory for X-ray analysis. The X-rays revealed a molecular structure resembling a fingerprint gone awry. Some polymers looked like amorphous strands of spaghetti, while others formed tiny crystals just a few molecules long.

    ‘The crystals were so small and disordered you could barely infer their presence from X-rays,’ Salleo said. ‘In fact, scientists had assumed they weren’t there.’

    By analyzing light emissions from electricity flowing through the samples, the Stanford team determined that numerous small crystals were scattered throughout the material and connected by long polymer chains, like beads in a necklace. The small size of the crystals was a crucial factor in improving overall performance, Salleo said.

    Other authors of the study are postdoctoral scholar Koen Vandewal of Stanford; Felix Koch and Paul Smith of ETH Zurich; Natalie Stingelin of Imperial College London; and Michael Toney of the SLAC Stanford Synchrotron Radiation Lightsource.”

    See the full article here.

    Leland and Jane Stanford founded the University to “promote the public welfare by exercising an influence on behalf of humanity and civilization.” Stanford opened its doors in 1891, and more than a century later, it remains dedicated to finding solutions to the great challenges of the day and to preparing our students for leadership in today’s complex world. Stanford, is an American private research university located in Stanford, California on an 8,180-acre (3,310 ha) campus near Palo Alto. Since 1952, more than 54 Stanford faculty, staff, and alumni have won the Nobel Prize, including 19 current faculty members

    Stanford University Seal

    ScienceSprings is powered by MAINGEAR computers

  • richardmitnick 11:28 am on May 21, 2013 Permalink | Reply
    Tags: , Solar Power   

    From Brookhaven Lab: “Soaking Up Sun at the Long Island Solar Farm for Energy Research at Brookhaven Lab” 

    Brookhaven Lab

    May 16, 2013
    Pat Looney

    “Bring on the sunshine! April showers are behind us and the sun is shining a little longer each day in the northern hemisphere. That means the 200-acre Long Island Solar Farm (LISF) at Brookhaven Lab is producing increasing amounts of renewable energy for Long Islanders and data for our researchers.

    The 200-acre Long Island Solar Farm (LISF) is located at the east end of Brookhaven Lab. By hosting the LISF and future Northeast Solar Energy Research Center on site, Brookhaven Lab has positioned itself at the forefront of new research to help develop real-world solar energy technologies.

    The LISF is the largest solar array in the eastern U.S. and is located at the east end of the Lab site. It contains 164,312 photovoltaic panels grouped and mounted onto more than 6,800 racks. The LISF can produce peak power output of 32 megawatts (MW) of alternating current that powers homes and businesses. Operations began in November 2011, and during its first 12 months, the LISF produced a total of about 54,000 megawatt-hours (MWH) of energy. That’s 23 percent more than the design estimates for 44,000 MWH, which is equivalent to the power usage for about 4,500 homes.

    LISF, LLC—a joint venture between BP Solar and Met Life—owns the array and LIPA purchases the electrical output, distributes it, and sells it to customers. BP Solar has announced its intention to exit the solar energy business and we expect it to sell its share to another party, but this would not affect operations or agreements with Brookhaven and the U.S. Department of Energy (DOE). While the Laboratory doesn’t get any electricity from the LISF, it does get large amounts of data from operations. The Lab will get both electricity and research data from the Northeast Solar Energy Research Center (NSERC) being developed on site. By hosting both arrays here, the Lab has positioned itself at the forefront of new research to help develop real-world solar energy technologies.”

    See the full and very enlightening article here.

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

    ScienceSprings is powered by MAINGEAR computers

Compose new post
Next post/Next comment
Previous post/Previous comment
Show/Hide comments
Go to top
Go to login
Show/Hide help
shift + esc

Get every new post delivered to your Inbox.

Join 475 other followers

%d bloggers like this: