David Kirkpatrick

August 17, 2010

Nanotech and solar efficiency

Nanotechnology and solar energy get a lot of virtual ink around here, and I always enjoy getting the chance to blog about both topics in the same post. This study finds that incorporating quantum dots in photovoltaic solar cells through nanoscience should both increase the efficiency of the cells and reduce their cost. A win-win all the way around.

From the link:

As the fastest growing energy technology in the world, solar energy continues to account for more and more of the world’s energy supply. Currently, most commercial photovoltaic power comes from bulk semiconductor materials. But in the past few years, scientists have been investigating how semiconductor nanostructures can increase the efficiency of solar cells and the newer field of solar fuels.

Although there has been some controversy about just how much nanoscience can improve solar cells, a recent overview of this research by Arthur Nozik, a researcher at the National Renewable Energy Laboratory (NREL) and professor at the University of Colorado, shows that semiconductor nanostructures have significant potential for converting solar energy into electricity


August 9, 2010

A meeting of the photonic minds

Experts from three major photonic fields — solar photovoltaics, infrared (IR) photovoltaics and light emitting diode (LED) — met at the 2010 International Symposium on Optoelectronic Materials and Devices held on July 12 and 13, 2010, in Chicago. The conference was put together by the Quantum-functional Semiconductor Research Center of Dongguk University, the Microphysics Laboratory of the University of Illinois at Chicago (UIC) and Sivananthan Laboratories Inc. The symposium gave photonics leaders the opportunity to get together and discuss the current and future state of the industry and its materials and devices.

About the conference, Dr. Chris Grein, Professor of Physics and Director of Graduate Studies at the University of Illinois at Chicago, said, “The fields of solar and infrared photovoltaics and light emitting diodes have many common technical elements yet few conferences bring together experts from all three. One of the goals of the symposium was to facilitate the cross-pollination of many ideas that will benefit these technologies.”

The entire photonic space is rapidly evolving and conferences that put the different disciplines together can spur innovation from unseen sources. A material that imrpoves LED lighting could possibly improve solar cells, or a production technique lowering the cost of solar photovoltaics might also be applicable to IR photovoltaics. Another benefit of this meeting is it puts industry leaders, top researchers, students and other members of this business sector together in one place for a couple of days to speculate and share ideas.

Symposium topics included:

  • thin film solar cells
  • very high efficiency tandem solar cells
  • heteroepitaxial growth
  • antimonide- and HgCdTe-based infrared sensors
  • ZnO nanorods
  • The featured speakers were Dr. Martha Symko Davies of the National Renewable Energy Laboratory and Mr. Minh Le of the Solar Energy Technologies Program at the U.S. Department of Energy. This year’s conference was seventh in an ongoing series

    May 27, 2010

    Renewable power and the US electric grid

    Seems like a bit more compatible than once thought. At least for the western power grid.

    From the link:

    More than a third of the electricity in the western United States could come from wind and solar power without installing significant amounts of backup power. And most of this expansion of renewable energy could be done without installing new interstate transmission lines, according to a new study from the National Renewable Energy Laboratory (NREL) in Golden, CO. But the study says increasing the amount of renewables on the grid will require smart planning and cooperation between utilities.

    The NREL findings provide a strong counterargument to the idea that the existing power grid is insufficient to handle increasing amounts of renewable power. As California and other states require utilities to use renewable sources for significant fractions of their electricity, some experts have warned that measures to account for the variability of wind and solar power could be costly. At the extreme, they speculated, every megawatt of wind installed could require a megawatt of readily available conventional power in case the wind stopped blowing. But the NREL findings, like other recent studies, suggest that the costs could be minimal, especially in the West.

    “The studies are showing the costs are a lot lower than what people thought they were going to be,” says Daniel Brooks, project manager for power delivery and utilization at the Electric Power Research Institute. Even if wind farms had to pay for the necessary grid upgrades and backup power themselves, they could still sell electricity at competitive rates, he says.

    April 2, 2010

    Black silicon bringing down the cost of efficient solar

    Filed under: Science — Tags: , , , , — David Kirkpatrick @ 7:03 pm

    The latest news in one of the two areas — cost in this case — solar needs to continue to see improvement for widespread use.

    From the link:

    A simple chemical treatment could replace expensive antireflective solar cell coatings, bringing down the cost of crystalline silicon panels. The treatment, a one-step dip in a chemical bath, creates a highly antireflective layer of black silicon on the surface of silicon wafers, and it would cost just pennies per watt, say researchers at the National Renewable Energy Laboratory (NREL). They’ve used it to create black silicon solar cells that match the efficiency of conventional silicon cells on the market.

    Solar goes black: These two solar cells were fabricated on a silicon wafer treated to create an antireflective black silicon surface. The silvery areas around the cells are a different color because the highly absorbent black layer has been etched away.
    Credit: Hao-Chih Yuan

    November 5, 2009

    China dominating solar manufacturing

    If you follow the solar cell industry at all that fact should be very readily apparent. The Chinese government has put great emphasis o0n and money into solar. One major advantage Chinese firms have over U.S. and European competitors that’s not going away any time soon is labor costs.

    From the link:

    Solar companies presenting business plans to investors at a National Renewable Energy Laboratory (NREL) conference this week devoted particular attention to how they hope to compete with Chinese manufacturers. The audience at the NREL Industry Growth Forum in Denver consisted largely of venture capitalists and partners from private equity firms.

    Stellaris, a company that assembles solar modules in Lowell, MA, has already received $6.1 million in funding to develop techniques for packaging silicon and thin-film cells. The company, represented at the conference by CEO James Paull, is seeking further financing in 2010.

    November 14, 2008

    Oak Ridge National Laboratory media tips for November

    The release:

    Story tips — Oak Ridge National Laboratory November 2008

    ENERGY — Powering the Big Apple . . .

    High temperature superconductor (HTS) technology developed at Oak Ridge National Laboratory is being used in a $39 million project to boost and secure Manhattan’s power grid. Project HYDRA, partially funded by the U.S. Department of Homeland Security Science and Technology Directorate, seeks to install and field test HTS cable in New York City’s electrical power grid by 2010. ORNL helps design and test the cable which will boost power delivery 30 percent; increase reliability and security; and limit fault currents caused by tree branches, lightning, and other interruptions that hamper the nation’s electric grid. Industrial partners include American Superconductor Corp., which has shipped more than 56,000 feet of wire for the project; Consolidated Edison Co., which operates Manhattan’s power delivery network; and cable manufacturer Ultera, a joint venture between Southwire Co. and nkt cables.

    ENERGY — A DST bonus . . .

    Extending Daylight Saving Time by four weeks last year reduced U.S. energy consumption by 17 trillion British thermal units, or the equivalent of enough energy to power 100,000 households for a year. That’s according to a report to Congress from the U.S. Department of Energy by researchers at Oak Ridge National Laboratory, Pacific Northwest National Laboratory and National Renewable Energy Laboratory. Researchers sought to quantify the savings resulting from the Energy Policy Act of 2005, which extended the duration of Daylight Saving Time. The extension went into effect in March 2007. The study found that electricity consumption in 2007 decreased by an average of 0.5 percent per day during the extra four weeks, which adds up to 1.3 billion kilowatt hours. Savings in northern regions were greater than in the south, which may be attributable to increased air-conditioning usage. The work is funded by DOE’s Office of Energy Efficiency and Renewable Energy. See the report at: http://www.eere.energy.gov/ba/pba/pdfs/epact_sec_110_edst_report_to_congress_2008.pdf

    CLIMATE — Mapping change . . .

    Maps showing possible regional impacts of climate change in the Dominican Republic could play a role in setting policy there and beyond. The maps, generated by a group of researchers at Oak Ridge National Laboratory, will be used for climate change policy discussions and published in a future issue of Foreign Policy, a publication widely read by international policy makers. Projected increased temperatures are just one of the extreme regional stresses considered in the comprehensive ORNL study captured in a series of maps that focus on resource scarcity, extreme events and other impacts of climate and population change. The overall study was led by Auroop Ganguly while the maps for the Dominican Republic were primarily generated by Esther Parish with help from Karsten Steinhaeuser, all of the Geographical Information Science and Technology Group. The research was funded by a grant to ORNL from the Institute for a Secure and Sustainable Environment at the University of Tennessee. Foreign Policy magazine is a non-partisan publication recently acquired by the Washington Post Co. from the Carnegie Endowment for International Peace.

    SENSORS — Right on target . . .

    Keeping track of weapons at nuclear facilities and other installations could get a lot easier with a technology developed by researchers at Oak Ridge National Laboratory and Visible Assets of New Hampshire. The technology, which uses low-frequency magnetic waves to transmit signals from tags installed in a pistol’s grips, solves a huge problem caused by human error during the inventory process. Future system enhancements will make it possible to count the number of shots fired, eliminating any guesswork about when a weapon needs to be serviced or replaced. A team led by Chris Pickett of ORNL’s Global Nuclear Security Technology Division developed the system software and completed the system integration. The team also conducted operational tests and is working with DOE armorers to complete rigorous tests to evaluate the sensor’s performance, durability and security. Those tests will soon be complete, which will clear the path for Department of Energy facilities to purchase the equipment from Sig Sauer, which licensed the technology. Funding was provided by DOE’s Office of Health, Safety and Security.

    September 30, 2008

    Most efficient solar cells to date

    From KurzweilAI.net — This is yet another in a long string of solar breakthroughs. The most efficient photovoltaic cells yet, converting almost 50% of harvested light into electricity. Kudos to the US Department of Energy’s National Renewable Energy Laboratory.

    NREL Solar Cell Sets World Efficiency Record at 40.8 Percent
    ElectricalEngineer.com, Sep. 29, 2008Scientists at the U.S. Department of Energy‘s National Renewable EnergyLaboratory (NREL) have set a world record in solar cell efficiency with a photovoltaic device that converts 40.8 percent of the light that hits it into electricity.

    The new design uses compositions of gallium indium phosphide and gallium indium arsenide to split the solar spectrum into three equal parts that are absorbed by each of the cell‘s three junctions for higher potential efficiencies.

     
    Read Original Article>>

    September 12, 2008

    A great solar idea

    Integrating solar cells into roofing materials is a great solar power idea on many levels.

    From the Technology Review article:

    In an effort to promote the adoption of solar technology, United Solar Ovonic of Auburn Hills, MI, has teamed with a major roofing company to create a metal roof system that generates electricity from sunlight. The partnership offers seven different prefabricated systems, ranging in capacity from 3 to 120 kilowatts. Tests show that the solar roof panels are rugged and can withstand winds in excess of 160 miles per hour.

    In addition to being more aesthetically pleasing than bulky rooftop-mounted panels, solar roofing materials can cut the cost of household solar installations by doing double duty, generating electricity while protecting buildings from the elements. “Ultimately, if you can use one product to do two things, you can save a lot of money,” says Cecile Warner, principal engineer at the National Renewable Energy Laboratory’s National Center for Photovoltaics, in Golden, CO.

    Building-integrated photovoltaics (BIPV) have been around since the late 1980s, Warner says, but only lately have they begun to see some success with large commercial and residential developments. Recent advances in flexible thin-film photovoltaic materials–such as those sold by United Solar–are allowing manufacturers to more easily integrate photovoltaics directly into the roofs and facades of buildings.

    The solar system shown here (darker panels) integrates thin-film solar modules directly into a metal roof. Such systems offer cost savings in labor and materials and blend well with buildings’ designs.

    Seamless solar: The solar system shown here (darker panels) integrates thin-film solar modules directly into a metal roof. Such systems offer cost savings in labor and materials and blend well with buildings’ designs.

    August 13, 2008

    Major solar breakthrough at NREL

    This is exciting news for alternative energy.

    From the PhysOrg.com link:

    Scientists at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) have set a world record in solar cell efficiency with a photovoltaic device that converts 40.8 percent of the light that hits it into electricity. This is the highest confirmed efficiency of any photovoltaic device to date.

    The inverted metamorphic triple-junction solar cell was designed, fabricated and independently measured at NREL. The 40.8 percent efficiency was measured under concentrated light of 326 suns. One sun is about the amount of light that typically hits Earth on a sunny day. The new cell is a natural candidate for the space satellite market and for terrestrial concentrated photovoltaic arrays, which use lenses or mirrors to focus sunlight onto the solar cells.