Using minute graphite particles 1000 times smaller than the width of a human hair, mechanical engineers at Arizona State University hope to boost the efficiency and profitability of solar power plants.

Nanowires and Nanocrystals for Nanotechnology Video. An overview on the research about how nanomaterials impact the critical applications in faster transistors, smaller nonvolatile memory devices, efficient solar energy conversion, high-energy battery and nanobiotechnology.

Photovoltaic (PV) solar panels are popping up more and more on rooftops, but they’re not necessarily the best solar power solution. “The big limitation of PV panels is that they can use only a fraction of the sunlight that hits them, and the rest just turns into heat, which actually hurts the performance of the panels,” explains Robert Taylor, a graduate student in mechanical engineering at Arizona State University.

Graphite Structure. Click on this image to view an interactive Jmol version of this model.

An alternative that can make use of all of the sunlight, including light PVs can’t use, is the solar thermal collector. The purpose of these collectors — which take the form of dishes, panels, evacuated tubes, towers, and more — is to collect heat that can then be used to boil water to make steam, for example, which drives a turbine to create electricity.
To further increase the efficiency of solar collectors, Taylor and his colleagues have mixed nanoparticles — particles a billionth of a meter in size — into the heat-transfer oils normally used in solar thermal power plants. The researchers chose graphite nanoparticles, in part because they are black and therefore absorb light very well, making them efficient heat collectors. In laboratory tests with small dish collectors, Taylor and his colleagues found that nanoparticles increased heat-collection efficiency by up to 10 percent. “We estimate that this could mean up to $3.5 million dollars per year more revenue for a 100 megawatt solar power plant,” he says.

What’s more, Taylor adds, graphite nanoparticles “are cheap” — less than $1 per gram — but with 100 grams of nanoparticles providing the same heat-collecting surface area as an entire football field. “It might also be possible to filter out nanoparticles of soot, which have similar absorbing potential, from coal power plants for use in solar systems,” he says. “I think that idea is particularly attractive: using a pollutant to harvest clean, green solar energy.”

Source: the Journal of Renewable and Sustainable Energy.

The U.S. Department of Energy aims to make electricity from the sun cheaper than that from burning coal or natural gas.
NATIONAL HARBOR, Md.—Silicon translates sunshine into electricity—and Earth receives enough sunshine in a daylight hour to supply all of humanity’s energy needs for a year. But despite being as common as sand, photovoltaic panels made from silicon—or any of a host of other semiconducting materials—are not cheap, especially when compared with the cost of electricity produced by burning coal or natural gas. The U.S. Department of Energy (DoE) aims to change that by bringing down the cost of solar electricity via a new program dubbed “SunShot,” an homage to President John Kennedy’s “moon shot” pledge in 1961.

The U.S. Department of Energy aims to make electricity from the sun as cheap as that from burning coal or natural gas – by 2017.
Image: Dennis Schroeder, NREL Staff Photographer.

“If you can get solar electricity down at [$1 per watt], and it scales without subsidies, gosh, I think that’s pretty good for the climate,” notes Arun Majumdar, director of the Advanced Research Projects Agency–Energy (ARPA–e), the DoE’s high-risk research effort. “With SunShot, the goal is to reduce the cost of solar to [$1 per watt] in the next six years.”

As it stands, melting silicon or depositing thin layers of copper indium gallium selenide, then manufacturing photovoltaic modules and installing them on rooftops or in large arrays in the desert, can cost as much as $10 per watt. And whereas some technologies can deliver modules for roughly $1 per watt, installation at least doubles that.

“We are making solar for the masses…to get to [a] cost point that is viable,” said Bruce Sohn, president of Columbus, Ohio–based First Solar, the world’s largest thin-film photovoltaic manufacturer, which claims it can produce its modules for less than $1 per watt, on a panel at ARPA–e’s second annual summit on March 1. “We are looking to make something that can compete head to head with fossil fuels over the long term.”

As part of the new SunShot initiative, DoE committed some $27 million to fund novel methods for producing solar cells and their components—like 1366 Technology’s effort to grow pure silicon wafers directly rather than hewing them from long ingots of the material or Solexant’s effort to build thin-film solar cells from semiconducting materials that are neither toxic nor rare. The goal is to produce solar modules at roughly 50 cents per watt with attendant hardware and installation costing the same amount. To reach that target the photovoltaic cells will have to convert at least 20 percent of the sunlight that shines on it into electricity and cost only 25 cents per watt by 2017. “The future of the U.S. depends on three securities: national, economic and environmental. The foundation of all of this is innovations in energy technology,” Majumdar said in his own speech to the summit. “The future is still up for grabs. How do we win the future? Invent affordable clean technology. Make them locally, sell them globally.”

Of course, harvesting the sun’s power is not limited to photovoltaic panels. The DoE push also will incorporate efforts to create solar-thermal power plants that can store the heat of the sun for 12 to 17 hours by 2020, along with attempting to address some of the issues surrounding permitting, inspection and connection of solar systems to the electricity grid. “We want change, we want innovation, we want to overthrow the old energy order,” said former California governor Arnold Schwarzenegger in a summit keynote address. “We want a new era of energy and a new era of American competitiveness.”

Former California Governor Arnold Schwarzenegger addresses the 2011 APRA-E Technology and Innovation Summit on California’s role in clean energy.

Already, electricity from the sun costs roughly the same as that generated from burning fossil fuels in places like Hawaii, which remains the only state to rely on imported oil for the bulk of its power. And solar power represents the fastest-growing sector of electricity generation. U.S. solar production in 2010 increased by nearly one gigawatt (billion watts), although that represents roughly the amount of electricity one nuclear power plant can produce. But even at that pace of adoption—spurred by both federal and state government largesse—solar still produces less than 1 percent of all U.S. electricity. And in 2035, by which time the DoE’s Energy Information Administration (EIA) predicts that solar will have grown fastest among all energy resources (increasing sevenfold), all renewables put together, solar included, will only provide 14 percent of U.S. electricity.

The EIA has often been wrong in such long-term forecasts, but competing with natural gas—newly cheap thanks to the vast resources tapped by fracking in the eastern U.S.’s Marcellus Shale Formation—may prove difficult, even with SunShot. “Natural gas has low capital cost, higher fuel cost but overall lowest costs,” noted EIA Administrator Richard Newell at the ARPA–e conference. “There are significantly higher costs for other power sources.”

Yet, even at a higher price, solar can offer benefits, which is why Duke Energy has invested $50 million putting solar arrays on the roofs of grocery stores and some of its other large customers. “Distributed solar can be thought of as a distributed resource, a multiple value resource,” Duke Chief Technology Officer David Mohler told ARPA–e attendees. “The proper comparison for that is not the cost of a bulk power system, it’s the cost and benefit of having an embedded resource.”

And flexible solar cells in sheets have already found novel applications powering the telecommunications and other electronic equipment of U.S. Marine units deployed in Afghanistan. Small-scale solar is also booming in places such as Kenya that do not have an electricity grid for charging cell phones or batteries that power lights at night. “We will need every energy resource we can lay our hands on,” said Kurt Yeager, executive director of the Galvin Electricity Initiative, an effort to develop the smart grid in the U.S. “There are two billion people in the world without access to electricity. Security means giving them energy.”

Of course, the DoE has already invested some $1 billion in solar energy research since the turn of the century, funding efforts to develop “black” silicon or cells employing quantum dots. “If renewables are cost-competitive with fossil fuels then it’s a very, very different world,” Secretary of Energy Steven Chu said at the ARPA–e summit.

Secretary for the US Department of Energy, Steven Chu, discusses the big picture of how the United States uses Energy and why innovation in clean technology is the key to Winning the Future.

Yet, despite inventing the technology in the 1950s and more than 30 years of government support, the U.S. share of the global market for photovoltaic modules is down from more than 40 percent in 1995 to just 6 percent in 2011. China’s Jiangsu Province alone—home to Suntech Power, the world’s largest maker of photovoltaic panels—has begun investing more than $152 million a year in solar technology since 2009.

“Just because we lost the lead doesn’t mean we can’t get it back,” Chu said. “We still have the opportunity to lead the world in clean energy…but time is running out.”

Article by By David Biello.
Source: scientificamerican.com.

Greendix, the company that makes these nifty leaf-shaped solar panels has captured our attention yet again with something even cooler – the world’s first solar powered soccer ball! The Taiwan-based company unveiled photos of the ball, which looks just like a regular soccer ball except that the iconic black pentagonal patches have been replaced with solar cells, giving it an eye-catching, prismatic look. Even more interestingly, the company is developing the ball with motion-sensing technology in hopes that it will allow visually impaired people to play with it!

World’s First Solar Powered Soccer Ball at Greendix. Image by Greendix.

The solar powered ball’s panels power built-in motion sensors and an audio device which could potentially enable visually impaired people to play soccer/football – each time the prototype is kicked, it emits a tracking sound.

While we think the direction Greendix is moving with the ball is innovative, we’re interested to see if they’re also planning on making it so the ball can store energy to be used at a later time like some other soccer balls can. Such technology can be used by kids in developing nations as a safer alternative to kerosene lamps to power lighting so that they can study and read at night.

“The main goal of this project was to prove that solar panels can be integrated into any object that we interact with on a daily basis and to push the limits of what is possible with solar panels,” explained Joseph Lin from Greendix. No word yet on when the ball will be available for sale, but how great would it be to see these being used at the next World Cup?

Source: greenmuze.com.

Looking for some alternatives to the typical holiday electric fare this year? What is a better Christmas present that a reduced energy bill? While some of us get creative with LED solar powered Christmas string lights, an aquarium in Japan has resolved this problem in by powering a Christmas tree with an electric eel!

See video below:

The Enoshima Aquarium in Kamakura (south of Tokyo) utilizes the eels ability to generate electricity when moving. It effectively powers a two meter Christmas tree. While the power generated isn’t enough to provide consistent light, it is strong enough to allow intermittent flashing.

See video below:

To further add to its eco-friendliness, the aquarium, have also added a robotic Santa Claus powered by human muscle. When visitors to the aquarium step on a pad, it generates electricity.

While the idea of using eel to promote eco-awareness is certainly a good one, you should probably stick with something like solar powered Christmas lights to create our own green Christmas. The decorative outdoor lights are an ideal addition to any home, but with an energy efficient twist you won’t feel guilty when they turn on night after night.

Solar String Lights are ideal to light up your trees, rooftops, doorways, pathways, windows and porches. No wiring. Fast and easy to install. Energy saving, recharged by solar panel under sunlight. Lights turn on automatically when dark. Safe, corrosion/water resistant.

What is the life span of solar lights?

Many times the question pops up regarding the life span of solar powered lights. How does one ensure the best performance and prolong the life of solar lights? After a while, you might notice that your solar lights are not as bright as when you first bought them. And without knowing the basics of solar lights, you may become confused about what exactly happened. Could it be that your solar lights got old and need to be recycled or is there something that you just need to know about the maintenance of your solar powered products?

Solar lights need four essential components to function:

1. A rechargeable battery to store the power generated by the energy from the sun.

2. A small photovoltaic cell or solar array that captures sunlight during the day and converts it into electrical energy. The solar array is usually built right into the light fixture. Some light designs have separate solar arrays connected by a thin wire allowing the light to be located in a shady area while the solar array itself is placed in a bright, sunny location.

3. A “charge controller” to ensure the batteries don’t get overcharged in bright sunlight as well as to monitor the amount of light in the surrounding area and turn the LED (light emitting diode) light on and off.

4. An LED (or a series of LEDs) which provides the light.

10-Pack NiCd AA700mAh 1.2V Rechargeable Batteries at http://www.yoursolarlink.com.

Image by Your Solar Link.

Rechargeable Solar Light Batteries are the major cause of failure in solar garden lights (5 main reasons why your solar lights are not performing as well as new.)

Rechargeable solar batteries will self-discharge which means that over time the batteries will discharge to a point where they no longer work.

It is important to ensure you charge your solar lights at least every three (3) months to ensure the battery stays in good shape and lasts its life span, generally 1-2 years.

Replace your old batteries when they run their life cycle.

When you purchase your solar lights, the rechargeable batteries are often already included in the fixture. After 1-2 years (or a matter of months in some cases) it is quite normal to see their performance decline. Once you notice that the lighting time is considerably diminishing and the lights are not as bright as before, it’s probably time to replace your rechargeable solar garden light batteries.

Another reason of reduced lighting time and brightness can also be that the solar light batteries are not charging correctly.

For the best charging performances the solar panel needs to be cleaned on a regular basis. Dust and other accumulated residues can considerably affect the charging procedure. They form a coating layer on the solar panel and block the sunlight.

10-Pack NiCd AA600mAh 1.2V Rechargeable Batteries at http://www.yoursolarlink.com.

Image by Your Solar Link.

An easy way to check if the rechargeable batteries are dead is to test them by briefly replacing them with regular batteries, just long enough to check if the light is working. If you are testing the solar light during the day, don’t forget to cover it, or place the light in a darkened room. This will allow the photocell to trigger the light to its “on” position. If the solar light turns on with normal batteries it means that the rechargeable batteries are faulty and you will need to buy a new set.

Important: don’t forget to pay particular attention to the location of the solar lights.

Batteries will not charge properly if the solar panel is in the shade, they rely on the energy of the sun to charge.

There is another simple test you can do before replacing the solar light rechargeable batteries. Place your solar lights under direct sunshine for a day or two and see what happens. If, after this duration, the illumination time is back to normal, it means that the solar panel was not getting enough light from the sun. Commonly, solar lights should be in direct sunlight for at least 4 hours a day to adequately charge the rechargeable batteries.

If you store your solar lights for long periods of time, take the batteries out!

When you had to store your garden solar lights for a long period of time (during winter months, for example), did you take out the batteries? If you did, your solar light batteries will have a longer life span.

10-Pack NiMH AA1000mAh 1.2V Rechargeable Batteries at http://www.yoursolarlink.com.

Image by Your Solar Link.

Replacing solar light batteries is not a difficult task.

All you have to do is to locate the solar light battery cover, remove it, take out the defective batteries and replace them with new ones. If no battery cover can be found, the solar light needs to be taken apart, usually with one or two screws. On most models you’ll find the screws on the top or bottom of the light. Once the unit is open you’ll have access to the batteries.

Types of rechargeable batteries.

Most solar garden lights need between 1 to 4 batteries to work. 2 types of batteries are usually used in garden solar lights: AA size – NiCad(Nickel Cadmium) 1.2 V / 500 to 900mA, and AA size – NiMH (Nickel Metal Hydride) 1.2 V /1000 to 2000mA.

When it is time to change the solar light rechargeable batteries, the choice of battery also plays an important part in ensuring the enhanced performance of your solar lights.

Nickel-metal hydride batteries (NiMH) will have up to three times more capacity than the same size Nickel-cadmium (NiCd) battery, meaning they are capable of lasting longer and more reliable.

NiMH batteries in your solar lights may cost a little extra but they are more environmentally friendly than NiCd batteries. NiMH batteries are more environmentally friendly because they use a dry liquid, which can be disposed of more easily. They will also withstand greater temperature fluctuations operating in temperatures ranging from -20 to 60 degrees Celsius (-4 to 140F). Ni-MH batteries have a “non-memory effect” which means they will continue to charge on cloudy days. The battery performance will not be diminished by these partial charges, as what can occur with lead acid batteries.

10-Pack NiMH AAA900mAh 1.2V Rechargeable Batteries at http://www.yoursolarlink.com.

Image by Your Solar Link.

Solar light replacement batteries are standard and can be found easily. If you know these solar lights basics, with minimum maintenance effort you will enjoy your solar powered lights for years.