Sharp's LR0GC02 Solar Panel module has proved popular in Japan, where phones can now be recharged by just leaving them in the sun.
That technology has now gone global, as Sharp announces that its solar panel will be available across the world to device manufacturers. The company claims that it's the industry's thinnest, at just 0.8mm - the width of eight human hairs. Solar phones have been available in the UK before, but not with a panel that thin.
The cells on the panel will deliver up to 300 mW of juice for your handset, and although they won't replace a traditional battery, they could contribute to increased life of the device. That could be handy both for top-end smartphones with high power requirements, and handsets for the developing world, where mains power isn't widely available.
Tuesday, May 26, 2009
Will global warming benefit starfish
Increasing temperatures and carbon dioxide levels in the world’s oceans may actually speed the growth of starfish, according to research published this week in the Proceedings of the National Academy of Sciences. The results contrast with previous findings of global warming’s negative effects on the five-armed fish’s relatives.
“Mollusks, bivalves, clams and mussels respond negatively to increased carbon dioxide,” says Rebecca Gooding, a doctoral student in zoology at the University of British Columbia and lead author of the paper. On the other hand, she says, compared to their invertebrate cousins, “starfish are growing faster, getting bigger faster, and they’re eating more.”
The starfish’s saving grace, according to Gooding, is that it wears less armor than most other marine invertebrates. (One exception is soft-bodied animals like the sea anemone.) Oceans absorb about half the carbon dioxide humans release into the atmosphere, resulting in more acidic water. Many sea creatures suffer as lowered pH dissolves their calcified shells.
But the effect is not universal. “We need to be careful predicting how species are going to respond to climate change just based on which species they are related to,” says Gooding. “It’s very complex. We actually know very little.”
The researchers put starfish into tanks with carbon dioxide levels and temperatures ranging within current and future levels predicted by the Intergovernmental Panel on Climate Change. In water that contained a relatively high level of carbon dioxide, the sea star, Pisaster ochraceus, grew 67 percent more than its counterparts in tanks set at lower concentrations. An increase of three degrees Celsius (about 5.4 degrees Fahrenheit) boosted relative growth by 110 percent.
Of course, good news for one species doesn’t always apply to an entire underwater ecosystem. Starfish feed on smaller invertebrates, including species not found to do as well under changing ocean conditions.
The mismatch may have a dangerous downside. “This species of sea star just chows down on mussels,” says Gooding. “We expect mussels to grow smaller with rising carbon dioxide since they are stuck in a shell.” The starfish’s dependence on something with shrinking shells makes Gooding wary: “I think mussels are in trouble.”
“Mollusks, bivalves, clams and mussels respond negatively to increased carbon dioxide,” says Rebecca Gooding, a doctoral student in zoology at the University of British Columbia and lead author of the paper. On the other hand, she says, compared to their invertebrate cousins, “starfish are growing faster, getting bigger faster, and they’re eating more.”
The starfish’s saving grace, according to Gooding, is that it wears less armor than most other marine invertebrates. (One exception is soft-bodied animals like the sea anemone.) Oceans absorb about half the carbon dioxide humans release into the atmosphere, resulting in more acidic water. Many sea creatures suffer as lowered pH dissolves their calcified shells.
But the effect is not universal. “We need to be careful predicting how species are going to respond to climate change just based on which species they are related to,” says Gooding. “It’s very complex. We actually know very little.”
The researchers put starfish into tanks with carbon dioxide levels and temperatures ranging within current and future levels predicted by the Intergovernmental Panel on Climate Change. In water that contained a relatively high level of carbon dioxide, the sea star, Pisaster ochraceus, grew 67 percent more than its counterparts in tanks set at lower concentrations. An increase of three degrees Celsius (about 5.4 degrees Fahrenheit) boosted relative growth by 110 percent.
Of course, good news for one species doesn’t always apply to an entire underwater ecosystem. Starfish feed on smaller invertebrates, including species not found to do as well under changing ocean conditions.
The mismatch may have a dangerous downside. “This species of sea star just chows down on mussels,” says Gooding. “We expect mussels to grow smaller with rising carbon dioxide since they are stuck in a shell.” The starfish’s dependence on something with shrinking shells makes Gooding wary: “I think mussels are in trouble.”
A Photovoltaic Cell Lesson
Photovoltaic energy is the conversion of sunlight into electricity. A photovoltaic cell, commonly called a solar cell or PV, is the technology used to convert solar energy directly into electrical power. A photovoltaic cell is a nonmechanical device usually made from silicon alloys.
unlight is composed of photons, or particles of solar energy. These photons contain various amounts of energy corresponding to the different wavelengths of the solar spectrum. When photons strike a photovoltaic cell, they may be reflected, pass right through, or be absorbed. Only the absorbed photons provide energy to generate electricity. When enough sunlight (energy) is absorbed by the material (a semiconductor), electrons are dislodged from the material’s atoms. Special treatment of the material surface during manufacturing makes the front surface of the cell more receptive to free electrons, so the electrons naturally migrate to the surface.
When the electrons leave their position, holes are formed. When many electrons, each carrying a negative charge, travel toward the front surface of the cell, the resulting imbalance of charge between the cell’s front and back surfaces creates a voltage potential like the negative and positive terminals of a battery. When the two surfaces are connected through an external load, electricity flows.
The photovoltaic cell is the basic building block of a photovoltaic system. Individual cells can vary in size from about 1 centimeter (1/2 inch) to about 10 centimeter (4 inches) across. However, one cell only produces 1 or 2 watts, which isn’t enough power for most applications. To increase power output, cells are electrically connected into a packaged weather-tight module. Modules can be further connected to form an array. The term array refers to the entire generating plant, whether it is made up of one or several thousand modules. The number of modules connected together in an array depends on the amount of power output needed.
The performance of a photovoltaic array is dependent upon sunlight. Climate conditions (e.g., clouds, fog) have a significant effect on the amount of solar energy received by a photovoltaic array and, in turn, its performance. Most current technology photovoltaic modules are about 10 percent efficient in converting sunlight. Further research is being conducted to raise this efficiency to 20 percent.
The photovoltaic cell was discovered in 1954 by Bell Telephone researchers examining the sensitivity of a properly prepared silicon wafer to sunlight. Beginning in the late 1950s, photovoltaic cells were used to power U.S. space satellites. The success of PV in space generated commercial applications for this technology. The simplest photovoltaic systems power many of the small calculators and wrist watches used everyday. More complicated systems provide electricity to pump water, power communications equipment, and even provide electricity to our homes.
Some advantages of photovoltaic systems are:
1. Conversion from sunlight to electricity is direct, so that bulky mechanical generator systems are unnecessary.
2. PV arrays can be installed quickly and in any size required or allowed.
3. The environmental impact is minimal, requiring no water for system cooling and generating no by-products.
Photovoltaic cells, like batteries, generate direct current DC-which is generally used for small loads (electronic equipment). When DC from photovoltaic cells is used for commercial applications or sold to electric utilities using the electric grid, it must be converted to alternating current AC-using inverters, solid state devices that convert DC power to AC.
Historically, PV has been used at remote sites to provide electricity. In the future PV arrays may be located at sites that are also connected to the electric grid enhancing the reliability of the distribution system.
unlight is composed of photons, or particles of solar energy. These photons contain various amounts of energy corresponding to the different wavelengths of the solar spectrum. When photons strike a photovoltaic cell, they may be reflected, pass right through, or be absorbed. Only the absorbed photons provide energy to generate electricity. When enough sunlight (energy) is absorbed by the material (a semiconductor), electrons are dislodged from the material’s atoms. Special treatment of the material surface during manufacturing makes the front surface of the cell more receptive to free electrons, so the electrons naturally migrate to the surface.
When the electrons leave their position, holes are formed. When many electrons, each carrying a negative charge, travel toward the front surface of the cell, the resulting imbalance of charge between the cell’s front and back surfaces creates a voltage potential like the negative and positive terminals of a battery. When the two surfaces are connected through an external load, electricity flows.
The photovoltaic cell is the basic building block of a photovoltaic system. Individual cells can vary in size from about 1 centimeter (1/2 inch) to about 10 centimeter (4 inches) across. However, one cell only produces 1 or 2 watts, which isn’t enough power for most applications. To increase power output, cells are electrically connected into a packaged weather-tight module. Modules can be further connected to form an array. The term array refers to the entire generating plant, whether it is made up of one or several thousand modules. The number of modules connected together in an array depends on the amount of power output needed.
The performance of a photovoltaic array is dependent upon sunlight. Climate conditions (e.g., clouds, fog) have a significant effect on the amount of solar energy received by a photovoltaic array and, in turn, its performance. Most current technology photovoltaic modules are about 10 percent efficient in converting sunlight. Further research is being conducted to raise this efficiency to 20 percent.
The photovoltaic cell was discovered in 1954 by Bell Telephone researchers examining the sensitivity of a properly prepared silicon wafer to sunlight. Beginning in the late 1950s, photovoltaic cells were used to power U.S. space satellites. The success of PV in space generated commercial applications for this technology. The simplest photovoltaic systems power many of the small calculators and wrist watches used everyday. More complicated systems provide electricity to pump water, power communications equipment, and even provide electricity to our homes.
Some advantages of photovoltaic systems are:
1. Conversion from sunlight to electricity is direct, so that bulky mechanical generator systems are unnecessary.
2. PV arrays can be installed quickly and in any size required or allowed.
3. The environmental impact is minimal, requiring no water for system cooling and generating no by-products.
Photovoltaic cells, like batteries, generate direct current DC-which is generally used for small loads (electronic equipment). When DC from photovoltaic cells is used for commercial applications or sold to electric utilities using the electric grid, it must be converted to alternating current AC-using inverters, solid state devices that convert DC power to AC.
Historically, PV has been used at remote sites to provide electricity. In the future PV arrays may be located at sites that are also connected to the electric grid enhancing the reliability of the distribution system.
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