Thursday, June 17, 2010

Here’s a rapid solution to find out how solar panels work.

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What exactly is solar energy ?
Solar energy is radiant energy which is produced by the sun. Every day the sun radiates, or sends out, an enormous volume of energy. The sun radiates more energy in a single second than people have used since the beginning of time!
The energy of the Sun comes from within the sun itself. Like other stars, the sun is really a big ball of gases––mostly hydrogen and helium atoms.
The hydrogen atoms in the sun’s core combine to form helium and generate energy in a process called nuclear fusion.

During nuclear fusion, the sun’s extremely high pressure and temperature cause hydrogen atoms to come apart and their nuclei (the central cores of the atoms) to fuse or combine. Four hydrogen nuclei fuse to become one helium atom. However the helium atom contains less mass compared to four hydrogen atoms that fused. Some matter is lost during nuclear fusion. The lost matter is emitted into space as radiant energy.
It takes millions of years for the energy in the sun’s core to make its way to the solar surface, and somewhat over eight minutes to travel the 93 million miles to earth. The solar energy travels to the earth at a speed of 186,000 miles per second, the speed of light.
Only a small part of the energy radiated from the sun into space strikes the earth, one part in two billion. Yet this volume of energy is enormous. On a daily basis enough energy strikes the united states to supply the nation’s energy needs for one and a half years!

Where does all this energy go?
About 15 percent of the sun’s energy that hits our planet is reflected back into space. Another 30 percent is used to evaporate water, which, lifted in to the atmosphere, produces rainfall. Solar power is also absorbed by plants, the land, and the oceans. The remaining could be used to supply our energy needs.
Who invented solar technology ?
Humans have harnessed solar energy for hundreds of years. As early as the 7th century B.C., people used simple magnifying glasses to concentrate the light of the sun into beams so hot they would cause wood to catch fire. Over a century ago in France, a scientist used heat from a solar collector to create steam to drive a steam engine. In the beginning of this century, scientists and engineers began researching ways to use solar technology in earnest. One important development was a remarkably efficient solar boiler invented by Charles Greeley Abbott, an american astrophysicist, in 1936.

The solar water heater gained popularity at this time in Florida, California, and the Southwest. The industry started in the early 1920s and was in full swing just before World War II. This growth lasted before mid-1950s when low-cost natural gas had become the primary fuel for heating American homes.
People and world governments remained largely indifferent to the possibilities of solar technology until the oil shortages of the1970s. Today, people use solar technology to heat buildings and water and also to generate electricity.
How we use solar power today ?
Solar energy is employed in a variety of ways, of course. There are 2 standard forms of solar power:

* Solar thermal energy collects the sun's warmth through 1 of 2 means: in water or in an anti-freeze (glycol) mixture.

* Solar photovoltaic energy converts the sun's radiation to usable electricity.

Listed below are the five most practical and popular ways that solar energy is used:

1. Small portable solar photovoltaic systems. We see these used everywhere, from calculators to solar garden tools. Portable units can be utilized for everything from RV appliances while single panel systems are used for traffic signs and remote monitoring stations.

2. Solar pool heating. Running water in direct circulation systems via a solar collector is an extremely practical solution to heat water for your pool or hot spa.

3. Thermal glycol energy to heat water. In this method (indirect circulation), glycol is heated by sunshine and the heat is then transferred to water in a hot water tank. This process of collecting the sun's energy is more practical now than ever before. In areas as far north as Edmonton, Alberta, solar thermal to heat water is economically sound. It can pay for itself in three years or less.

4. Integrating solar photovoltaic energy into your home or office power. In most parts on the planet, solar photovoltaics is an economically feasible approach to supplement the power of your home. In Japan, photovoltaics are competitive with other forms of power. In the USA, new incentive programs make this form of solar technology ever more viable in many states. An increasingly popular and practical way of integrating solar energy into the power of your home or business is through the use of building integrated solar photovoltaics.

5. Large independent photovoltaic systems. For those who have enough sun power at your site, you could possibly go off grid. It's also possible to integrate or hybridize your solar energy system with wind power or other forms of renewable energy to stay 'off the grid.'

How can Photovoltaic panels work ?
Silicon is mounted beneath non-reflective glass to create photovoltaic panels. These panels collect photons from the sun, converting them into DC electrical energy. The energy created then flows into an inverter. The inverter transforms the power into basic voltage and AC electrical power.
Photovoltaic cells are prepared with particular materials called semiconductors for example silicon, which is presently the most generally used. When light hits the Photovoltaic cell, a certain share of it is absorbed inside the semiconductor material. This means that the energy of the absorbed light is given to the semiconductor.

The power unfastens the electrons, permitting them to run freely. Photovoltaic cells also have one or more electric fields that act to compel electrons unfastened by light absorption to flow in a specific direction. This flow of electrons is a current, and by introducing metal links on the top and bottom of the -Photovoltaic cell, the current can be drawn to use it externally.
What are the benefits and drawbacks of solar power ?

Solar Pro Arguments:

- Heating our homes with oil or natural gas or using electricity from power plants running with coal and oil is a reason for climate change and climate disruption. Solar power, on the other hand, is clean and environmentally-friendly.

- Solar hot-water heaters require little maintenance, and their initial investment could be recovered within a relatively limited time.

- Solar hot-water heaters can work in almost any climate, even just in very cold ones. You just need to choose the right system for your climate: drainback, thermosyphon, batch-ICS, etc.

- Maintenance costs of solar powered systems are minimal and also the warranties large.

- Financial incentives (USA, Canada, European states…) can reduce the price of the first investment in solar technologies. The U.S. government, for example, offers tax credits for solar systems certified by by the SRCC (Solar Rating and Certification Corporation), which amount to 30 percent of the investment (2009-2016 period).

Solar Cons Arguments:

- The initial investment in Solar Hot water heaters or in Solar PV Electric Systems is greater than that required by conventional electric and gas heaters systems.

- The payback period of solar PV-electric systems is high, as well as those of solar space heating or solar cooling (only the solar warm water heating payback is short or relatively short).

- Solar water heating do not support a direct in conjunction with radiators (including baseboard ones).

- Some air cooling (solar space heating and the solar cooling systems) are costly, and rather untested technologies: solar air conditioning isn't, till now, a really economical option.

- The efficiency of solar powered systems is rather influenced by sunlight resources. It's in colder climates, where heating or electricity needs are higher, that the efficiency is smaller.

About me - Barbara Young writes on
motorhome solar power in her personal hobby blog 12voltsolarpanels.net. Her work is centered on helping people save energy using solar power to reduce CO2 emissions and energy dependency.

Sunday, January 17, 2010

Hexapod robot moves in the right direction by controlling chaos.

Source: Scientific American

Given that robots generally lack muscles, they can't rely on muscle memory (the trick that allows our bodies to become familiar over time with movements such as walking or breathing) to help them more easily complete repetitive tasks. For autonomous robots, this can be a bit of a problem, since they may have to accommodate changing terrain in real time or risk getting stuck or losing their balance.
One way around this is to create a robot that can process information from a variety of sensors positioned near its "legs" and identify different patterns as it moves, a team of researchers report Sunday in Nature Physics. (Scientific American is part of Nature Publishing Group.)
Some scientists rely on small neural circuits called "central pattern generators" (CPG) to create walking robots that are aware of their surroundings. One of the challenges is that the robot typically needs a separate CPG for each leg in order to sense obstacles and take the appropriate action (such as stepping around a chair leg or over a rock).
Bernstein Center for Computational Neuroscience researcher Poramate Manoonpong and Max Planck Institute for Dynamics and Self-Organization researcher Marc Timme are leading a project that has created a six-legged robot with one CPG that can switch gaits depending upon the obstacles it encounters. The robot does this by manipulating the sensor inputs into periodic patterns (rather than chaotic ones) that determine its gait. In the future, the robot will also be equipped with a memory device that will enable it to complete movements even after the sensory input ceases to exist.
© Poramate Manoonpong and Marc Timme, University of Goettingen and Max Planck Institute for Dynamics and Self-Organization

Friday, January 15, 2010

Fleet of High-Tech Robot 'Gliders' to Explore Oceans.

Glider under water. (Credit: Holger v. Neuhoff, IFM-GEOMAR)
Source: ScienceDaily
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ScienceDaily (Jan. 14, 2010) — The Leibniz Institute of Marine Sciences (IFM-GEOMAR) in Kiel, Germany, recently obtained the biggest fleet of so-called gliders in Europe. These instruments can explore the oceans like sailplanes up to a depth of 1000 metres. In doing so they only consume as much energy as a bike light. In the next years up to ten of these high-tech instruments will take measurements to better understand many processes in the oceans. Currently scientists and technicians prepare the devices for their first mission as a 'swarm' in the tropical Atlantic.
They may look like mini-torpedoes, yet exclusively serve peaceful purposes. The payload of the two-metre-long yellow diving robots consists of modern electronics, sensors and high-performance batteries. With these devices the marine scientists can collect selective measurements from the ocean interior while staying ashore themselves. Moreover, the gliders not only transmit the data in real time, but they can be reached by the scientists via satellite telephone and programmed with new mission parameters.
As such the new robots represent an important supplement to previous marine sensor platforms.
"Ten year ago we started to explore the ocean systematically with profiling drifters. Today more than 3000 of these devices constantly provide data from the ocean interior," explains Professor Torsten Kanzow, oceanographer at IFM-GEOMAR. This highly successful programme has one major disadvantage: the pathways of the drifters cannot be controlled.
"The new gliders have no direct motor, either. But with their small wings they move forward like sailplanes under water," says Dr. Gerd Krahmann, a colleague of Professor Kanzow. In a zigzag movement, the glider cycles between a maximum depth of 1000 metres and the sea surface.
"By telephone we can 'talk' to the glider and upload a new course everytime it comes up," explains Krahmann. A glider can carry out autonomous missions for weeks or even months. Every glider is equipped with instruments to measure temperature, salinity, oxygen and chlorophyll content as well as the turbidity of the sea water.
The IFM-GEOMAR has been the first institute in Europe to be committed to the new technology. "We tested different devices and we had to learn the hard way, too," oceanographer Dr. Johannes Karstensen says. "This way we have been able to contribute to the glider development, and now we have gathered knowledge required for successful glider operations," he adds.
Within the context of a special investment IFM-GEOMAR was able to obtain six new gliders adding to a total of nine altogether, which is the biggest fleet of that kind in Europe. Manufacturer of the IFM-GEOMAR-gliders is the Teledyne Webb Research Inc. in the USA.
A very successful mission using a single glider took place between August and October 2009 in the Atlantic Ocean, south of the Cape Verde Islands. The robot carried out measurements along a more than 1000 kilometres long track autonomously, before it was recovered by the German research vessel METEOR. The data collected are accessible online at
http://gliderweb.ifm-geomar.de/html/ifm03_depl05_frame.html.
Now, for the first time the scientists in Kiel prepare a whole fleet of gliders for a concerted mission. After final tests the robots will be released mid-March 2010 at about 60 nautical miles north-east of the Cape Verde Island of Sao Vicente. For two months they will investigate physical and biogeochemical quantities of the Atlantic Ocean around the oceanographic long-term observatory TENATSO.
Goals of the experiment lead jointly by Prof. Torsten Kanzow, Prof. Julie LaRoche (marine biology) and Prof. Arne Körtzinger (marine chemistry) are to get new insights into water circulation and stratification as well as their impact on chemical and biological processes. With the glider swarm the scientists can sample a complete "sea-volume" and not just a single point or a single cross-section in the ocean. The gliders will be remotely controlled from a control centre at the IFM-GEOMAR in Kiel.
"This technology enables us to observe the upper layers of the ocean much more effectively and thus much less expensive than previously," says Prof. Dr. Martin Visbeck, Deputy Director of the IFM-GEOMAR and Head of the research division Ocean Circulation and Climate Dynamics.
Story Source:
Adapted from materials provided by
Leibniz Institute of Marine Sciences (IFM-GEOMAR), via AlphaGalileo.

Thursday, January 14, 2010

Modified Mobile Phone Runs on Coca-Cola.

A modified Nokia cell phone that runs on Coca-Cola could run up to four times longer than a phone with a lithium ion battery. Image credit: Daizi Zheng.
Source: Physorg.com
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Daizi Zheng, a Chinese developer who is currently based in London, has modified a Nokia cell phone to run on Coca-Cola or any other sugary solution.
Zheng says the modified phone can run three or four times longer on a single charge than a phone using a conventional , and can also be fully biodegradable.
As Zheng explains, a sugar-powered phone could potentially offer a much more environmentally friendly power source than lithium ion batteries. The new phone's bio battery, which basically acts as a , uses enzymes as the to generate from carbohydrates.
The phone can run for several hours, and produces water and carbon dioxide as the battery runs down. The phone can then be emptied out and refilled with more Coca-Cola.
Zheng designed the phone as a client project for Nokia, but there's no word on whether the company plans to incorporate the concept into future products.
"It brings a whole new perception to batteries and afternoon tea," Zheng wrote on her project's website.
More information: www.daizizheng.com

Samsung's new flash chips for mobile devices.

Samsung 32GB microSD memory card
Source: Physorg.com
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Samsung Electronics has announced two new flash chip storage devices for mobiles: a removable 32-Gbyte micro SD (secure digital) card and a 64-Gbyte moviNAND flash memory module. Both are based on Samsung's own 30 nanometer class 32-Gbyte NAND flash memory chips, which use lithography technology that allows much more storage in a smaller unit.

The removable SD flash card is only 1 mm thick and 0.7 mm high and will come into production in February. The card comprises a card controller and eight 30-micron thick stacked chips. Samsung says it is the highest capacity microSD ready for production. Users will be able to insert the 32-Gbyte micro SD card into their phone or other device via the built-in micro SD slot.
The 64-Gbyte flash chip is 1.4 mm thick and consists of sixteen stacked chips and a storage controller. This moviNAND embedded memory module has been in commercial production since December last year and will be the first to reach the marketplace. It doubles the memory of current memory modules such as that in the latest Apple
.
Higher capacity devices such as Samsung's new offerings will allow mobile devices such as smartphones and media players to have increased memory, and demand for more memory is expected to increase as the market for mobile devices and the applications they run continues to grow. Executive President of Memory Marketing for Samsung, Dong-Soo Jun, said the new memory solutions will bring the
of computers to mobile devices.
The expected cost of the two new high-density storage devices has not been released.

Self-assembling solar panels a step closer.

The self assembly process made a device of 64,000 parts in 3 minutes. Image: Heiko O. Jacobs
Source: Physorg.com
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Scientists Robert J. Knuesel and Heiko O. Jacobs of the University of Minnesota have developed a way to make tiny solar cells self-assemble.
The researchers had previously been unsuccessful in their attempts to make self-assembling electronic components. In large systems gravity can be used to drive , and in nanoscale systems chemical processes can be used, but between the two scales, in the micrometer range, it is much more difficult.
To overcome the difficulties, Kneusel and Jacobs designed a flexible substrate of a thin layer of copper covered with propylene-terephthalate (PET). Regular depressions the same size as the "chiplets" were etched into the PET layer and then the sheet was dipped into a bath of molten solder, which coated the exposed copper in the etched depressions. Each chiplet consisted of a 20-60 µm silicon cube with one gold face. The silicon sides had a coating of hydrophobic (water-repelling) molecules, while the gold side had a hydrophilic (water-attracting) coating.
When the elements were placed in a container containing oil and water, they neatly arranged themselves in a sheet at the boundary between the liquids, with the gold side pointed down to the water layer. The substrate was then pulled slowly up through the boundary like a conveyor belt, and the elements neatly dropped in place in the depressions as the solder attracted the
side. Accuracy was 98%. The assembly was covered with epoxy to keep the chiplets in place, and then a conducting layer was added.
The device was able to assemble 62,000 elements, each of them thinner than a human hair, in only three minutes. The elimination of a dependency on gravity and sedimentation meant the chiplets could be reduced to below 100 micrometers in size. It was important to limit the assembly time to avoid oxidation of the surfaces, which would reduce surface energies and interfere with self-assembly. The water layer had to be acidic, at pH 2.0, and the temperature had to be kept at 95C to keep the solder molten.
The researchers think they can adapt their method to smaller components and larger assembled devices, and it could be used to cheaply and quickly assemble all kinds of high-quality electronic components on a wide range of flexible or inflexible substrates including plastics, semiconductors and metals. The assemblages could find uses in numerous applications such as , video displays and tiny semiconductors.
The use of this method in solar cell production would reduce the cost considerably since less silicon is needed, and it should also be possible to assemble solar chiplets into transparent, flexible materials, which would extend their range of uses.
The paper is published in the Proceedings of the National Academy of Sciences (PNAS).
More information: Self-assembly of microscopic chiplets at a liquid-liquid-solid interface forming a flexible segmented monocrystalline solar cell, Robert J. Knuesel and Heiko O. Jacobs, PNAS,
DOI:10.1073/pnas.0909482107

No-Sweat Pressure Sensors.

The new pressure sensor works at temperatures of up to 250 degrees Celsius. (Credit: Copyright Fraunhofer IMS)
Source: ScienceDaily
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ScienceDaily (Jan. 13, 2010) — Microelectronic chips used to take pressure readings are very delicate. A new technology has been developed that makes pressure sensors more robust, enabling them to continue operating normally at temperatures up to 250 degrees Celsius.
The drill bit gradually burrows deeper into the earth, working its way through the rock. Meanwhile, dozens of sensors are busily engaged in tasks such as taking pressure readings and evaluating porosity. The conditions they face are extreme, with the sensors being required to withstand high temperatures and pressures as well as shocks and vibrations. The sensors send the data to the surface to help geologists with work such as searching for oil deposits.
Yet there is one major hurdle: on average, the pressure sensors can only withstand temperatures of between 80 and 125 degrees Celsius -- but at great depths the temperature is often significantly higher. The Fraunhofer Institute for Microelectronic Circuits and Systems IMS in Duisburg has come to the rescue, its researchers having developed a pressure sensor system that continues to function normally even at 250 degrees Celsius.
"The pressure sensors consist of two components that are located on a microelectronic chip or wafer," explains Dr. Hoc Khiem Trieu, department head at IMS. "The first component is the sensor itself, and the other component is the EEPROM." This is the element that stores all the readings together with the data required for calibration.
To enable the pressure sensor to function properly even at extremely high temperatures, the developers modified the wafer. While normal wafers tend to be made of monocrystalline silicon, the researchers chose silicon oxide for this application. "The additional oxide layer provides better electrical insulation," Trieu continues. "It prevents the leakage current that typically occurs at very high temperatures, which is the principal reason that conventional sensors fail when they reach a certain temperature."
The oxide layer enabled the researchers to improve the insulation of the memory component by three to four orders of magnitude. In theory, this should enable the pressure sensors to withstand temperatures of up to 350 degrees Celsius -- the researchers have provided practical proof of stability up to 250 degrees and are planning to conduct further studies at higher temperatures. In addition, the researchers are analyzing the prototypes of the pressure sensors in endurance tests.
There is a broad range of potential applications, with engineers hoping to use the high-temperature pressure sensors not only in the petrochemical environment, but also in automobile engines and geothermal applications.
Story Source:
Adapted from materials provided by
Fraunhofer-Gesellschaft.

Wednesday, January 13, 2010

RCA's Airenergy charger converts WiFi energy to electricity (VIDEO)

Source: Physorg.com

Airenergy is a gadget that can harvest free electricity from WiFi signals such as those from a wireless Internet connection, apparently with enough efficiency to make it practical for recharging devices such as mobile phones.

At the (CES) in Las Vegas this week a RCA spokesman said they had been able to charge a BlackBerry from 30% charge to fully charged in around 90 minutes using only ambient WiFi signals as the power source, although it was unclear on whether the Airenergy was recharged in that time. The Airenergy recharging time depends on the proximity to the WiFi signal and the number of WiFi sources in the vicinity.
The RCA Airenergy unit converts the WiFi antenna signal to DC power to recharge its own internal lithium battery, so it automatically recharges itself whenever the device is anywhere near a WiFi
. If you have a wireless network at home the Airenergy would recharge overnight virtually anywhere in your home. When you need to recharge your phone or other device you plug the Airenergy battery into the phone via USB to transfer the charge.

Harvesting electricity from signals in the air is not new, as anyone who ever built a crystal radio running only on the radio signals it received can testify, but until now no device has been able to harvest enough electricity to make it of practical use. In most modern cities WiFi signal hotspots abound, which might make the Airenergy device a viable option, although in rural areas WiFi sources are less widespread.
A USB charger costing around $40, and about the size of a phone, is expected to be released later this year, with a WiFi-harvesting battery around the same size and price as an OEM battery available shortly after.

Monday, January 11, 2010

Statistics Page

world map hits counter

Introducing the Light Touch interactive projector.

Source: Physorg.com
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UK-based company Light Blue Optics has introduced an extremely compact projector that converts any flat surface into an interactive touch video screen.
The Light Touch interactive is basically a hand-held computer that runs Windows CE and uses a proprietary holographic laser projection (HLP) system to project a virtual touch screen onto any flat surface. The image projected is only 15 lumens, but remains in focus even at long distances.
Holographic refers to the method Light Blue Optics uses to create two-dimensional images by transforming original images into sets of diffraction patterns that are shown on a micro-display and then illuminated by laser light. Diffraction patterns are used because of their high efficiency, since they direct light to where it is needed rather than indiscriminately.
Multiple diffraction patterns are calculated, with each producing a rough version on the image. The viewer's eye then separates the images from the noise and sees them as a clear video image that is always in focus, even when projected onto a curved surface. The lasers produce vivid and bright image colors, and the wide throw angle produces large (10-inch) images even close to the tiny projector.
The Light Touch system detects interactivity via an integrated infrared system that in effect transforms any surface into a touch screen, and this allows users to run the projector and control applications by touching the image. WiFi connectivity and Bluetooth technology are built-in to allow users to connect to the Internet for multimedia sharing and social networking via the projector.
The laser used in the Light Touch projector is a class 1, which means it is completely eye safe, and the projected images are WVGA (Wide Video Graphics Array), which produces a crisp, auto-focused image. The standard flash memory is 2 GB, but there is a micro SD card slot to upgrade to 32 GB storage. The battery life rating is for two hours.
The projector, the first released product of Blue Light Optics, was demonstrated for the first time on 7 January at the 2010 Consumer Electronics Show (CES) in Las Vegas.
More information: Light Blue Optics website: http://lightblueoptics.com/products/light-touch/
© 2009 PhysOrg.com