Kyoto Institute of Technology introduced a new solar cell that can generate electricity from various sources of light or not just depends on the sun.
With this new technology, solar panels can generate electricity from sunlight, lamp light and infrared light, so it does not have to depend on the sun alone, and more flexible in its placement.
Solar energy technologies use energy from the sun to produce heat, light, hot water, electricity, and even cooling, for homes, commercial and industrial.
There are a variety of technological applications that have been developed to take advantage of solar energy. Technology can be read further below.
Photovoltaics System
Solar cells work by converting sunlight directly into electricity. The electrons in the semiconductor material, the material used to capture sunlight, will move when the sun’s energy in the form of photons hit it. Solar energy is forcing the electrons to move, occur continuously, and consequently there is also a continuous electricity production. Process, which turns sunlight (photons) into electricity (voltage), called the photovoltaic effect.
Solar Cell Module
Solar cells are usually organized into modules that each module can consist of 40 solar cells. Some modules can be arranged to form a PV line fitted with a fixed angle facing south. Or even could be placed in a sun-tracking device, to get more solar energy throughout the day. Several rows of PV could produce enough power for a house. As for industrial applications or power companies, hundreds of lines of PV can be linked to form one large PV systems and sufficient to meet the electricity needs.
Thin Film Solar Cell
Thin film solar cells use several layers of semiconductor material with a thickness in the micrometer scale. Technology allows to create solar cells integrated into rooftops to the skylights. Even solar cells are designed for applications having the same power with actual roof.
The leading provider of digital office equipment, advanced document management solutions and services, Ricoh America Corporation has completed an electronic billboard for Times Square, completely powered by solar power.
Eight19, a collaboration company between Cambridge University and Carbon Trust promises a cheap and flexible solar panel.
This Organic Solar PV type uses a transparent material so that when affixed to the glass will still be able to let the sun go into.
Terry Hope has created the THEKPV (The Hybrid Electric Kinetic Photovoltaic Vehicle), a solar powered bike that is powered by a 50W array of solar panels and has a capacitor for boosting its acceleration capabilities.
Konarka’s Power Plastic technology that creates a flexible thin film solar cell, now available embedded in a solar powered umbrella. SOLARBrella provide power for laptops, iPods, cell phones and other personal equipment.
This tent comes with solar panels and integrated, interior LED lights. You can also use solar panels to charge the battery independently. That’s about 4-6 hours of direct light to yield 2-4 hours tent light. The 7″ (18 cm) solar panel placed on the hub of tents and clicked into place. Fly is then placed on a solar panel & tent, and sun will charge the panel through the clear PVC window at the top of the fly. Unfortunately, like most tents, this one is made from petroleum-based materials (nylon and PVC). Certainly there is a substitute that can be used out there! Tent comes as a four-person and six-person version, and the price is $ 180 (CAD) and $ 220 (CAD) each. For more information, visit Canadian Tire site. [Via]
Solar power is harnessed and applied in ever more interesting and creative ways, and Renu personal power generation and storage system is certainly no exception. Device features a free-standing modular solar panels which, when filled, can be put into a number of extensions to take advantage of the energy collected, including an iPod dock and LED table lamp.
Adventures in microsolar supported by microelectronics and MEMS techniques
Representative thin crystalline-silicon photovoltaic cells – these are from 14 to 20 micrometers thick and 0.25 to 1 millimeter across.
Sandia National Laboratories scientists have developed tiny glitter-sized photovoltaic cells that could revolutionize the way solar energy is collected and used.
The tiny cells could turn a person into a walking solar battery charger if they were fastened to flexible substrates molded around unusual shapes, such as clothing.
The solar particles, fabricated of crystalline silicon, hold the potential for a variety of new applications. They are expected eventually to be less expensive and have greater efficiencies than current photovoltaic collectors that are pieced together with 6-inch- square solar wafers.
The cells are fabricated using microelectronic and microelectromechanical systems (MEMS) techniques common to today’s electronic foundries.
Sandia lead investigator Greg Nielson said the research team has identified more than 20 benefits of scale for its microphotovoltaic cells. These include new applications, improved performance, potential for reduced costs and higher efficiencies.
“Eventually units could be mass-produced and wrapped around unusual shapes for building-integrated solar, tents and maybe even clothing,” he said. This would make it possible for hunters, hikers or military personnel in the field to recharge batteries for phones, cameras and other electronic devices as they walk or rest.
Sandia project lead Greg Nielson holds a solar cell test prototype with a microscale lens array fastened above it. Together, the cell and lens help create a concentrated photovoltaic unit.
Even better, such microengineered panels could have circuits imprinted that would help perform other functions customarily left to large-scale construction with its attendant need for field construction design and permits.
Said Sandia field engineer Vipin Gupta, “Photovoltaic modules made from these microsized cells for the rooftops of homes and warehouses could have intelligent controls, inverters and even storage built in at the chip level. Such an integrated module could greatly simplify the cumbersome design, bid, permit and grid integration process that our solar technical assistance teams see in the field all the time.”
For large-scale power generation, said Sandia researcher Murat Okandan, “One of the biggest scale benefits is a significant reduction in manufacturing and installation costs compared with current PV techniques.”
Part of the potential cost reduction comes about because microcells require relatively little material to form well-controlled and highly efficient devices.
From 14 to 20 micrometers thick (a human hair is approximately 70 micrometers thick), they are 10 times thinner than conventional 6-inch-by-6-inch brick-sized cells, yet perform at about the same efficiency.
100 times less silicon generates same amount of electricity
“So they use 100 times less silicon to generate the same amount of electricity,” said Okandan. “Since they are much smaller and have fewer mechanical deformations for a given environment than the conventional cells, they may also be more reliable over the long term.”
Another manufacturing convenience is that the cells, because they are only hundreds of micrometers in diameter, can be fabricated from commercial wafers of any size, including today’s 300-millimeter (12-inch) diameter wafers and future 450-millimeter (18-inch) wafers. Further, if one cell proves defective in manufacture, the rest still can be harvested, while if a brick-sized unit goes bad, the entire wafer may be unusable. Also, brick-sized units fabricated larger than the conventional 6-inch-by-6-inch cross section to take advantage of larger wafer size would require thicker power lines to harvest the increased power, creating more cost and possibly shading the wafer. That problem does not exist with the small-cell approach and its individualized wiring.
From left to right, Sandia researchers Murat OKandan, Greg Nielson, and Jose Luis Cruz-Campa, hold samples containing arrays of microsolar cells.
Other unique features are available because the cells are so small. “The shade tolerance of our units to overhead obstructions is better than conventional PV panels,” said Nielson, “because portions of our units not in shade will keep sending out electricity where a partially shaded conventional panel may turn off entirely.”
Because flexible substrates can be easily fabricated, high-efficiency PV for ubiquitous solar power becomes more feasible, said Okandan.
A commercial move to microscale PV cells would be a dramatic change from conventional silicon PV modules composed of arrays of 6-inch-by-6-inch wafers. However, by bringing in techniques normally used in MEMS, electronics and the light-emitting diode (LED) industries (for additional work involving gallium arsenide instead of silicon), the change to small cells should be relatively straightforward, Gupta said.
Each cell is formed on silicon wafers, etched and then released inexpensively in hexagonal shapes, with electrical contacts prefabricated on each piece, by borrowing techniques from integrated circuits and MEMS.
Offering a run for their money to conventional large wafers of crystalline silicon, electricity presently can be harvested from the Sandia-created cells with 14.9 percent efficiency. Off-the-shelf commercial modules range from 13 to 20 percent efficient.
A widely used commercial tool called a pick-and-place machine — the current standard for the mass assembly of electronics — can place up to 130,000 pieces of glitter per hour at electrical contact points preestablished on the substrate; the placement takes place at cooler temperatures. The cost is approximately one-tenth of a cent per piece with the number of cells per module determined by the level of optical concentration and the size of the die, likely to be in the 10,000 to 50,000 cell per square meter range. An alternate technology, still at the lab-bench stage, involves self-assembly of the parts at even lower costs.
Solar concentrators — low-cost, prefabricated, optically efficient microlens arrays — can be placed directly over each glitter-sized cell to increase the number of photons arriving to be converted via the photovoltaic effect into electrons. The small cell size means that cheaper and more efficient short focal length microlens arrays can be fabricated for this purpose.
High-voltage output is possible directly from the modules because of the large number of cells in the array. This should reduce costs associated with wiring, due to reduced resistive losses at higher voltages.
Other possible applications for the technology include satellites and remote sensing.
The project combines expertise from Sandia’s Microsystems Center; Photovoltaics and Grid Integration Group; the Materials, Devices, and Energy Technologies Group; and the National Renewable Energy Lab’s Concentrating Photovoltaics Group.
Involved in the process, in addition to Nielson, Okandan and Gupta, are Jose Luis Cruz-Campa, Paul Resnick, Tammy Pluym, Peggy Clews, Carlos Sanchez, Bill Sweatt, Tony Lentine, Anton Filatov, Mike Sinclair, Mark Overberg, Jeff Nelson, Jennifer Granata, Craig Carmignani, Rick Kemp, Connie Stewart, Jonathan Wierer,
George Wang, Jerry Simmons, Jason Strauch, Judith Lavin and Mark Wanlass (NREL).
The work is supported by DOE’s Solar Energy Technology Program and Sandia’s Laboratory Directed Research & Development program, and has been presented at four technical conferences this year.
The ability of light to produce electrons, and thus electricity, has been known for more than a hundred years.
(in Olmedilla de Alarcón, Spain, 60 MW) Finished in September 2008. This power plant uses 162,000 average photovoltaic solar panel to deliver 60 MW of electricity on a sunny day. The whole factory was completed in 15 months at a cost of about 530 million U.S. dollars current exchange rate. Olmedilla built with conventional solar panels, which are made with silicon and tend to heavy and expensive.
(Spain, 50 MW) in 2008 Renovalia develop the power station in Puertollano, Ciudad Real, residential energy parks with an installed capacity of 50 megawatts (MW). The power generated here is equivalent to the annual domestic consumption of electricity of about 39,000 households. The energy produced here will replace the theoretical disposal 84,000 tons CO2/year or 2.1 million tons of CO2 over 25 years during the production.
(Portugal, 46 MW) Completed December 2008. This solar power plant is placed in the municipality of Moura, Alentejo, Portugal, one of the sunniest areas in Europe and besides one of the most economically depressed. The construction involves two stages, first with a built in 13 months and completed in 2008, and the rest will be completed in 2010, with a total cost of € 250 million for the project. The power plant will have an installed capacity of 46 mwp, by more than 376,000 solar panels. Nearly 190,000 panels (32 MW) installed in permanent structures, 52,000 (10 MW) in a single-axis trackers, which follow the sun in the sky, and further 20 MW of power capacity will be added during phase 2 project. This will occupy an area of 320 hectares (130 acres), producing 88 GWh of electricity per year.
(Germany, 40 MW) 550,000 First Solar thin-film CdTe modules. Completed in December 2008 Waldpolenz Solar Park, which is the world’s largest thin-film photovoltaic (PV) power system, built at a military air base east of Leipzig in Germany. The power plant 40-megawatt solar power system using state-of-the-art thin film technology. 550,000 First Solar thin film modules are used, which supplies 40,000 MWh of electricity per year. The investment costs for solar parks Waldpolenz Euro 130 million.
(Spain, 36 MW). Completed in October 2008, power plant that produces 34 GWh per year, which would own 12,000 households and prevent 375,000 tons of CO2. Facilities in seven acres and 172,000 panels houses. Project budget of about € 180,000,000. La Rioja, a region of Spain known for its wine, already covers 62% of electricity with enhanced resources.
Outdoor solar lights uses the identical action to generate power as the solar panels on your ceiling (or that you could set up on your ceiling, if you selected to). Essentially, it applies photovoltaic (PV) cells, which accumulate and switch solar energy into electrical energy. The PV cells apply semiconducting materials to engage the sun’s light, which interacts with the silicon and another components to produce electrical energy. The electrical energy runs over cables which power the battery, which in go powers the light. This is an highly simple explanation, but it will present you the common idea of how solar cells play. They can only make electrical energy from direct sunshine, which is why solar lighting wants a battery in order to be able to light up the dark.
So that the batteries to keep a constant charge, the solar light fixture should be in a position that meets full sunshine for almost of the daylight. If it just gets partial sunlight, because it’s barred by trees or other construction, or because your area has much of cloudy conditions, the batteries will run out earlier, and your fixture will supply light for a lower amount of time. Most outdoor solar lights fixtures own a backup power system which applies rechargeable batteries. Solar lights fixtures which apply a small amount of electrical energy frequently apply small AA Ni-Cad or NiMh batteries. But more strong solar lights fixtures (like head lights) apply a covered lead acid battery.
Photo detectors that automatically evaluate light degrees (like the kind that tells your photographic camera when to apply its flash) are constructed into the solar lights fixtures. They monitor light degrees and turn the fixture off at morning and on at nightfall. But get sure there are no artificial light sources (like a street lights or head light) that may contribute a wrong reading and forbid the light from turning on.
Outdoor solar lights usually utilizes LED bulbs. They apply less power than incandescent bulbs and, with a lifetime of around 20 years, are much longer-lasting. Until lately, solar lights overall has not been as bright as lighting powered straight by direct current electrical energy. But the earliest super bright LEDs can at present illuminate as well as halogen bulbs.
Solar technologies is now highly developed, with some progress is being developed to be used every day.
Below 10 Solar Technologies to note:
You may have seen a calculator that has a solar cell? calculator that does not need batteries, and in some cases do not even have the off button. As long as you have enough light, so the calculator can be on at any time and forever. You may have seen larger solar panels, such as in housing or traffic lights, haven’t you? In this article I will review how solar cell work so it can deliver the energy and drive an electronic device.
Today the demand for electricity has become a major requirement in all corners. The presence of power plants sometimes do not solve the need for electricity especially in remote areas where the terrain is always an excuse. Here an alternative energy that can be easily found in nature and can be used as an alternative free energy replacing conventional electricity, because it can turn on household electronics such as televisions, radios and lights.
Solar cells made from pieces of a very small silicon coated with special chemicals to form the basis of solar cells. Solar cells generally have a minimum thickness of 0.3 mm is made from semiconductor materials incision with positive and negative poles. Each solar cell produces usually voltage 0.5 volts. Solar cells is an active element (semiconductor) that utilizes photovoltaic effect to transform solar energy into electrical energy.
Solar cells contain a connection (junction) between two thin layers made of semiconductor materials, each of which is known as a semiconductor type “P” (positive) and semiconductor type “N” (negative).
N-type semiconductor made of silicon crystals and there are also some other materials (typically phosphorus) within the limits that these materials can provide an excess of free electrons.
Electrons are sub atomic particles are negatively charged, so that the silicon alloy in this case known as N-type semiconductor (Negative). P-type semiconductor made of silicon crystal in which there is a small amount of other material (typically boron) which caused the shortage of material free electrons. Lack or loss of electrons is called a hole. Because there is no or lack of electrons electrically negative charged then the silicon alloys in this case as a semiconductor type-P (Positive).
Composition of a solar cell, the same as a diode, consisting of two layers, called PN junction. PN junction obtained by staining a pure semiconductor silicon (valence 4) with the impurity valence 3 on the left side, and one on the right impurity stained with valence 5.
The effect of the electric field in a PV cell
Operation of a PV cell
Basic structure of a generic silicon PV cell
Thus formed on the left side that is not pure silicon again and called P type silicon, while the right side is called silicon type N. In the pure silicon there are two kinds of electrical charge carriers are balanced. Positive electric charge carriers called holes, while the negative are called electrons. After a desecration process, in the P type silicon formed holes (positive charge carriers) in a very large number compared with the electron. Therefore, in the P type silicon holes are majority charge carriers, while the electrons are minority carriers. Conversely, in the N type silicon is formed of electrons in a very large number so-called majority carriers, and holes called minority carriers.
In the silicon rod there was interaction between the P and the N. Therefore called the PN junction. When present, the P associated with the positive pole of a battery, while the negative polar associated with the N, then there is a relationship called “forward bias”.
Under forward bias, electrical currents arise in a series due to both types of charge carriers. So the electric current flowing in the PN junction is caused by the movement of electron and the movement of holes. An electric current is flowing in the direction of holes movement, but opposite direction with the movement of electrons. Just to further explain, electrons moving in the conductor material can lead to electrical energy. And electrical energy is called as an electric current that flows in the opposite direction to the movement of electrons.
But, if the P associated with negative pole of batteries and the N associated with positive pole, then now formed a relationship called “reverse bias”. In these circumstances, the hole (positive charge carriers) can be connected directly to the positive pole, while the electrons are also directly to the positive pole. So, clearly in the PN junction there is no movement of majority charge carriers either the holes or electrons. Meanwhile, the minority charge carriers (electrons) in the part P moves trying to reach the positive pole of the batteries. Similarly, the minority charge carriers (holes) in the N also moved to reach the negative pole. Therefore, in a state of reverse bias, in the PN junction there is also output current even in very small amounts (micro amperes). This current is often called the reverse saturation current or leakage current.
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Anything interesting in reverse bias. When the temperature of PN junction raised they will be able to enlarge leakage current. Means that if given the energy (heat), the minority charge carriers in the PN junction grows. Because the light is one form of energy, so if there is light that hit a PN junction may also produce enough energy to generate charge carriers. This symptoms are called photoconductive. Based on the photoconductive symptoms made of photodiode electronic components from PN junction.
In reverse bias, with increasing intensity of light that hit photodiode can increase the level of leakage current. Leakage currents can also be enlarged by increasing the battery voltage (reverse voltage), but the addition of leakage currents were not significant. When the batteries in the reverse bias circuit is removed and replaced with a load of resistance, the provision of light that can cause charge carriers both holes and electrons. If the illumination light is increased, current output was greater. Such symptoms are called photovoltaic. Light can provide enough energy to enlarge the number of holes in the P and the number of electrons on the N. Based on the symptoms of this photovoltaic electronic components can be created photovoltaic cell. Because usually the sun as a source of light, the photovoltaic cell is also called the solar cell (solar cells) or a solar energy converter.
So the solar cell is essentially a large photo diode and designed by referring to the photovoltaic symptoms so that could produce the greatest possible power. P type silicon is the very thin surface layer so that light can penetrate directly reach the junction. Part P is given ring-shaped nickel layer, as a positive output terminal. Under the P is the N type that is coated with nickel as well as the negative output terminal.
To obtain a large enough power required much of solar cells. Usually, solar cells arranged form the shape of the panel, and is called the photovoltaic panels (PV). PV as a source of electric power was first used in satellites. Then PV as an energy source for cars, so there are solar electric car. Now, in foreign countries, PV has started to be used as a roof or wall of the house. Sanyo has made even a semi-transparent PV that can be used as a substitute for glass.
After getting the output of the solar cell is a direct electrical current can be used to load utilized. But also the electric current can be used as a charge stored by the battery to be used when needed, especially at night because there was no sun.
If the solar cell is used for storage into the battery, then the resulting voltage magnitude must be above the battery specification. For example the battery used is 12 volts, the voltage produced by solar cell must be above 12 volts in order to perform charging.
We recommend that before carrying out the charging battery should be empty because the incoming flow will be filled with the maximum. The unit capacity of a battery is the Ampere-hour (Ah) and these characteristics are usually found on the label of a battery. For example a battery with 10 Ah capacity will fill up for 10 hours with the solar cell output currents of 1 Ampere.
Kyocera, one of solar cell manufacturers, build solar cell panels plant in Spain under the auspices of local firms Avanzalia. When the project is completed, this plant becomes the world’s largest electricity plant with a solar power source.
August 2008, the factory is located in the Castile-La Mancha Spain will produce electric power 18 mega watts. Power is enough for 9200 homes. Total 89.3200 Kyocera PV solar cell modules will be installed. 3300 tons of iron needed for iron buffer. It was so big, wide field required 80 acres or equivalent to 100 foot ball court.
Location of the solar plant at an altitude of 800 meters above sea level, so that the air temperature is more stable plus the sun in that regions can produce annually 1892 kWh/m2.
Grid-connected system was applied to many urban areas housing, existing electricity network. The purpose of using solar panels, to save the cost of excessive electricity consumption and help reduce the greenhouse effect caused by the use of fossil fuels which cause excessive air pollution. Electrical energy which is in turn, channeled into the electricity networks that already exist and can be stored in the electricity network. This term is called the Hybrid System, which combine solar power plants with electricity network. Solar systems can also be combined with other power plants such as PV-Generator Hybrid, Hybrid PV-Microhydro, Hybrid PV-Wind and can even be combined into 3 systems of different power to Hybrid PV-Wind-Generator.
The following illustration application of grid connected systems in housing
Caption:
1. Solar panels installed at suitable locations to generate optimal power.
2. Inverter (Controller) function to change direct current (DC) produced by PV into alternating current (AC) that can be applied to household electronic equipment.
3. Box distribution function to distribute the AC current through the PV generated electricity network.
4. Discharging the burden of household air-conditioning system.
5. Electric meter show the current of electricity network will b
