Rainbow Solar Inc. (RSI) has produced a transparent, photovoltaic glass window producing power 80-250 watts. Although this is not the “first solar window,” it seems that the RSI has taken a big step forward.
Sunhope, award-winning project by Joseph Cory and aerospace engineer Dr. Pini Gurfil is a breakthrough low-cost easily-deployable system that collects solar energy with very small environmental footprint.
Tegolasolare is the Italian company that works to bring the language of historical architecture in the modern world through solar panels. By combining tradition and modernity, they have developed a roof tile made from red clay that is similar to traditional tiles of terracotta, but by an embedded photovoltaic panel.
Like the story of a fictional movie, but Japanese space agency plan so serious: In 2030 they will capture solar energy in space and sends it to Earth via laser or microwave.
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.
Some solar powered fountain is very beautiful on the market today, and this is a good way to introduce new features to your garden without using additional electricity from the main power supply.
The main advantage of solar powered garden fountain is the ability to leave them in the active state continuously, without worrying about how much electricity they use.
For the gardener who is more experienced and general DIY fanatics, you may be interested to build your own solar powered water fountains. If this happens, you may want to see links to other sites at the bottom of this page.
Powering a garden fountains can be very complicated in many situations such as running underground cables can be quite expensive, and cables laying at the top can be seen messy and unsafe.
This is another big advantage to use solar energy to power your fountain. Solar fountain can be used throughout the year, as long as the temperature in your garden does not fall below freezing. It is advisable to power off your solar fountain and place it in the room during the winter, just as a precaution.
A solar powered fountain work on the same principle of solar cells to collect energy, which then power your fountain pump.
The history of “Photovoltaic” (PV) industrial development has been running about 50 years, and have been many studies done in the hope that one day could produce cheap solar cells and feasible compared with artificial electricity (hydro or nuclear) to solve the problem of availability of environment friendly electricity at all levels of this world.
In the late 19th century, solar electricity discovered by German physicist named Alexandre Edmond Becquerel accident where the sun rays fall on the solution of electro-chemical research materials, so the charge of electrons in the solution increases, there is no scientific explanation of the event. Not until the early 20th century, Albert Einstein called the discovery of this natural electrical event with “Photoelectric Effect”, which is the basic understanding of the “Photovoltaic Effect” (Albert Einstein got the Nobel Prize in Physics). 
“Photoelectric Effect” comes from Einstein’s observations on a plate of metal release “photon” particles of light energy when exposed to sunlight. Photon continuously urged metal atoms and form a particle “Photon Energy”-is the wave of light energy.
Ultraviolet light waves, light that are high charged photon energy and short wavelength, while red light (infra-red) is low charged photon energy and long waves.
Then around the year 1930, research continued and related to discovery of the “Quantum Mechanics” concept, to create new technologies “solid-state”, which then the Bell Telephone Research Laboratories company create the first solid Solar Cell.
Year 1950 – 1960, technology of solar cell design and efficiency continued and applied to the spacecraft (photovoltaic energies). In 1970’s, the world encourage “renewable” alternative energy sources and environmentally friendly, then the PV is applied to the “low power warning systems” and “offshore buoys” (but the PV production could not be much because it is still “handmade”).
Just in 1980, the PV companies joined with government energy agencies in order to produce the PV cells in large numbers, so the price of solar cells can be more suppressed as low as possible.
Revolutionary of photovoltaic applications in the architectural building has undergone rapid development, starting from ordinary technology to high technology in the 3rd generation, they are:
1. First generation (the 1980s)
PV panel module with an iron framework just mounted on the field of building flat roof with a brace (tracking).
2. Second generation (the 1990s)
Photovoltaic cells (PV) developed more integrated part of building materials: roof materials (tiles, shingles).
3. Third generation (year 1997)
Chip / PV module was developed into a whole architectural integration in building materials and advanced applications.
Applications of PV Third Generation
a. Form of shingles (thin film crystalline)
b. Form of cladding (curtain walls)
In general, the energy utilization of solar PV have been popular in the world in the field:
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.
.
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.
In general, energy sources are categorized into two parts namely non-renewable energy and renewable energy. Fossil energy sources are among the first group that the bulk of activity in the world using these conventional energy.
It is no doubt that the solar photovoltaic is one source of environmentally friendly energy and is very promising in the future, because there is no pollution produced during the process of energy conversion, and more widely available source of energy in nature, namely the sun.
Fundamental issues in solar cell technology is a very low efficiency in turning solar energy into electrical energy, which to date the highest efficiency can be achieved no more than 20%, and even then in a laboratory scale.
For that in developed countries, research on solar cell is a very big concern, especially with the issue of environmental clean.
From light into electricity
In a simple solar photovoltaic consists of the p-type and n junction semiconductor material (pn junction semiconductor) that if by the sun there will be a flow of electrons, electron flow is well known as the electric current flow. While the structure of the solar cell is as shown in Figure 1.
Figure 1. Structure of a thin layer of solar photovoltaic in general
The main part of the energy changes of sunlight to electricity is the absorber, however, each layer is also very influential on the efficiency of the solar cell. Sunlight consists of various types of electromagnetic waves in a spectrum can be seen in figure 2. Therefore here absorber is expected to absorb as much solar radiation derived from sunlight.
Figure 2. The spectrum of solar radiation
More detail can be explained that the sun consists of a photon-photon, if it happen to solar cell surface material (absorber), will be absorbed, reflected or simply passed (see Figure 3), and only photons with certain energy level that will liberate electrons from atomic bonds, so that electrical current flows. Energy levels is called band-gap energy which is defined as the amount of energy required to discharge electrons out of its covalent bond so that there electric current flow. To free electron from its covalent bond, photon energy (hc/v) must be slightly larger or above than the band-gap energy. If the photon energy is too much of the energy band-gap, then the extra energy will be converted in the form of heat in a solar cell. Therefore it is important to the solar cell to regulate the materials used, namely by modifying the molecular structure of the semiconductor used.
Figure 3. Radiative transition of solar photovoltaic
Of course, that the efficiency of solar cell can be high if the photons from sunlight to be absorbed that as much, then reduce reflection and increase recombination and conductivity of the material.
To be able to make that a photon is absorbed can be as much, then the absorber must have an energy band-gap with a wide range, making it possible to absorb sunlight so energy has a variety of these. One of the many materials being studied are known CuInSe2 is one of the direct semiconductor.
So many advantages of solar photovoltaic as described above was not a polemic and not just stop, saying there was a solar photovoltaic is true when the energy change process there is no pollution produced, but have we calculated how much pollution has been generated in the process manufacturing, small compared to the resulting efficiency. Now the challenge here is indeed how to increase efficiency, which would affect its economic value.
Article You May Be Interested In Reading: Solar Electric
Solar system has a mechanical and electrical components that can convert and store electrical energy that can be used to run your home. Start the calculation that you want to do is an energy audit. You need to evaluate the amount of power that will be needed per day preferably in kilowatts / hour. So the need to consider is the location of your home. That will determine the type of solar system you need is a factor such as climate, number of days of peak sunlight per day, average rainfall and number of days of peak sunlight per year. This calculation can be done by companies that make solar electricity system, and they will guide you in choosing solar electric power systems that are appropriate for your home.
Solar electric power system consists of several components. Some of the components that you will find in the solar electric power system is a primary collector, an inverter, a circuit breaker, battery, charge controller, for collectors and mount the display panel. Collector is a component that collects the sun’s energy. In normal cases, is a solar panel collectors. Collectors on the roof is still using the cushion. Location of solar panels is very important and must be in place where the sun will fall in the maximum on it. Is the ideal place solar panels on the north-south as it will ensure that even if the sun from east to west, the panel get the sun for longer duration.
Inverter is the component that will convert the 12 volt DC power to AC power. Based on the location of the power inverter can convert the 110 volt DC to 220 volt. One of the most important component is the circuit breaker or fuse box. This component has a switch and fuse is important to set the transfer energy from the solar panel to the battery or directly to the outlets. Circuit Breakers control the amount of power that will flow to the outlet and will act as security devices for the application.
If you want to have the storage, then you need to buy one or more batteries depending on your needs. If you have then you need a battery charge controller. This component will ensure you are not over or less in charging battery that will reduce the ability of the battery.
Article You May Be Interested In Reading: Solar Hot Water
Executive Summary about Nanosolar by nanosolar.com -MICHAEL MOYER
Imagine a solar panel without the panel. Just a coating, thin as a layer of paint, that takes light and converts it to electricity. From there, you can picture roof shingles with solar cells built inside and window coatings that seem to suck power from the air.
Cost has always been one of solar’s biggest problems. Traditional solar cells require silicon, and silicon is an expensive commodity (exacerbated currently by a global silicon shortage). That means even the cheapest solar panels cost about $3 per watt of energy they go on to produce.
Nanosolar’s cells use no silicon, and the company’s manufacturing process allows it to create cells that are as efficient as most commercial cells for as little as 30 cents a watt. “It really is quite a big deal in terms of altering the way we think about solar and in inherently altering the economics of solar.”
In San Jose, Nanosolar has built what will soon be the world’s largest solar-panel manufacturing facility. California, for instance, recently launched the Million Solar Roofs initiative, which will provide tax breaks and rebates to encourage the installation of 100,000 solar roofs per year, every year, for 10 consecutive years (the state currently has 30,000 solar roofs). The company is ready for the solar boom.
NANOSOLAR: Solar-cell Coating
Executive Summary about Nanosolar by Silicon Valley
Solar panels are big, clunky, heavy, require special installation, and, if they break, replacing them can be quite expensive.
The PowerSheet is made from a layer of solar-absorbing nano-ink that is printed onto a foil-thin metal sheet.
Because of the ever-increasing costs of energy and the obvious environmental impact of burning up fossil fuels, turning to alternative energy sources such as solar energy is a priority.
Article You May Be Interested In Reading: Solar Heater
