Australian solar power company Sunengy has partnered with India’s power utility Tata Power for the pilot plant of Liquid Solar Array (LSA), a floating-on-water solar technology.
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.
One of the things that a potential obstacle in the development of solar energy is limited space. All existing solar panels in a solar power generation should receive sunlight for at least the same intensity to produce electrical energy optimally. Therefore, all the solar panels should be installed in rows, which mean that also require large open space.
In addition, the performance of solar panels that are widely used today are still influenced by the temperature generated by the environment and direct sunlight. The higher the temperature, the performance of a solar panel will also decrease.
The folded Solar Ibex could be a perfect camping companion because it can utilize solar energy for cooking, boiling and back at up to 300 degrees Celsius, and adjustable timer feature. The Solar Ibex is a lightweight, packable, and a zero carbon. Built-in motor gear and auto tracking Sun ray concentrator drive parabolic reflector toward the sun all the time.
Mags Harries and Lajos Heder designed an electric garden filled with sunflower solar collector. Installations located in Austin, Texas, and consists of 15 elements such as flowers that capture energy from the sun and light at night. Sunflowers produce enough energy during the day to power the lights at night and all the additional power is channeled into the box for credit. Lighting generated by a series of LEDs arranged in a flower. An unusual form of panels required they must be custom made. In addition, a special transparent blue gel squeezed into the panels to create shade for the bike path below, create a blue light.
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.
Solar technologies is now highly developed, with some progress is being developed to be used every day.
Below 10 Solar Technologies to note:
Flat collectors, and even concentrator is a tool used to collect solar radiation energy so that thermal energy produced can be used in more practical for a variety of processes. Flat solar collector consists of a transparent cover, absorber and insulator. Solar radiation that falls on the surface of the transparent material in the short wave will be forwarded by transparent material and then absorbed by absorber. Black color have an ability to absorb a larger radiation so that most of the sun radiation will be absorbed. Absorption of this radiation will create a high temperature absorber. Heat radiation emanated by absorber but in the form of long waves. Most of the transparent material has an opaque nature of long wave radiation and therefore part of the long wave radiation reflected back by this transparent material to the absorber. Some radiation is absorbed will be reflected back and the rest will experience the same process that is part reflected back to the absorber. Thus, the loss of heat due to radiation can be minimized by flat collector. In addition, the transparent cover also functions as a heat loss barrier carried by the air above the absorber to the environment.
Heat from the absorber is used through heat exchanger to the media of heat carrier. Media of heat carrier commonly used can be air or water. When using water as the media, absorber will conduct heat to the surface of the outside pipes. Then take heat conduction from the outside surface to the inside surface. With the process of convection, heat will move from the inside surface to the water that flows in the pipes, so the water temperature will increase. Water with a high temperature and then used in the other parts of the outside collectors flat. A similar process occurs when air is used as a medium of heat, but in this case the pipe is rarely used. The air above (or below) the absorber heated through convection due to direct contact with the absorber. High temperature air is then flowed out of collectors than used in processes that require hot air.
The performance of a solar collector will depend on the absorptivity characteristics of the absorber, transmissivity of transparent material, overall heat transfer coefficient of the insulator, the transparent material and the absorber.
Absorptivity is the portion of light that is absorbed by an object; transmissivity is the portion of light that is forwarded by an object, while the overall heat transfer coefficient is a power of heat transfer or the opposite of heat resistant.
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