http://www.engadget.com/
by
Andrew Tarantola
@terrortola
2 hours ago
Army researchers at the Redstone Arsenal have announced a significant breakthrough in solar energy production. They've created a photovoltaic solar panel that is smaller, more robust and less expensive to build and operate than any other panel currently available. Virtually every solar panel currently in existence relies on a pure silicon construction, however the band gap (the wavelength of light that it can actually be absorbed and converted into electricity) of single crystal silicon is exceedingly narrow compared to the full spectrum shining down from the Sun. Not only does this mean that conventional panels are missing out on potential power, the ultraviolet and infrared wavelengths actively damage the panels by causing them to heat, warp and crack.
The Army's panel, on the other hand, sandwiches super thin layers of metals like silver and gold between the semiconductor layers. With these added layers, the panels offer a wider band gap for energy generation and can be tuned to reflect the harmful rays as well. What's more, the Army's panels generate the same amount of energy regardless of the angle that sunlight is hitting it. That means they don't have to be affixed to expensive and motorized Sun-tracking stands.
The technology is still in its very early stages, explained Wayne Davenport, Optical Sciences Function Chief of the Weapons Development and Integration Directorate, in a statement. "As with many basic research projects, the near-term benefits are sometimes yet undefined but are clearly worth the investment," Davenport continued. "The Army's research laboratories at AMRDEC continue a legacy of high quality research projects and I expect to see many more of these type projects transition to the Warfighter in the future."
[Image Credit: AFP/Getty Images]
New energy cell can store up solar energy for release at night
By Dario Borghino
- July 7, 2015
2 Pictures
Researchers have, for the first time, found a way to
store
electrons generated by photoelectrochemical (PEC) cells for
long periods of time (Credit: UT Arlington)
electrons generated by photoelectrochemical (PEC) cells for
long periods of time (Credit: UT Arlington)
A photoelectrochemical cell (PEC) is a special type of solar
cell that gathers the Sun's energy and transforms it into either
electricity or chemical energy used to split water
and produce hydrogen for use in fuel cells. In an advance that could
help this clean energy source play a stronger role within the smart
grid, researchers at the University of Texas, Arlington have found a way
to store the electricity generated by a PEC cell for extended periods
of time and allow electricity to be delivered around the clock.
Currently, the electricity generated by a PEC cell could not be stored effectively, as the electrons would quickly "disappear" into a lower-energy state. This meant that these cells were not a viable solution for a clean-energy grid, as the electricity had to be used very shortly after being produced. That is, on sunny days, at a time when standard PV panels would already be producing energy at full tilt.
Now, researchers Fuqiang Liu and colleagues have created a PEC cell that includes a specially designed photoelectrode (the component that converts incoming photons into electrons). Unlike previous designs, their hybrid tungsten trioxide/titanium dioxide (WO3/TiO2) photoelectrode can store electrons effectively for long periods of time, paving the way for PEC cells to play a bigger role within a smart energy grid.
The system also includes a vanadium redox-flow battery (VRB). This is an already established type of energy storage cell that is very well-suited for the needs of the electrical grid as it can stay idle for very long times without losing charge, is much safer than a lithium-ion cell (though less energy-dense), is nearly immune to temperature extremes, and can be scaled up very easily, simply by increasing the size of its electrolyte tanks.
According to the researchers, the vanadium flow battery works especially well with their hybrid electrode, allowing them to boost the electric current, offering great reversibility (with 95 percent Faradaic efficiency) and allowing for high-capacity energy storage.
"We have demonstrated simultaneously reversible storage of both solar energy and electrons in the cell," says lead author of the paper Dong Liu. "Release of the stored electrons under dark conditions continues solar energy storage, thus allowing for continuous storage around the clock."
The team is now working on building a larger prototype, with the hope that this technology could be used to better integrate photoelectrochemical cells within the smart grid.
A paper describing the advance appears in the latest edition of the journal ACS Catalysis.
Source: UT Arlington via Kurzweil AI
Currently, the electricity generated by a PEC cell could not be stored effectively, as the electrons would quickly "disappear" into a lower-energy state. This meant that these cells were not a viable solution for a clean-energy grid, as the electricity had to be used very shortly after being produced. That is, on sunny days, at a time when standard PV panels would already be producing energy at full tilt.
Now, researchers Fuqiang Liu and colleagues have created a PEC cell that includes a specially designed photoelectrode (the component that converts incoming photons into electrons). Unlike previous designs, their hybrid tungsten trioxide/titanium dioxide (WO3/TiO2) photoelectrode can store electrons effectively for long periods of time, paving the way for PEC cells to play a bigger role within a smart energy grid.
The system also includes a vanadium redox-flow battery (VRB). This is an already established type of energy storage cell that is very well-suited for the needs of the electrical grid as it can stay idle for very long times without losing charge, is much safer than a lithium-ion cell (though less energy-dense), is nearly immune to temperature extremes, and can be scaled up very easily, simply by increasing the size of its electrolyte tanks.
According to the researchers, the vanadium flow battery works especially well with their hybrid electrode, allowing them to boost the electric current, offering great reversibility (with 95 percent Faradaic efficiency) and allowing for high-capacity energy storage.
"We have demonstrated simultaneously reversible storage of both solar energy and electrons in the cell," says lead author of the paper Dong Liu. "Release of the stored electrons under dark conditions continues solar energy storage, thus allowing for continuous storage around the clock."
The team is now working on building a larger prototype, with the hope that this technology could be used to better integrate photoelectrochemical cells within the smart grid.
A paper describing the advance appears in the latest edition of the journal ACS Catalysis.
Source: UT Arlington via Kurzweil AI
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