Technology company SolarWindow have developed a glass solar panel that could replace window and help power homes or buildings.
Now, researchers have developed novel technology that allows solar panels to be fitted naturally into residential or commercial settings.
Installation of a transparent luminescent solar concentrator allows windows to create solar energy while maintaining their transparent appearance.
Solar power is an inexhaustible natural resource, as long as the sun continues to emit light. Given environmental and political concerns about dependence on coal and gas power, there has been an upsurge of interest in renewable power sources.
Solar power typically uses photovoltaic cells that harness the energy from sunlight and convert it into electricity. A photovoltaic cell uses a semi-conductor that absorbs radiation from the energy. The semi-conductor then emits electrons, which can be used as electricity to power homes and industry.
Newer prototypes from SolarWindow are more transparent giving that ‘Window Effect’.
There are several limitations to current solar technology. First, solar panels must be oriented to directly face the sun to optimize electricity production.
Installation of fixed panels can be difficult, as there will be times of day when electricity production is lower than others. Furthermore, the efficiency of photovoltaic cells is limited.
The best available photovoltaic cells have a 20% efficiency, meaning that 20% of the energy in the sun’s rays is converted to electricity.
A final limitation is that solar technology can be difficult to implement in urban environments where space is at a premium. The tops of buildings provide some of the only usable space for solar panels, which limits their widespread adoption in urban environments.
Environmental technology researchers have been investigating ways to improve upon existing solar technology. Now, new technologies have emerged that allow windows to be converted to solar panels without interrupting their aesthetic appearance.
Early attempts to use apply solar photovoltaic cells to windows were limited to colored glass. This approach involves the application of a thin layer of solid-state solar cells to conventional glass. The layer of solar photovoltaic cells is as little as 3 microns thick.
Research teams like the ones at SolarWindows are now seeking of ways to improve efficiency of the solar glass panel.
Glass can be produced in black, blue, green, reds, or other colors. However, these colors vary in efficiency of the resulting solar power output.
The average colored glass achieves 12% efficiency of solar rays captured and converted to energy. A downside to this approach, however, is that tinted windows can be visually unappealing.
Recently, a team at Michigan State University announced that they had created solar glass that is transparent.
The technology uses small organic molecules that absorb certain nonvisible wavelengths of light. By picking up just ultraviolet and near infrared wavelengths, the molecules can guide this light to thin strips of photovoltaic cells.
Here, it is converted to electricity that can be transmitted via miniscule wires as small as the width of a human hair. The result is a nearly-invisible solar power generating system that maintains the transparent appearance of glass.
Another exciting development in this area is the ability to “spray paint” solar cells onto surfaces. Given that spray coating is already used to provide thin, even layers of industrial and biologic materials to surfaces.
Applying this spray paint approach to evenly distribute photovoltaic cells provides the potential to coat nearly any surface with solar harvesting technology.
According to some models, solar window technology could produce 50 times more energy than existing rooftop models.
The Michigan State University team acknowledges that the efficiency of their model is lower than some alternatives, producing 5% efficiency when fully optimized. They expect that efficiency will increase rapidly as the technology continues to develop. This provides the potential for solar windows to generate enormous amounts of energy.
One of the most promising applications for the new transparent luminescent solar concentrators is the ability to transform large glass buildings into energy producers.
Urban environments are high energy users but currently have low potential to produce renewable energy. Transparent solar windows provide an opportunity to convert large office buildings to net energy producers.
The technology is expected to be scalable and relatively low cost, making this an attractive option for a range of commercial applications.
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Image Credit: SolarWindow