An exciting technology is being developed by New Energy Technologies (NENE.OB) and the Department of Energy’s National Renewable Energy Lab (NREL) – a window that can produce solar energy in both natural and artificial light.
An electricity-generating coating is sprayed onto a SolarWindowTM enabling them to retain their transparency while generating energy.
So far, scientists have demonstrated it can power indoor lights, appliances, and even the rotor blades on a small helicopter.
The solar coatings are less than 1/10th the thickness of ‘thin’ films and make use of the world’s smallest functional solar cells, shown to successfully produce electricity in a peer-reviewed study published in the Journal of Renewable and Sustainable Energy of the American Institute of Physics.
The key to the window is the wiring, which is deposited in an ultra-fine grid patter, making it virtually invisible to anyone looking through the window.
Last month, New Energy and NREL scientists successfully fabricated their largest-area organic solar PV module to date – over 14 times larger than previous ones.
“It’s very exciting that we’ve not only achieved an important milestone with respect to the size of our SolarWindowTM, but we are now able to confidently tackle two of the most important factors to eventual commercialization – the structure and transparency of the wiring system which transports the electricity generated on see-through glass, and overall performance,” explains John Conklin, CEO of New Energy Technologies.
To generate electricity on the window, researchers creatively layer and arrange unique, ultra-small see-through solar cells on to glass.
Solar cells are arranged in a network and connected by the ‘invisible’ grid-like wiring system. Systems used in earlier prototypes were relatively thick and bulky, and applied to glass in ways that obstructed light, preventing the amount of light absorbed necessary to produce electricity, and significantly reduced transparency.
The ‘invisible’ wiring system allows for more efficient collection and transport of electrons, both important for improving circuit current and overall efficiency. The system helps mitigate electrical ‘road-blocks,’ which restrict the flow of electrons with regions of high resistance, by creating a kind of low-resistance ‘highway’ for electron transport. Without a conductive grid system, resistive losses can significantly reduce power production.
Scientists recently demonstrated the windows powered lights on a scale-model house by exposing the window to artificial light from fluorescent lamps, mimicking lighting typically installed inside offices.
In artificial light, SolarWindowTM technology outperforms today’s commercial solar and thin-films by as much as 10-fold under low-intensity irradiance.
Researchers then repeatedly opened and closed the window shades, successfully powering LED lights each time the window was exposed to natural light. This demonstration mimicked outdoor exposure such as sunlight on the exterior face of commercial buildings – New Energy’s initial target market and a promising early application of its technology.
Importantly, scientists demonstrated the window’s ability to generate ‘voltage’ and ‘current’ necessary to power lighting and mechanical devices and appliances. They also successfully powered the mechanical rotor blades of a small helicopter using only a single, small-scale window prototype. Continue reading more…