Researchers apply coating to commercial glass, demonstrating transparency of new energy's solarwindow capable of generating electricity, currently under development. Source: New Energy Technologies, Inc.

by Staff Writers
Burtonsville MD (SPX) Jun 26, 2009

New Energy Technologies has announced that new tests of the Company's ultra-small solar cells for use in its transparent SolarWindow have demonstrated substantially superior performance over current thin-film and solar photovoltaic technologies at generating electricity from artificial light - an important advantage over conventional solar technologies which are limited by their capacity to function well where exposure to direct sunlight is available.

"One of the biggest issues with today's solar products is their dependency on direct sunlight, which our cells have demonstrated the potential capacity to overcome," explained Mr. Meetesh V. Patel, Esq., President and CEO of New Energy Technologies, Inc.

"We're now actively working to coat these cells onto transparent glass in order to fabricate our SolarWindows, which generate electricity and have the potential to be installed virtually anywhere that either direct sunlight or artificial lighting such as fluorescent systems emit visible light.

In contrast, today's building-integrated solar and photovoltaic products are limited to installation on south-facing surfaces, as is the case with currently-available solar materials tested in these newest experiments."

In a series of new experiments, researchers repeatedly tested New Energy's ultra-small solar cells on a 1"x1" substrate against today's popular solar materials for their capacity to produce electricity under varying artificial light conditions, mimicking the levels of light exposure in homes and commercial offices.

In every case, New Energy's solar cells, the smallest reported organic solar cells of their kind in the world, exponentially outperformed all of the conventional materials tested.

Under normal office lighting conditions, without the benefit of outside natural light from windows, New Energy's ultra-small solar cells produced:

Almost 2-fold greater output power density than monocrystalline silicon, an established commercial solar cell material; More than 8-fold greater output power density than copper-indium-selenide, known for its high optical absorption coefficients and versatile optical and electrical characteristics; and
More than 10-fold greater output power density than flexible thin-film amorphous-silicon, a popular 'second-generation' solar thin-film material.

New Energy's solar cells generate electricity not only from the visible radiation found in sunlight but also by using the visible light found in artificial illumination, such as the fluorescent lighting typically installed in offices and commercial buildings.

While the majority of today's solar cells can only be installed where direct sunlight is available, New Energy's cells could be installed close to any source of visible light.

New Energy's SolarWindow technology makes use of an organic solar array, which has the same desirable electrical properties as silicon, yet has a considerably better capacity to 'optically absorb' photons from light to generate electricity and achieves transparency through the innovative use of conducting polymers. Each solar array is composed of a series of twenty ultra-small solar cells measuring less than ? the size of a grain of rice each.

The organic solar cells are fabricated using environmentally-friendly hydrogen-carbon based materials, and successfully produce electricity, as demonstrated in a peer-reviewed study in the Journal of Renewable and sustainable Energy of the American Institute of Physics.

The superior optical absorption properties of New Energy's ultra-small solar cells enables development of an ultra-thin film (only 1/1000th the thickness of a human hair, or 1/10th of a micrometer) that can be utilized to produce a transparent solar window.

In photovoltaic applications such as see-thru windows, where transparency is a primary concern, today's thin film solar cells simply cannot be utilized to produce a transparent solar window for application in homes, offices, and commercial buildings.