Last week, New Energy Technologies Inc. showed its technology that enables glass to generate electricity through spray-on solar PV to investors and members of the media. The technology, which is called the SolarWindow, aims to provide solar energy to building facades by spraying an electricity-generating coating on to glass. During the demonstration, the researchers compared the cost of the SolarWindow technology to traditional rooftop solar systems saying that the SolarWindow technology provides up to three times more savings in electricity costs.
According to a press release, engineers modeled a 40-story building, similar to Tampa’s landmark 100 North Tampa, as an example. They estimated an annual cost-savings of $40,000 to $70,000 when installing New Energy’s SolarWindow to exposed window facades, which they contrasted with a polycrystalline silicon module installation on the rooftop that would produce $20,000 in energy savings per year.
“I’m eager to aggressively advance this technology towards commercial prototyping in preparation for eventual full-scale production to capitalize on our market of more than five million commercial buildings and 80 million detached homes in America,” said president and CEO, John A. Conklin.
The company expects to publish comprehensive performance data in upcoming weeks, following independent, third-party measurement and engineering validation.
The all-important numbers such as installed cost and efficiency were not discussed. Comments:
Anonymous September 24, 2010 Tch tch. Once again we see a picture of a transparent solar cell -- when are we going to learn? You can only get energy by absorbing sunlight; consequently, an efficient solar cell should be essentially black. Non-visible light could be selectively absorbed except that a lot of UV in sunlight doesn't get through ordinary window glass and the infrared solar spectrum is relatively low energy. Even then, for comercial buildings you'd have to replace the integral sun blocking film with the PV material otherwise very little UV or IR would be getting to the cells. They imply something like twice the efficiency of monocrystalline cells i.e. >35% which goes beyond improbable since the cell depicted appears to be transmitting more than 65% of the incident light (note the picture is taken against a backdrop, consequently, light has to have passed through twice and yet the backdrop is barely obscured). The bottom line is either you capture light and turn it into current - in which case your cell looks dark - or you don't.
The usefulness of producing electricity from artificial light seems pretty sketchy. There is the weak case that bifacial windows would reduce the amount of energy escaping from a building as light from interior lighting but the relatively low light levels compared to sunlight would make this very marginal. Also, one could just as easily increase the reflectance of windows to improve the net efficiency of interior lighting.
You've also got to question the apples and oranges comparison of conventional solar on the roof versus something else on the building facade. Does a tall building have more available wall space than roof space? of course it does -- there's even enough of a difference that a south facing facade can produce more power than the roof despite the non-optimized tilt (with the possible exception of Siberia) although at a higher $/kWh cost. No high-rises to the south please!
richcat November 7, 2010 Leading Solar Testing Agency Confirms New Energy's Power Output for its SolarWindow™
See-thru spray-on technology turns ordinary glass surfaces into electricity-generating SolarWindows™, able to outperform rooftop solar by 300%.
Burtonsville, MD – November 1, 2010 – New Energy Technologies, Inc. (OTCBB: NENE) announced today that Florida Solar Energy Center (FSEC), a leading American certification and testing laboratory for solar products and equipment, has validated the Company's power production modeling calculations for its novel, SolarWindow™ technology.
SolarWindow™ is the first-of-its-kind see-thru glass window capable of generating electricity, and able to outperform conventional rooftop solar module installations by more than 300% when applied to the facades of commercial tall buildings and skyscrapers.
Engineers modeling a 40-story building, similar to Tampa's landmark "100 North Tampa," estimate annual cost-savings of $40,000 to $70,000 when installing New Energy's SolarWindow™ to exposed window facades. In contrast, mounting today's popular poly-crystalline silicon modules rack-mounted on the rooftop produces only $20,000 in energy savings per year.
"We have long anticipated that applying SolarWindow™ to exterior glass surfaces of commercial towers could generate energy savings several-fold greater than today's rooftop solar systems," explained Mr. John A. Conklin, President and CEO of New Energy Technologies, Inc. "It's wonderful to have these power modeling calculations now validated by FSEC, a highly-respected independent solar testing agency.