I agree, Beth, the large buildings have the scale. A small savings per window would deliver significant power. In a dense area like Manhattan, there may be some limitations on direct sunlight, but around most of the country, these large buildings are pretty clear of obstruction.
Commercial buildings would be a great application and these mega buildings also have some sort of budget which would allow them to invest in the storage capabilities that are so critical to making this effective. Especially since many mega buildings in cities (I'm thinking NYC) have lots of self-induced shade due to their size and number--a factor that could limit the windows' ability to harvest energy even on sunny days.
Energy harvesting technologies are well-known to produce really tiny amounts of electrical current -- at the microamp- and even nanoamp-level in some cases. Any idea how much these films could produce, Ann?
I agree entirely. With a consumer grade cell at 15%, a 4% cell that will probably not be properly aligned is going to need to be fairly cheap. Don't get me wrong, I love solar, I even converted my lawn mower to solar. The idea of a window that still functions as a window while collecting solar energy is fantastic, but if each window only collects 1Wh for a sunny day, the window will need to be as cheap as glass.
I agree with you totally. This idea of adding solar cell polymer material to windows is the best one yet for generating electricity. With the amount of sunlight passing through windows daily, I would imagine sufficient amounts of electricity can be generated easily. The next item to include in the energy conversion process is an innovative way to store the energy for use on cloudy days.
This is a really cool development. The real key (costs aside) will be integration of "power windows" into a local smart grid. In this case local would mean within the confines of the building that the windows are installed in. What a great way to harvest power for low voltage lighting, though.
It's sources report the following efficiencies for conversion of sunlight into biomass (usable energy)
Plants 0.1% - 2 %
Crops 1% - 2%
Sugarcane 7% - 8%
At 4%, this device is on the high-side when compared to energy-harvesting bio-fuels. With even more development, this material could be quite a winner -- and we could continue to use our corn and soybeans to feed people and livestock rather than engines...
At 4% efficiency, and a practical application on the south side of office buildings, cost is going to be the deciding factor. Let's hope that taxpayers don't get stuck funding this as the total outpput could be rather restricted.
I wouldn't mind having those windows, either, even here in the woods. There are various types of films that can be added to windows that purport to do something similar. Here are some recent ones:
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