One day, windows are likely to provide the electricity for homes and businesses. Invisible solar technology took another step towards reality this week when New Energy Technologies announced that collaboration with scientists at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) resulted in a 70-square-inch see-through glass solar module.
The solar window is over 14 times larger than other see-through modules made at the NREL, and the largest in the world so far.Under the guidance of New Energy principle scientist Dr. Scott Hammond, NREL scientists applied electricity-generating coatings to glass. Made of conductive polymers, the coatings are produced through an organic synthesis process. The end result is revolutionary BIPV, or building-integrated photovoltaics.
Last month, New Energy announced that they were using a high-speed, high-volume solution coating process, another important development on the road towards a viable commercial organic photovoltaic (OPV) product.
New Energy confirmed that this latest solution-coating technique is compatible with roll-to-roll fabrication methods that are commonly used for printing, which means that OPVs have the potential to be manufactured on a large scale. New Energy foresees that the process will eventually mean that solar windows will be produced faster, cheaper and safer than conventional photovoltaic panels.
Although this latest achievement is a big step forward, obstacles to widespread OPV production remain. The biggest resistance to the technology comes from those who view it as too energy-inefficient. Compared to conventional residential solar panels that have efficiency rates that range from 11 to 15 percent, current OPVs on the market have 4 to 5 percent efficiencies.
So far, the efficiency of solar windows has been even lower. Low efficiency may not be a deterrent, however, if the costs of the windows become inexpensive enough.
The real challenge of solar window technology is developing a way to extend its lifetime, which currently is only a few years. Homeowners will expect the technology to last as long as conventional windows last. It’s possible that a “re-coating” service will eventually be provided. Presently, OPVs are used primarily for portable products, such as canopies, electronic mobile devices and backpacks.
What’s encouraging about these new advances in “see-through solar” is that research and development is continuing on a national level. For the solar industry to grow, it’s important to continue to stride towards new technologies.
As NREL Research Fellow Dr. David S. Ginley said, “The fabrication of a large-area see-through solar module of these dimensions is an important step.”