Of all the green building technologies available to the construction industry, spray-on solar cells could become one of the most important. Everyone wants to decrease their carbon footprint and increase their energy efficiency, and solar panels are one way of accomplishing those goals. But the expense and inconvenience of current solar panel technology has been a major stumbling block for large-scale adoption of solar power. All that is changing with the advent of spray-on solar cells.
The “efficiency” of a solar cell is the fraction of light hitting a cell which is converted to useful power. Conventional silicone-based cells have about 25% efficiency. Spray-on cells have 11% efficiency, and when combined with the plentiful and inexpensive perskovite material, can reach efficiency levels of 19%. Recent lab trials have amped up the efficiency of spray-on cells up to 40% efficiency.
As spray-on solar efficiency improves, so does the potential for spray-on solar to make a huge dent in the green building industry. Because a spray-on solar cell rig looks a lot like a car painting rig, solar cells can be sprayed onto literally any surface. Instead of installing rooftop solar panels piecemeal, an entire roof could be coated in solar cell material for a fraction of the cost of a solar panel array.
Currently, residential applications of spray-on solar involve converting traditional windows into solar cells. The first company to develop spray-on solar cells, New Energy Technologies, Inc., has patented the SolarWindow coating that, when applied to glass windows or tinted plastic film, enables any transparent surface to generate electricity. The SolarWindow coating collects energy even from low-intensity irradience from artificial light sources. Another benefit of this SolarWindow technology is that it doesn’t require high-temperature or high-vacuum production methods. Because it’s sprayed on at room temperature, SolarWindow production isn’t as resource-intensive as is the production of conventional solar cells.