[i] Photovoltaic cells are made of semiconductors, such as silicon, which is most commonly used. Solar cells are able to convert sunlight into electricity by utilizing the photoelectric effect. The photoelectric effect is the ability of matter to emit electrons when light shines on it.[ii] As sunlight’s photons come in contact with the silicon atoms of the solar cell, energy is transferred to loose electrons. Photovoltaic cells have one or more electric fields that force the freed electrons to flow in a particular direction. This flow of electrons is a current, and metal contacts on the top and bottom of the photovoltaic cells draw the current off for external use.[iii]
Rock Music Improves Performance
It was recently discovered by researchers from Queen Mary University of London and Imperial College London, that solar cells exhibit improved performance when exposed to the high frequency and pounding vibrations of today’s pop and rock music. Their research showed that solar cells improved efficiency by up to 40 percent when exposed to music. This is wonderful news for those working to lower the cost of printed solar cells. [iv] Scientists at Queen Mary University of London and Imperial College London grew billions of zinc oxide nano rods and covered them with active polymer to create a device that converts sunlight into electricity. The properties of zinc oxide material allowed the researchers to observe that sound levels as low as 75 decibels greatly improved the solar cell performance. 75 decibels is the equivalent of roadside noise or a running vacuum cleaner. Music was chosen over basic flat sounds because it allowed the researchers to observe how pitch affected the solar cells’ performance. Their most drastic observation was the difference between pop music and classical. This was due to the solar cells responding better to higher pitches found in pop music. These results were surprising to leaders of the study. It was thought that the sound waves would produce random fluctuations that would cancel each other out and have no significant effect on electrical output.[v] This discovery could allow devices that are exposed to acoustic vibrations, such as air conditioning units or within cars, to be powered.
Inexpensive Material Drives Down Cost
As stated above, silicon has been the most frequently used material for solar cells. Recently however, researchers have been working with a new material that could drastically reduce solar cell costs. The average solar panel cost approximately 75 cents a watt, but developing technology could reduce that cost to 10 to 20 cents per watt. Perovskites are dramatically cheaper to obtain then silicon and can generate as much power as today’s typical solar cell. While the conventional material used to produce solar cells is about 180 micrometers thick, new solar cells made from perovskites are less then one micrometer thick. Michael Gratzel, a famous solar cell inventor, and his team are producing some of the most efficient perovskite solar cells. Currently their solar cells are converting 15 percent of the sun’s energy into electricity. That number is expected to rise however. Based on perovskite’s current performance and its known light-conversion properties, scientists expect its efficiency to rise to 20 to 25 percent. While many solar cells produce higher then average efficiency in laboratories, Gratzel believes that perovskite cells with retain high efficiencies even when massed produced.[vi]
Researchers around the world continue to work toward improving solar cell performance and decreasing the cost. New advancements and discoveries will continue to drive the cost of solar cells down, hopefully leading to a higher rate of use.