Engineering researchers at Queen Mary University and the Imperial College of London have created photovoltaic (PV) cells that work better when they hear rock music. (Hey, I do too!)
The PV cells are made by growing zinc-oxide nanorods. Zinc-oxide is a semiconductor material with piezoelectric characteristics. It’s the latter property that converts sound into electricity. The scientists found that sounds as low as 75 decibels - slightly louder than a vacuum cleaner - can increase the efficiency of the solar cell by up to 45%.
Although any sound at a high enough level can trigger the effect, it was more pronounced in the presence of rock and pop music. The researchers concluded that rock-and-roll’s high frequencies were favored by the solar cells. (My son - who plays bass guitar - is less than impressed with their tonal preference, but that’s his problem.)
As an added bonus, the zinc-oxide cells are inexpensive to produce. Semiconductors made from zinc-oxide can be transparent, allowing windows - or virtually any surface - to become a photovoltaic cell. There’s a lot of innovative research regarding spray-on PV cells, but one problem is their low efficiency. If they can tune these cells to respond to the frequencies present in typical city noise, whose levels are usually above 70 dB, they might overcome that shortcoming and make PV cells as ubiquitous as paint.
I think Jimmy Page is smiling.