Researchers in China are working on indoor photovoltaic panels, capable of converting energy collected from light emitted by commonly used indoor light sources into electricity. This technological advance could serve to power various connected devices, for example.

At the moment, photovoltaic panels only work with solar energy, and therefore outdoors, and often with quite low yields. On average, they can generally convert just 5 to 20% of the energy collected into electricity. A new record of 32.5% has just been set, albeit in a laboratory setting.

Meanwhile, in China, researchers at the Academy of Sciences in Beijing have just tested new solar cells compatible with light emitted from indoor lights. They subjected selenium (Se) solar cells to emission spectra of commonly used indoor light sources in the range of 400 to 700 nm. The first results proved convincing, since these cells showed a yield of about 15%, under strong indoor lighting (1000 lux), with no loss of efficiency whatever the exposure time. The energy thus recovered, even if minimal, could very well be sufficient to power certain connected devices.

Selenium is a material that has the unique ability to convert heat into power without losing efficiency over time. And because it is relatively flexible, it is suited to the production of different-sized indoor panels. To optimize its efficiency, various chemical components (non-toxic, according to the published paper) had to be added.

For the moment, these are only prototypes, developed in a laboratory, but the idea of one day fitting buildings with photovoltaic panels that can recover energy through indoor lighting is gaining ground.

 - AFP Relaxnews