Engineers at the the Massachusetts Institute of Technology (MIT) have their target locked-on on improving the level of efficiency that traditional photovoltaic solar cells currently have. The amount of voltage produced by photovoltaic cells are dependent on radiant energy especially light, so the cells inherently produce less voltage the hotter they get. So, how did they do it?
The technique is simple, a high-temperature material (or the modified solar cells) is exposed to sunlight and its infrared radiation is absorbed by photovoltaic cells. As it heats up, the emitted light that is failed to be absorbed by these photovoltaic cells convert the infrared radiation into wavelengths that can be captured and tuned directly to the band gap of the photovoltaic cells beneath it.
They called the new thermophotovoltaic device, Solar Thermophotovoltaic (STPV) and it’s based on nanotechnology.
Theoretically, it has been estimated that these devices could be 80 percent more efficient, but their previous attempts on the same devices were operated at efficiencies of under 1 percent. For now, the team reconcile the efficiency at 3.2 percent with an expectation to increase upto 20 percent to make it executable commercially.
“Our device is planar and compact and could become a viable option for high-performance solar thermophotovoltaic energy conversion,” says the team.
For reference, read A nanophotonic solar thermophotovoltaic device.
[Video Credit: MITMechE; Image Credit: John Freidah via MIT]