As conserving finite resources becomes an increasing priority, scientists have been consistently successful in discovering alternate renewable energies. One of these alternatives is solar energy. Solar panels absorb powerful rays from the sun and convert them into power resources, which are used in both residential and commercial areas.
However, solar panels still suffer from a list of setbacks that offset their usefulness. One of these ailments is overheating. When solar panels are exposed to too high temperatures, their efficiency and performance is hindered.
Electrical engineers are now busy trying to figure out how to overcome the heating problem and retain efficiency. Researchers at Rice University in Texas think that they may have found the answer. The solution involves capturing the thermal photons that the solar panels release.
Junichiro Kono of Rice’s Brown School of Engineering explains:
“Thermal photons are just photons emitted from a hot body. If you look at something hot with an infrared camera, you see it glow. The camera is capturing these thermally excited photons.”
Solar panels essentially have nowhere to send excess photons, which is why researchers want to reroute the extra heat and convert it into more electricity. Gururaj Naik, an assistant professor of electrical and computer engineering at Rice University, told PV Magazine, “Any hot surface emits light as thermal radiation.
“The problem is thermal radiation is broadband, while the conversion of light to electricity is efficient only if the emission is in a narrow band. By squeezing all the wasted thermal energy into a small spectral region, we can turn it into electricity very efficiently. The theoretical prediction is that we can achieve 80% efficiency.”
The engineers have created a device that will direct the photons emitted as heat into the narrower band. It utilizes ‘a film of carbon nanotubes,’ which forces the electrons to move in one direction. The researchers say the device can operate at a maximum temperature of 700 degrees Celsius.
They compiled a report entitled ‘Macroscopically Aligned Carbon Nanotubes as a ‘Refractory Platform for Hyperbolic Thermal Emitters’ published in the journal ACS Photonics. The research is only in its beginning phases; however, the engineers are optimistic that panels will soon run at four times the efficiency.
Hutchins, Mark. “Harnessing Heat for 80% Theoretical Efficiency.” Pv Magazine International, 29 July 2019, www.pv-magazine.com/2019/07/29/harnessing-heat-for-80-theoretical-efficiency
“Macroscopically Aligned Carbon Nanotubes as a Refractory Platform for Hyperbolic Thermal Emitters.” ACS Photonics, pubs.acs.org/doi/abs/10.1021/acsphotonics.9b00452