MIT Team Use Nanomaterials To Double Energy Efficiency Of Solar Cells Through Converting Waste Heat To Usable Energy

The new experiment solar cell that was recently created by MIT researchers could massively increase the amount of power that is generated by a given area of panels and still reduces the amount of waste heat lost. The scientist says they have broken the "Shockley-Queisser limit." The Shockley-Queisser limit is the theoretical maximum efficiency of solar panels which is somewhere around 32 percent for most standard silicon-based ones.

According to the scientists, you can get around this through tricks like stacking cells. However, there is a better way according to David Bierman, a doctoral student in the MIT team which is thermophotovoltaics a process used to turn the solar energy into heat and then re-emitted as the light that is better suited for the cell to absorb. What you need to understand first is that solar panels work efficiently with a wavelength of light. Sometimes, the ultraviolet is too short while the infrared is too long.

It follows that only some of the broad-spectrum radiation emitted from the sunlight is at the required 600nm thereby limiting the amount of energy the cell can pull out of that radiation. It is one of the components of the Shockley-Queisser limit. The MIT team has succeeded in adding a step between the sun and the cell. The step involves a highly engineered structure of carbon nanotubes which are perfect absorber over the entire color spectrum.

Heat is undesired in a solar panel because it only leads to a loss of energy. In the new solar panel by MIT team, the heat is not allowed to dissipate and instead, the carbon nanostructure converts the heat back into light at the exact wavelength. The result was a massive increase in energy efficiency in the new solar panel.