In order to bring forward the time where solar energy can stand alongside more traditional forms of power generation, solar panels must be constructed using the highest efficiency photovoltaic cells, but be manufactured as cheaply as possible.
A new assembly line test for solar quantum efficiency, developed in the US by the National Renewable Energy Laboratory (NREL), assesses the quality of individual solar cells 1,000 faster than previous tests.
The Flash Quantum Efficiency System for Solar Cells, or Flash QE, use LED lights to test how well each solar cell converts certain wavelengths of light in the solar spectrum – red or blue, for instance – from sunlight into electricity. In this way, solar cells can be sorted and matched to their specific quantum efficiency and placed in the same solar panel, maximising energy efficiency of the system.
Previously, only one cell in 1,000 could be tested in this way, with assessments taking up to 20 minutes per cell. Flash QE is so fast it can be incorporated into the manufacturing line, resulting, according to the NREL, in “significant jumps in the efficiency values of future solar modules and arrays that power the fast-growing solar industry as well as much better manufacturing line diagnostics.”
Flash QE is the brainchild two NREL scientists, David Young and Brian Egaas, who used $1000 to buy LEDs in every colour of the rainbow so they could shoot colours at a solar cell in an effort to try and improve quantum efficiency testing. It wasn’t until a third investigator, Pauls Stradins, suggested they think about the system in terms of the human brain, where data is computed all at once, that “a light just kind of went on.”
The group licensed their prototype quantum efficiency system, Real-time QE, to startup company Tau Science who re-branded it Flash QE and have since patented many parallel projects to the system.
The technology won a 2011 R&D 100 Award as one of the year’s most significant innovations.