A new record for concentrated photovoltaics efficiency has been broken by Solar Junction, the same company that announced a 41.4% efficiency in February. The new score is 43.5% and their multi-junction solar cells can be produced right away.
Solar Junction’s effective photovoltaic module is only 5.5 mm x 5.5 mm in size. If we would expose the cell to sunlight directly, then we’d say the light hitting it is one sun in intensity. A regular solar cell can’t exceed a certain amount of theoretical efficiency, but cells that have light concentrated onto them several hundred times (up to 1,000 suns), can.
One big issue of concentrated photovoltaics is that they have to be kept as cool as possible, since heat would instantly destroy a normal solar cell. That’s the reason why the cells used in concentrated sunlight approaches are very expensive, and take advantage of the entire light spectrum to their best. They can also hold up to much higher temperatures.
For example, Solar Junction’s newly designed cell is not a technological breakthrough compared to the earlier version, but the 2.1% difference lies in the way that the light spectrum has been partitioned to increase its efficiency.
Heat can also play an important role in the overall efficiency of a solar powered system, since it can be used to heat water and create electricity or compensate for the electricity usage for heating homes.