New system set to be the most efficient solar energy source

Arizona Public Service (APS) recently started testing what it hopes to be the world’s most efficient solar cells at its Solar Technology and Research Center in Tempe, Ariz. The cells, which convert sunlight directly into electricity, have the potential to make solar energy more cost-competitive with conventional energy sources.

The Spectrolab division of the Boeing Co. developed the new photovoltaic technology, and similar systems have been used to power spacecraft, like the Mars Rovers. The new device uses concentrating triple junction solar cells, which are composed of three layers of semiconducting material, each of which extracts energy from a different part of the solar light spectrum. The efficiency is further enhanced by a system of mirrors that concentrates the sunlight by 500 times onto each cell. As a result, the new system is expected to be about 50% more efficient at converting sunlight into electricity than other technology APS has tested to date.