First Solar today said a test cell using its cadmium telluride solar technology set a new world record of 17.3 percent efficiency.
The world's most valuable solar company said the cell's performance, confirmed by the U.S. Department of Energy's National Renewable Energy Lab, topped the previous world record of 16.7 percent set in 2001.
A solar cell's efficiency is the percentage of sunlight that ends up being converted to electricity.
The announcement by First Solar, which rarely trumpets the performance of its test cells, comes a few months after rising competitor General Electric said one of its cadmium telluride modules had recorded the highest efficiency ever for the photovoltaic solar industry's lowest cost technology.
GE in April said its record-setting panel logged an efficiency of 12.8 percent. On Tuesday, however, First Solar said one of its modules recorded an efficiency of 13.4 percent. Both were confirmed by the U.S. Department of Energy's NREL.
Solar cells are packaged together to make modules, and that process reduces their overall efficiency.
But the results of a single test cell or module in the lab vary dramatically from those of the same products rolling off the production line.
First Solar, for instance, said the average efficiency of its modules in the first quarter was 11.7 percent. The company has a goal to reach efficiencies of 13.5 percent to 14.5 percent by the end of 2014 in full-scale production.
Cadmium telluride panels are cheaper to produce, but less efficient, than the crystalline silicon panels that dominate the market. Commercial efficiency percentages for silicon-based panels range from the high teens to low 20s.