As of 2015, some efficient solar panels include Sharp's 37.9 percent efficient solar cells, Sharp's 44.4 percent efficient solar panels and the solar cells from the Spanish solar research institute IES and the Spanish university UPM. Soitec and Fraunhofer Institute have produced solar cells that are 46 percent efficient.
Soitec and Fraunhofer Institute's solar cells are the most efficient in the world. These cells, which make use of triple-junction, concentrator solar cell technology, are extremely expensive and, therefore, are not used in residential or commercial locations. They are, however, used by NASA for space-related applications. Sharp's 44 percent efficient solar cells were the most efficient in the world before those of Soitec and Fraunhofer Institute; however, they do still hold the world record for the amount of triple-junction, concentrator solar cells.
With significantly less efficiency than the previous two, Sharp's 37.9 percent efficient solar cells are triple-junction, non-concentrator cells. These cells don't use anything to concentrate the light, making them much less expensive than more efficient concentrators. IES and UPM's solar cells are 32.6 percent efficient and are two-junction concentrators. Like Soitec and Fraunhofer Institute's, these cells are not used in residential or commercial applications. SunPower's 21.5 percent efficient solar modules are the most efficient modules in the commercial market.